Sandbox ID Gastrointestinal and Intraabdominal

# Anthrax,  gastrointestinal
- 1. Gastrointestinal anthrax 
- Preferred regimen (1): Ciprofloxacin 400 mg IV q8h AND Clindamycin 600 mg IV q8h
- Preferred regimen (2): Ciprofloxacin 400 mg IV q8h AND Penicillin G 4 MU every 4-6 hours
- Preferred regimen (3): Ciprofloxacin 400 mg IV q8h AND Meropenem 1 gm IV q6 to 8 hours
- Preferred regimen (4): Ciprofloxacin 400 mg IV q8h AND Rifampin 300 mg q12h
- Preferred regimen (5): Doxycycline 100 mg IV q12h  AND Clindamycin 600 mg IV q8h
- Preferred regimen (6): Doxycycline 100 mg IV q12h  AND Penicillin G 4 MU every 4-6 hours
- Preferred regimen (7): Doxycycline 100 mg IV q12h  AND Meropenem 1 gm IV q6 to 8 hours
- Preferred regimen (8): Doxycycline 100 mg IV q12h  AND Rifampin 300 mg q12h
- Note: Treatment for 60 days is recommended to avoid relapse or breakthrough of incubating disease. If initial therapy is intravenous, then convert to oral administration (Ciprofloxacin or Doxycycline) when clinically indicated. Steroids may be considered as an adjunct therapy for patients with severe edema and for meningitis. For pregnant women, avoid Doxycycline. Use Ciprofloxacin and switch to oral penicillin once susceptibilities are known.

# Appendicitis
- 1. Community-acquired infection in adults 
- 1.1. Mild-to-moderate severity (perforated or abscessed appendicitis and other infections of mild-to-moderate severity):
- 1.1.1. Single agent:
- Preferred regimen (1): Cefoxitin 2 g IV q6h
- Preferred regimen (2): Ertapenem 1 g IV q24h
- Preferred regimen (3): Moxifloxacin 400 mg IV q24h
- Preferred regimen (4): Tigecycline 100 mg initial dose, THEN 50 mg IV q12h
- Preferred regimen (5): Ticarcillin-clavulanic acid 3.1 g IV q6h; FDA labeling indicates 200 mg/kg/day in divided doses every 6 h for moderate infection
- 1.1.2. Combination:
- Preferred regimen (1): Cefazolin 12 g IV q8h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (2): Cefuroxime 1.5 g IV q8h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (3): Ceftriaxone 12 g IV q1224 h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (4): Cefotaxime 12 g IV  q68 h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (5): Ciprofloxacin 400 mg IV q12h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (6): Levofloxacin 750 mg IV  q24h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- 1.2. High risk or severity (severe physiologic disturbance, advanced age, or immunocompromised state):
- 1.2.1. Single agent:
- Preferred regimen (1): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h
- Preferred regimen (2): Meropenem 1 g IV q8h
- Preferred regimen (3): Doripenem 500 mg IV q8h
- Preferred regimen (4): Piperacillin-tazobactam 3.375 g IV q6h
- 1.2.2. Combination:
- Preferred regimen (1): Cefepime 2 g  q812 h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (2): Ceftazidime 2 g q8h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (3): Ciprofloxacin 400 mg q12h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (4): Levofloxacin  750 mg q24h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Note: Antimicrobial therapy of established infection should be limited to 47 days, unless it is difficult to achieve adequate source control. Longer durations of therapy have not been associated with improved outcome.
- 2. Health CareAssociated Complicated Intra-abdominal Infection 
- 2.1. Less than 20% Resistant Pseudomonas aeruginosa, Extended-spectrum B-lactamase-producing Enterobacteriaceae, Acinetobacter, or other  multidrug resistant gram-negative bacilli:
- Preferred regimen (1): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Ceftazidime 2 g IV q8h AND Metronidazole 500 mg q812 h or 1500 mg q24h
- Preferred regimen (2): Imipenem-cilastatin 500 mg IV 6 h OR 1 g  q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Ceftazidime 2 g IV q8h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (3): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Ceftazidime 2 g IV q8h AND Metronidazole 500 mg IV every 812 h or 1500 mg q24h
- Preferred regimen (4): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Cefepime 2 g IV q812 h AND Metronidazole 500 mg q812 h or 1500 mg q24h
- Preferred regimen (5): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Cefepime 2 g IV q812 h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (6): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Cefepime 2 g IV q812 h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- 2.2. Extended-spectrum B-lactamase-producing Enterobacteriaceae:
- Preferred regimen (1): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (2): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (3): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (4): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (5): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (6): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (7): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (8): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (9): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- 2.3. Pseudomonas aeruginosa with more than 20% resistant to ceftazidime:
- Preferred regimen (1): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (2): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (3): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (4): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (5): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (6): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (7): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (8): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (9): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- 2.4.Methicillin-resistant Staphylococcus aureus (MRSA):
- Preferred regimen: Vancomycin 1520 mg/kg IV q812 h
- Note: Antimicrobial therapy of established infection should be limited to 47 days, unless it is difficult to achieve adequate source control. Longer durations of therapy have not been associated with improved outcome.
- 3. Community-acquired infection in pediatric patients
- 3.1. Single agent:
- Preferred regimen (1): Ertapenem 3 months to 12 years 15 mg/kg bid (not to exceed 1 g/day) Every 12 h, older than 13 years 1 g/day Every 24 h OR
- Preferred regimen (2): Meropenem 60 mg/kg/day q8h
- Preferred regimen (3): Imipenem-cilastatin 60100 mg/kg/day IV q6h
- Preferred regimen (4): Ticarcillin-clavulanate 200300 mg/kg/day IV of ticarcillin component q46 h
- Preferred regimen (5): Piperacillin-tazobactam 200300 mg/kg/day IV of piperacillin component q68 h
- 3.2.Combination:
- Preferred regimen (1): Ceftriaxone 5075 mg/kg/day q1224 h, AND Metronidazole 3040 mg/kg/day q8h
- Preferred regimen (2): Cefotaxime 150200 mg/kg/day q68 h, AND Metronidazole 3040 mg/kg/day q8h
- Preferred regimen (3): Cefepime 100 mg/kg/day q12h, AND Metronidazole 3040 mg/kg/day q8h
- Preferred regimen (4): Ceftazidime 150 mg/kg/day q8 h, AND Metronidazole 3040 mg/kg/day q8h
- Preferred regimen (5): Gentamicin 37.5 mg/kg/day q24 h, AND Metronidazole 3040 mg/kg/day q8h  Ampicillin 200 mg/kg/day q6h
- Preferred regimen (6): Gentamicin 37.5 mg/kg/day q24 h, AND Clindamycin 2040 mg/kg/day q68 h  Ampicillin 200 mg/kg/day q6h
- Preferred regimen (7): Tobramycin 3.07.5 mg/kg/day q824 h, AND Metronidazole 3040 mg/kg/day q8h  Ampicillin 200 mg/kg/day q6h
- Preferred regimen (8): Tobramycin 3.07.5 mg/kg/day q824 h, AND Clindamycin 2040 mg/kg/day q68 h  Ampicillin 200 mg/kg/day q6h
- Note: Antimicrobial therapy of established infection should be limited to 47 days, unless it is difficult to achieve adequate source control. Longer durations of therapy have not been associated with improved outcome.

# Biliary sepsis
- 1. Community-acquired acute cholecystitis of mild-to-moderate severity 
- Preferred regimen (1): Cefazolin  12 g IV q8h
- Preferred regimen (2): Cefuroxime 1.5 g IV q8h
- Preferred regimen (3): Ceftriaxone 12 g IV q1224 h
- 2. Community-acquired acute cholecystitis of severe physiologic disturbance, advanced age, or immunocompromised state 
- Preferred regimen (1):Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (2):Meropenem  1 g IV q8h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (3):Doripenem 500 mg IV q8h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (4):Piperacillin-tazobactam 3.375 g IV q6h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (5):Ciprofloxacin  400 mg IV q12h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (6):Levofloxacin  750 mg IV q24h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (7):Cefepime  2 g IV q812h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- 3. Acute cholangitis following bilio-enteric anastamosis of any severity 
- Preferred regimen (1): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (2): Meropenem 1 g IV q8h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (3): Doripenem 500 mg IV q8h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (4): Piperacillin-tazobactam 3.375 g IV q6h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (5): Ciprofloxacin 400 mg IV q12h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (6): Levofloxacin 750 mg IV q24h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (7): Cefepime 2 g IV q812h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- 4. Health care-associated biliary infection of any severity 
- Preferred regimen (1): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h AND Vancomycin 1520 mg/kg IV q812 h
- Preferred regimen (2): Meropenem 1 g IV q8h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h AND Vancomycin 1520 mg/kg IV q812 h
- Preferred regimen (3): Doripenem 500 mg IV q8h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h AND Vancomycin 1520 mg/kg IV q812 h
- Preferred regimen (4): Piperacillin-tazobactam 3.375 g IV q6h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h AND Vancomycin 1520 mg/kg IV q812 h
- Preferred regimen (5): Ciprofloxacin 400 mg IV q12h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h AND Vancomycin 1520 mg/kg IV q812 h
- Preferred regimen (6): Levofloxacin 750 mg IV q24h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h AND Vancomycin 1520 mg/kg IV q812 h
- Preferred regimen (7): Cefepime 2 g IV q812h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h AND Vancomycin 1520 mg/kg IV q812 h
- Note: Antimicrobial therapy of established infection should be limited to 47 days, unless it is difficult to achieve adequate source control. Longer durations of therapy have not been associated with improved outcome.

# Cholangitis
- 1. Community-acquired acute cholecystitis of mild-to-moderate severity 
- Preferred regimen (1): Cefazolin  12 g IV q8h
- Preferred regimen (2): Cefuroxime 1.5 g IV q8h
- Preferred regimen (3): Ceftriaxone 12 g IV q1224 h
- 2. Community-acquired acute cholecystitis of severe physiologic disturbance, advanced age, or immunocompromised state 
- Preferred regimen (1): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (2): Meropenem  1 g IV q8h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (3): Doripenem 500 mg IV q8h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (4): Piperacillin-tazobactam 3.375 g IV q6h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (5): Ciprofloxacin  400 mg IV q12h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (6): Levofloxacin  750 mg IV q24h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (7): Cefepime  2 g IV q812h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- 3. Acute cholangitis following bilio-enteric anastamosis of any severity 
- Preferred regimen (1): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (2): Meropenem 1 g IV q8h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (3): Doripenem 500 mg IV q8h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (4): Piperacillin-tazobactam 3.375 g IV q6h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (5): Ciprofloxacin 400 mg IV q12h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (6): Levofloxacin 750 mg IV q24h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (7): Cefepime 2 g IV q812h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- 4. Health care-associated biliary infection of any severity 
- Preferred regimen (1): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h AND Vancomycin 1520 mg/kg IV q812 h
- Preferred regimen (2): Meropenem 1 g IV q8h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h AND Vancomycin 1520 mg/kg IV q812 h
- Preferred regimen (3): Doripenem 500 mg IV q8h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h AND Vancomycin 1520 mg/kg IV q812 h
- Preferred regimen (4): Piperacillin-tazobactam 3.375 g IV q6h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h AND Vancomycin 1520 mg/kg IV q812 h
- Preferred regimen (5): Ciprofloxacin 400 mg IV q12h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h AND Vancomycin 1520 mg/kg IV q812 h
- Preferred regimen (6): Levofloxacin 750 mg IV q24h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h AND Vancomycin 1520 mg/kg IV q812 h
- Preferred regimen (7): Cefepime 2 g IV q812h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h AND Vancomycin 1520 mg/kg IV q812 h
- Note: Antimicrobial therapy of established infection should be limited to 47 days, unless it is difficult to achieve adequate source control. Longer durations of therapy have not been associated with improved outcome.

# Cholecystitis
- 1. Community-acquired acute cholecystitis of mild-to-moderate severity 
- Preferred regimen (1): Cefazolin  12 g IV q8h
- Preferred regimen (2): Cefuroxime 1.5 g IV q8h
- Preferred regimen (3): Ceftriaxone 12 g IV q1224 h
- 2. Community-acquired acute cholecystitis of severe physiologic disturbance, advanced age, or immunocompromised state 
- Preferred regimen (1):Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (2):Meropenem  1 g IV q8h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (3):Doripenem 500 mg IV q8h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (4):Piperacillin-tazobactam 3.375 g IV q6h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (5):Ciprofloxacin  400 mg IV q12h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (6):Levofloxacin  750 mg IV q24h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (7):Cefepime  2 g IV q812h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- 3. Acute cholangitis following bilio-enteric anastamosis of any severity 
- Preferred regimen (1): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (2): Meropenem 1 g IV q8h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (3): Doripenem 500 mg IV q8h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (4): Piperacillin-tazobactam 3.375 g IV q6h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (5): Ciprofloxacin 400 mg IV q12h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (6): Levofloxacin 750 mg IV q24h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (7): Cefepime 2 g IV q812h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h
- 4. Health care-associated biliary infection of any severity 
- Preferred regimen (1): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h AND Vancomycin 1520 mg/kg IV q812 h
- Preferred regimen (2): Meropenem 1 g IV q8h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h AND Vancomycin 1520 mg/kg IV q812 h
- Preferred regimen (3): Doripenem 500 mg IV q8h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h AND Vancomycin 1520 mg/kg IV q812 h
- Preferred regimen (4): Piperacillin-tazobactam 3.375 g IV q6h, AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h AND Vancomycin 1520 mg/kg IV q812 h
- Preferred regimen (5): Ciprofloxacin 400 mg IV q12h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h AND Vancomycin 1520 mg/kg IV q812 h
- Preferred regimen (6): Levofloxacin 750 mg IV q24h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h AND Vancomycin 1520 mg/kg IV q812 h
- Preferred regimen (7): Cefepime 2 g IV q812h AND Metronidazole  500 mg IV q812 h OR 1500 mg q24h AND Vancomycin 1520 mg/kg IV q812 h
- Note(1): Antimicrobial therapy of established infection should be limited to 47 days, unless it is difficult to achieve adequate source control. Longer durations of therapy have not been associated with improved outcome.
- Note(2): Patients undergoing cholecystectomy for acute cholecystitis should have antimicrobial therapy discontinued within 24 h unless there is evidence of infection outside the wall of the gallbladder.

# Diverticulitis
- 1. Community-acquired infection in adults 
- 1.1. Mild-to-moderate severity (perforated or abscessed appendicitis and other infections of mild-to-moderate severity):
- 1.1.1. Single agent:
- Preferred regimen (1): Cefoxitin 2 g IV q6h
- Preferred regimen (2): Ertapenem 1 g IV q24h
- Preferred regimen (3): Moxifloxacin 400 mg IV q24h
- Preferred regimen (4): Tigecycline 100 mg initial dose, THEN 50 mg IV q12h
- Preferred regimen (5): Ticarcillin-clavulanic acid 3.1 g IV q6h; FDA labeling indicates 200 mg/kg/day in divided doses every 6 h for moderate infection
- 1.1.2. Combination:
- Preferred regimen (1): Cefazolin 12 g IV q8h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (2): Cefuroxime 1.5 g IV q8h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (3): Ceftriaxone 12 g IV q1224 h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (4): Cefotaxime 12 g IV  q68 h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (5): Ciprofloxacin 400 mg IV q12h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (6): Levofloxacin 750 mg IV  q24h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- 1.2. High risk or severity (severe physiologic disturbance, advanced age, or immunocompromised state):
- 1.2.1. Single agent:
- Preferred regimen (1): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h
- Preferred regimen (2): Meropenem 1 g IV q8h
- Preferred regimen (3): Doripenem 500 mg IV q8h
- Preferred regimen (4): Piperacillin-tazobactam 3.375 g IV q6h
- 1.2.2. Combination:
- Preferred regimen (1): Cefepime 2 g  q812 h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (2): Ceftazidime 2 g q8h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (3): Ciprofloxacin 400 mg q12h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (4): Levofloxacin  750 mg q24h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Note: Antimicrobial therapy of established infection should be limited to 47 days, unless it is difficult to achieve adequate source control. Longer durations of therapy have not been associated with improved outcome.
- 2. Health CareAssociated Complicated Intra-abdominal Infection 
- 2.1. Less than 20% Resistant Pseudomonas aeruginosa, Extended-spectrum B-lactamase-producing Enterobacteriaceae, Acinetobacter, or other  multidrug resistant gram-negative bacilli:
- Preferred regimen (1): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Ceftazidime 2 g IV q8h AND Metronidazole 500 mg q812 h or 1500 mg q24h
- Preferred regimen (2): Imipenem-cilastatin 500 mg IV 6 h OR 1 g  q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Ceftazidime 2 g IV q8h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (3): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Ceftazidime 2 g IV q8h AND Metronidazole 500 mg IV every 812 h or 1500 mg q24h
- Preferred regimen (4): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Cefepime 2 g IV q812 h AND Metronidazole 500 mg q812 h or 1500 mg q24h
- Preferred regimen (5): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Cefepime 2 g IV q812 h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (6): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Cefepime 2 g IV q812 h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- 2.2. Extended-spectrum B-lactamase-producing Enterobacteriaceae:
- Preferred regimen (1): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (2): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (3): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (4): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (5): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (6): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (7): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (8): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (9): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- 2.3. Pseudomonas aeruginosa with more than 20% resistant to ceftazidime:
- Preferred regimen (1): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (2): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (3): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (4): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (5): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (6): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (7): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (8): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (9): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- 2.4.Methicillin-resistant Staphylococcus aureus (MRSA):
- Preferred regimen: Vancomycin 1520 mg/kg IV q812 h
- Note: Antimicrobial therapy of established infection should be limited to 47 days, unless it is difficult to achieve adequate source control. Longer durations of therapy have not been associated with improved outcome.

# Esophagitis
- 1. Candida
- Preferred regimen: Fluconazole 100200 mg/day PO/IV for 14-21 days
- Alternative regimen (1): Itraconazole suspension 100200 mg PO bid
- Alternative regimen (2): Voriconazole 200 mg PO bid
- Alternative regimen (3): Amphotericin B 0.30.7 mg/kg/day IV for 7 days
- Alternative regimen (4): Caspofungin 50 mg/day IV following a 70 mg loading dose
- Alternative regimen (5): Micafungin 150 mg/day IV
- Alternative regimen (6): Anidulafungin 50 mg/day IV following a 100 mg loading dose
- Note: Maintenance therapy with Fluconazole 100200 mg/day PO in AIDS patients
- 2. Herpes simplex virus
- Preferred regimen (1): Acyclovir 5 mg/kg IV q8h for 714 days
- Preferred regimen (2): Acyclovir 400 mg 5 times daily PO for 1421 days
- Preferred regimen (3): Valacyclovir 1 g PO tid for 1421 days  maintenance suppressive therapy may be necessary in AIDS
- Alternative regimen (1): Famciclovir 500 mg bid PO for 1421 days
- Alternative regimen (2): Foscarnet 90 mg/kg q12h IV for 714 days
- 3. Cytomegalovirus
- Preferred regimen: Ganciclovir 5 mg/kg IV q12h for 1421 days
- Alternative regimen (1): Foscarnet 90 mg/kg IV q12h for 1421 days, then Foscarnet 90120 mg/kg/day IV for maintenance in AIDS patients
- Alternative regimen (2): Valganciclovir 900 mg PO bid, then 900 mg PO qd for maintenance in AIDS patients
- Note: Maintenance therapy with Ganciclovir 5 mg/kg/day IV or 6 mg/kg/day IV 5 days per week in AIDS patients
- 4. Aphthous ulceration in immunocompromised hosts
- Preferred regimen: Prednisone 40 mg/day PO for 14 days, tapered over 48 weeks
- Alternative regimen:  Thalidomide 200 mg/day PO

# Hepatic abscess
- Pending determination of bacterial versus amoebic liver abscess
- Preferred regimen (1): Metronidazole 30-40 mg/kg/day in 3 divided doses IV q8h or 500 mg po q6-8h AND Ceftriaxone 1-2 gm IV q24h OR Piperacillin-Tazobactam 3.375 gm IV q4-6h
- Preferred regimen (2): Metronidazole 30-40 mg/kg/day in 3 divided doses IV q8h or 500 mg po q6-8h AND Ciprofloxacin 400 mg IV q12h 750 mg po OR Levofloxacin 750 mg po/IV q24h
- Alternate Regimen: Metronidazole 30-40 mg/kg/day in 3 divided doses IV q8h or 500 mg po q6-8h AND Ertapenem 1 gm q24h

# Hepatitis A
- Preferred regimen:  Usually require only supportive care, with no restrictions in diet or activity.

# Hepatitis B
- Acute Hepatitis B
- Preferred regimen: No specific therapy is available for persons with acute hepatitis B; treatment is supportive.
- Prevention
- Vaccination (available since the early 1980s) continues to be the best way for dealing with the condition. Hepatitis B is preventable, and universal vaccination is probably best soloution in countries with a high prevalence.
- 1. Preexposure vaccination
- This is especially relevant in high-risk groups. There are a number of recombinant vaccines with similar efficacy, although the dosage may differ  for example:
- Recombivax HB (10 g of HBsAg)
- Child < 11 y with an HbsAg-negative mother: 2.5 g (newborn at birth)
- Child < 11 y with an HBsAg-positive mother: 5 g
- Child 1119: 5 g
- Immunocompetent adult: 10 g
- Immunosuppressed person: 40 g
- Renal dialysis patient: 40 g
- Engerix-B (20 g of HBsAg)
- Child < 10 y: 10 g (babies at birth)
- Child > 10 y: 20 g
- Adult: 20 g
- Immunosuppressed person: 40 g
- Dialysis patient: 40 g 4.6.2
- 2. Postexposure vaccination
- A combination of hepatitis B immunoglobulin (HBIg), when available, and HBV vaccine is recommended. If HBIg is available (in most countries it is not), it should be given to all children of HBs-positive mothers at the time of delivery. This is particularly important in neonates, in whom an immediate start of postexposure immunization will prevent infection in infants of HBV-infected mothers. It is important to vaccinate within 24 hours. There is no evidence of a protective effect if the vaccine is given more than 7 days after delivery.
- Direct exposure (percutaneous inoculation or transmucosal exposure) to HBsAg positive body fluid (e.g., needlestick injury):
- Hepatitis B immunoglobulin (HBIg) single intramuscular dose of 0.06 mL/kg (as soon as possible)
- Followed by a complete course of HBV vaccination (initiated within 7 days)
- Direct exposure following sexual contact with an individual with HBV:
- HBIg single intramuscular dose of 0.06 mL/kg (within 14 days; very expensive and not affordable in most places)
- Accompanied by a complete course of HBV vaccination (do not wait!).
- Chronic Hepatitis B
- 1. Patients with HBeAg-positive chronic hepatitis B
- 1.1. HBV DNA >20,000, ALT <2 times upper limit normal (ULN)
- Observe; consider treatment when ALT becomes elevated.
- Consider biopsy in persons 40 years, ALT persistently high normal >2 times upper limit normal (ULN), or with family history of HCC.
- Consider treatment if HBV DNA >20,000 IU/mL and biopsy shows moderate/severe inflammation or significant fibrosis.
- 1.2. HBV DNA >20,000, ALT >2 times upper limit normal (ULN)
- Preferred regimen (1): Pegylated IFN-alpha 180 mcg weekly SC for 48 weeks
- Preferred regimen (2): Tenofovir (TDF) Adjustment of Adult Dosage in Accordance with Creatinine Clearance:
- If creatinine clearance >50 or normal renal function give 300 mg q24 hrs
- If creatinine clearance 3049 give 300 mg q48 hrs
- If creatinine clearance 1029 give 300 mg q72-96 hrs
- If creatinine clearance <10 with dialysis give 300 mg once a week or after a total of approximately 12 hours of dialysis
- If creatinine clearance <10 without dialysis there is no recommendation
- Note: duration of treatment is minimum 1 year, continue for at least 6 months after HBeAg seroconversion
- Preferred regimen (3): Entecavir (ETV) Adjustment of Adult Dosage in Accordance with Creatinine Clearance:
- If creatinine clearance >50 give 0.5 mg PO daily for patients with no prior Lamivudine treatment, and 1 mg PO daily for patients who are refractory/resistant to lamivudine for minimum 1 year, continue for at least 6 months after HBeAg seroconversion.
- If creatinine clearance 3049 give 0.25 mg PO qd OR 0.5 mg PO q48 hr for patients with no prior Lamivudine treatment, and 0.5 mg PO qd OR 1 mg PO q 48 hr for patients who are refractory/resistant to lamivudine for minimum 1 year, continue for at least 6 months after HBeAg seroconversion.
- If creatinine clearance 1029 give 0.15 mg PO qd OR 0.5 mg PO q 72 hr for patients with no prior Lamivudine treatment, and 0.3 mg PO qd OR 1 mg PO q 72 hr for patients who are refractory/resistant to lamivudine for minimum 1 year, continue for at least 6 months after HBeAg seroconversion.
- If creatinine clearance <10 or hemodialysis or continuous ambulatory peritoneal dialysis give 0.05 mg PO qd OR 0.5 mg PO q7 days for patients with no prior Lamivudine treatment, and 0.1 mg PO qd OR 1 mg PO q 7 days for patients who are refractory/resistant to lamivudine for minimum 1 year, continue for at least 6 months after HBeAg seroconversion.
- Note: duration of treatment is minimum 1 year, continue for at least 6 months after HBeAg seroconversion
- Alternative regimen (1): Interferon alpha (IFN) 5 MU daily or 10 MU thrice weekly SC for 16 weeks
- Alternative regimen (2): Lamivudine (LAM) Adjustment of Adult Dosage in Accordance with Creatinine Clearance:
- If creatinine clearance >50 or normal renal function give 100 mg PO qd
- If creatinine clearance 3049 give 100 mg PO first dose, then 50 mg PO qd
- If creatinine clearance 1529 give 100 mg PO first dose, then 25 mg PO qd
- If creatinine clearance 5-14 give 35 mg PO first dose, then 15 mg PO qd
- If creatinine clearance <5 give 35 mg PO first dose, then 10 mg PO qd
- The recommended dose of lamivudine for persons coinfected with HIV is 150mg PO twice daily.
- Note: duration of treatment is minimum 1 year, continue for at least 6 months after HBeAg seroconversion
- Alternative regimen (3): Adefovir (ADV) Adjustment of Adult Dosage in Accordance with Creatinine Clearance:
- If creatinine clearance >50 or normal renal function give 10 mg PO daily
- If creatinine clearance 3049 give 10 mg PO every other day
- If creatinine clearance 1019 10 mg PO every third day
- If hemodialysis patients give 10 mg PO every week following dialysis
- Note: duration of treatment is minimum 1 year, continue for at least 6 months after HBeAg seroconversion
- Alternative regimen (4): Telbivudine (LdT) Adjustment of Adult Dosage in Accordance with Creatinine Clearance:
- If creatinine clearance >50 or normal renal function give 600 mg PO once daily
- If creatinine clearance 3049 600 give mg PO once every 48 hours
- If creatinine clearance <30 (not requiring dialysis) give 600 mg PO once every 72 hours
- If End-stage renal disease give 600 mg PO once every 96 hours after hemodialysis
- Note (1): duration of treatment is minimum 1 year, continue for at least 6 months after HBeAg seroconversion
- Note (2): Observe for 3-6 months and treat if no spontaneous HBeAg loss.
- Note (3): Consider liver biopsy prior to treatment if compensated.
- Note (4): Immediate treatment if icteric or clinical decompensation.
- Note (5): Interferon alpha (IFN)/ pegylated interferon-alpha (peg-IFN), Lamivudine (LAM), Adefovir (ADV), Entecavir (ETV), tenofovir disoproxil fumarate (TDF) or telbivudine (LdT) may be used as initial therapy.
- Note (6): Adefovir (ADV) not preferred due to weak antiviral activity and high rate of resistance after 1st year.
- Note (7): Lamivudine (LAM) and Telbivudine (LdT) not preferred due to high rate of drug resistance.
- Note (8): End-point of treatment  Seroconversion from HBeAg to anti-HBe.
- Note (9): Interferon alpha (IFN)  non-responders / contraindications to IFN change to Tenofovir (TDF)/Entecavir (ETV).
- 1.3. Children with elevated ALT greater than 2 times normal
- Preferred regimen(1): Interferon alpha (IFN) 6 MU/m2  SC thrice weekly with a maximum of 10 MU
- Preferred regimen(2): Lamivudine (LAM) 3 mg/kg/d PO with a maximum of 100 mg/d.
- 2. Patients with HBeAg-negative chronic hepatitis B
- 2.1. HBV DNA >2,000 IU/mL and elevated ALT >2 times normal
- Preferred regimen (1): Pegylated IFN-alpha 180 mcg weekly SC for 1 year
- Preferred regimen (2): Tenofovir (TDF) Adjustment of Adult Dosage in Accordance with Creatinine Clearance:
- If creatinine clearance >50 or normal renal function give 300 mg q24 hrs
- If creatinine clearance 3049 give 300 mg q48 hrs
- If creatinine clearance 1029 give 300 mg q72-96 hrs
- If creatinine clearance <10 with dialysis give 300 mg once a week or after a total of approximately 12 hours of dialysis
- If creatinine clearance <10 without dialysis there is no recommendation
- Note: duration of treatment is more than 1 year
- Preferred regimen (3): Entecavir (ETV) Adjustment of Adult Dosage in Accordance with Creatinine Clearance:
- If creatinine clearance >50 give 0.5 mg PO daily for patients with no prior Lamivudine treatment, and 1 mg PO daily for patients who are refractory/resistant to lamivudine
- If creatinine clearance 3049 give 0.25 mg PO qd OR 0.5 mg PO q48 hr for patients with no prior Lamivudine treatment, and 0.5 mg PO qd OR 1 mg PO q 48 hr for patients who are refractory/resistant to lamivudine
- If creatinine clearance 1029 give 0.15 mg PO qd OR 0.5 mg PO q 72 hr for patients with no prior Lamivudine treatment, and 0.3 mg PO qd OR 1 mg PO q 72 hr for patients who are refractory/resistant to lamivudine
- If creatinine clearance <10 or hemodialysis or continuous ambulatory peritoneal dialysis give 0.05 mg PO qd OR 0.5 mg PO q7 days for patients with no prior Lamivudine treatment, and 0.1 mg PO qd OR 1 mg PO q 7 days for patients who are refractory/resistant to lamivudine.
- Note: duration of treatment is more than 1 year
- Alternative regimen (1): Interferon alpha (IFN) 5 MU daily or 10 MU thrice weekly SC for 1 year
- Alternative regimen (2): Lamivudine (LAM) Adjustment of Adult Dosage in Accordance with Creatinine Clearance:
- If creatinine clearance >50 or normal renal function give 100 mg PO qd
- If creatinine clearance 3049 give 100 mg PO first dose, then 50 mg PO qd
- If creatinine clearance 1529 give 100 mg PO first dose, then 25 mg PO qd
- If creatinine clearance 5-14 give 35 mg PO first dose, then 15 mg PO qd
- If creatinine clearance <5 give 35 mg PO first dose, then 10 mg PO qd
- The recommended dose of lamivudine for persons coinfected with HIV is 150mg PO twice daily.
- Note: duration of treatment is more than 1 year
- Alternative regimen (3): Adefovir (ADV) Adjustment of Adult Dosage in Accordance with Creatinine Clearance:
- If creatinine clearance >50 or normal renal function give 10 mg PO daily
- If creatinine clearance 3049 give 10 mg PO every other day
- If creatinine clearance 1019 10 mg PO every third day
- If hemodialysis patients give 10 mg PO every week following dialysis
- Note: duration of treatment is more than 1 year
- Alternative regimen (4): Telbivudine (LdT)Adjustment of Adult Dosage in Accordance with Creatinine Clearance:
- If creatinine clearance >50 or normal renal function give 600 mg PO once daily
- If creatinine clearance 3049 600 give mg PO once every 48 hours
- If creatinine clearance <30 (not requiring dialysis) give 600 mg PO once every 72 hours
- If End-stage renal disease give 600 mg PO once every 96 hours after hemodialysis
- Note (1): duration of treatment is more than 1 year
- Note (2): Interferon alpha (IFN)/ pegylated interferon-alpha (peg-IFN), Lamivudine (LAM), Adefovir (ADV), Entecavir (ETV), tenofovir disoproxil fumarate (TDF) or telbivudine (LdT) may be used as initial therapy.
- Note (3): Adefovir (ADV) not preferred due to weak antiviral activity and high rate of resistance after 1st year.
- Note (4): Lamivudine (LAM) and Telbivudine (LdT) not preferred due to high rate of drug resistance.
- Note (5): End-point of treatment  not defined
- Note (6): Interferon alpha (IFN)  non-responders / contraindications to IFN change to Tenofovir (TDF)/Entecavir (ETV).
- 3. HBV DNA >2,000 IU/mL and elevated ALT 1->2 times normal
- Consider liver biopsy and treat if liver biopsy shows moderate/severe necroinflammation or significant fibrosis.
- 4. HBV DNA <2,000 IU/mL and ALT < upper limit normal (ULN)
- Observe, treat if HBV DNA or ALT becomes higher.
- 5. +/- HBeAg and detectable HBV DNA with Cirrhosis
- 5.1. Compensated Cirrhosis and HBV DNA >2,000
- Preferred regimen (1): Entecavir (ETV) Adjustment of Adult Dosage in Accordance with Creatinine Clearance:
- If creatinine clearance >50 give 0.5 mg PO daily for patients with no prior Lamivudine treatment, and 1 mg PO daily for patients who are refractory/resistant to lamivudine.
- If creatinine clearance 3049 give 0.25 mg PO qd OR 0.5 mg PO q48 hr for patients with no prior Lamivudine treatment, and 0.5 mg PO qd OR 1 mg PO q 48 hr for patients who are refractory/resistant to lamivudine.
- If creatinine clearance 1029 give 0.15 mg PO qd OR 0.5 mg PO q 72 hr for patients with no prior Lamivudine treatment, and 0.3 mg PO qd OR 1 mg PO q 72 hr for patients who are refractory/resistant to lamivudine.
- If creatinine clearance <10 or hemodialysis or continuous ambulatory peritoneal dialysis give 0.05 mg PO qd OR 0.5 mg PO q7 days for patients with no prior Lamivudine treatment, and 0.1 mg PO qd OR 1 mg PO q 7 days for patients who are refractory/resistant to lamivudine.
- Preferred regimen (2): Tenofovir (TDF) Adjustment of Adult Dosage in Accordance with Creatinine Clearance:
- If creatinine clearance >50 or normal renal function give 300 mg q24 hrs
- If creatinine clearance 3049 give 300 mg q48 hrs
- If creatinine clearance 1029 give 300 mg q72-96 hrs
- If creatinine clearance <10 with dialysis give 300 mg once a week or after a total of approximately 12 hours of dialysis
- If creatinine clearance <10 without dialysis there is no recommendation
- Alternative regimen (1): Lamivudine (LAM) Adjustment of Adult Dosage in Accordance with Creatinine Clearance:
- If creatinine clearance >50 or normal renal function give 100 mg PO qd
- If creatinine clearance 3049 give 100 mg PO first dose, then 50 mg PO qd
- If creatinine clearance 1529 give 100 mg PO first dose, then 25 mg PO qd
- If creatinine clearance 5-14 give 35 mg PO first dose, then 15 mg PO qd
- If creatinine clearance <5 give 35 mg PO first dose, then 10 mg PO qd
- The recommended dose of lamivudine for persons coinfected with HIV is 150mg PO twice daily.
- Alternative regimen (2): Adefovir (ADV) Adjustment of Adult Dosage in Accordance with Creatinine Clearance:
- If creatinine clearance >50 or normal renal function give 10 mg PO daily
- If creatinine clearance 3049 give 10 mg PO every other day
- If creatinine clearance 1019 give 10 mg PO every third day
- If hemodialysis patients give 10 mg PO every week following dialysis
- Alternative regimen (3): Telbivudine (LdT) Adjustment of Adult Dosage in Accordance with Creatinine Clearance:
- If creatinine clearance >50 or normal renal function give 600 mg PO once daily
- If creatinine clearance 3049 600 give mg PO once every 48 hours
- If creatinine clearance <30 (not requiring dialysis) give 600 mg PO once every 72 hours
- If End-stage renal disease give 600 mg PO once every 96 hours after hemodialysis
- Note (1): LAM and LdT not preferred due to high rate of drug resistance.
- Note (2): ADV not preferred due to weak antiviral activity and high risk of resistance after 1st year.
- Note (3): These patients should receive long-term treatment. However, treatment may be stopped in HBeAg-positive patients if they have confirmed HBeAg seroconversion and have completed at least 6 months of consolidation therapy and in HBeAg-negative patients if they have confirmed HBsAg clearance.
- 5.2. Compensated Cirrhosis and HBV DNA <2,000
- Consider treatment if ALT elevated.
- 5.3. Decompensated Cirrhosis
- Preferred regimen (1): Tenofovir (TDF) Adjustment of Adult Dosage in Accordance with Creatinine Clearance:
- If creatinine clearance >50 or normal renal function give 300 mg q24 hrs
- If creatinine clearance 3049 give 300 mg q48 hrs
- If creatinine clearance 1029 give 300 mg q72-96 hrs
- If creatinine clearance <10 with dialysis give 300 mg once a week or after a total of approximately 12 hours of dialysis
- If creatinine clearance <10 without dialysis there is no recommendation
- Preferred regimen (2): Entecavir (ETV) Adjustment of Adult Dosage in Accordance with Creatinine Clearance:
- If creatinine clearance >50 give 0.5 mg PO daily for patients with no prior Lamivudine treatment, and 1 mg PO daily for patients who are refractory/resistant to lamivudine.
- If creatinine clearance 3049 give 0.25 mg PO qd OR 0.5 mg PO q48 hr for patients with no prior Lamivudine treatment, and 0.5 mg PO qd OR 1 mg PO q 48 hr for patients who are refractory/resistant to lamivudine.
- If creatinine clearance 1029 give 0.15 mg PO qd OR 0.5 mg PO q 72 hr for patients with no prior Lamivudine treatment, and 0.3 mg PO qd OR 1 mg PO q 72 hr for patients who are refractory/resistant to lamivudine.
- If creatinine clearance <10 or hemodialysis or continuous ambulatory peritoneal dialysis give 0.05 mg PO qd OR 0.5 mg PO q7 days for patients with no prior Lamivudine treatment, and 0.1 mg PO qd OR 1 mg PO q 7 days for patients who are refractory/resistant to lamivudine.
- Preferred regimen (3): Lamivudine (LAM) AND Adefovir (ADV)
- Lamivudine (LAM) Adjustment of Adult Dosage in Accordance with Creatinine Clearance:
- If creatinine clearance >50 or normal renal function give 100 mg PO qd
- If creatinine clearance 3049 give 100 mg PO first dose, then 50 mg PO qd
- If creatinine clearance 1529 give 100 mg PO first dose, then 25 mg PO qd
- If creatinine clearance 5-14 give 35 mg PO first dose, then 15 mg PO qd
- If creatinine clearance <5 give 35 mg PO first dose, then 10 mg PO qd
- The recommended dose of lamivudine for persons coinfected with HIV is 150mg PO twice daily.
- Adefovir (ADV) Adjustment of Adult Dosage in Accordance with Creatinine Clearance:
- If creatinine clearance >50 or normal renal function give 10 mg PO daily
- If creatinine clearance 3049 give 10 mg PO every other day
- If creatinine clearance 1019 give 10 mg PO every third day
- If hemodialysis patients give 10 mg PO every week following dialysis
- Preferred regimen (4): Telbivudine (LdT) AND Adefovir (ADV)
- Telbivudine (LdT) Adjustment of Adult Dosage in Accordance with Creatinine Clearance:
- If creatinine clearance >50 or normal renal function give 600 mg PO once daily
- If creatinine clearance 3049 600 give mg PO once every 48 hours
- If creatinine clearance <30 (not requiring dialysis) give 600 mg PO once every 72 hours
- If End-stage renal disease give 600 mg PO once every 96 hours after hemodialysis
- Adefovir (ADV) Adjustment of Adult Dosage in Accordance with Creatinine Clearance:
- If creatinine clearance >50 or normal renal function give 10 mg PO daily
- If creatinine clearance 3049 give 10 mg PO every other day
- If creatinine clearance 1019 give 10 mg PO every third day
- If hemodialysis patients give 10 mg PO every week following dialysis
- Note: coordinate treatment with transplant center and refer for liver transplant.
- Life-long treatment is recommended.
- 6. +/- HBeAg and undetectable HBV DNA  with Cirrhosis
- Compensated Cirrhosis: Observe
- Uncompensated Cirrhosis: Refer for liver transplant

# Hepatitis C

## Acute Hepatitis C
- Recommendations:
- Regular laboratory monitoring is recommended in the setting of acute HCV infection. Monitoring HCV RNA (eg, every 4 weeks to 8 weeks) for 6 months to 12 months is also recommended to determine spontaneous clearance of HCV infection versus persistence of infection.
- Counseling is recommended for patients with acute HCV infection to avoid hepatotoxic insults, including hepatotoxic drugs (eg, acetaminophen) and alcohol consumption, and to reduce the risk of HCV transmission to others.
- Referral to an addiction medicine specialist is recommended for patients with acute HCV infection related to substance use.
- If the practitioner and patient have decided that a delay in treatment initiation is acceptable, monitoring for spontaneous clearance is recommended for a minimum of 6 months. When the decision is made to initiate treatment after 6 months, treating as described for chronic hepatitis C is recommended.
- If a decision has been made to initiate treatment during the acute infection period, monitoring HCV RNA for at least 12 weeks to 16 weeks before starting treatment is recommended to allow for spontaneous clearance.
- Owing to high efficacy and safety, the same regimens that are recommended for chronic HCV infection are recommended for acute infection.

## Chronic Hepatitis C
- 1. Treatment regimens for chronic hepatitis C virus genotype 1 
- 1.1. Treatment regimens for genotype 1a:
- Preferred regimen (1): Daily fixed-dose combination of Ledipasvir 90 mg AND Sofosbuvir 400 mg for 12 weeks is recommended for treatment-naive patients with HCV genotype 1a infection
- Preferred regimen (2): Daily fixed-dose combination of Paritaprevir 150 mg AND Ritonavir 100 mg AND Ombitasvir 25 mg plus twice-daily dosed Dasabuvir 250 mg AND weight-based Ribavirin(RBV) () for 12 weeks (no cirrhosis) OR 24 weeks (cirrhosis) is recommended for treatment-naive patients with HCV genotype 1a infection.
- Preferred regimen (3): Daily Sofosbuvir 400 mg plus Simeprevir 150 mg  weight-based Ribavirin(RBV) () for 12 weeks (no cirrhosis) or 24 weeks (cirrhosis) is recommended for treatment-naive patients with HCV genotype 1a infection.
- 1.2. Treatment regimens for genotype 1b:
- Preferred regimen (1): Daily fixed-dose combination of Ledipasvir 90 mg AND Sofosbuvir 400 mg for 12 weeks is recommended for treatment-naive patients with HCV genotype 1b infection.
- Preferred regimen (2): Daily fixed-dose combination of Paritaprevir 150 mg AND Ritonavir 100 mg AND Ombitasvir 25 mg plus twice-daily dosed Dasabuvir 250 mg for 12 weeks is recommended for treatment-naive patients with HCV genotype 1b infection. The addition of weight-based RBV (1000 mg ) is recommended in patients with cirrhosis.
- Preferred regimen (3): Daily Sofosbuvir 400 mg plus Simeprevir 150 mg for 12 weeks (no cirrhosis) or 24 weeks (cirrhosis) is recommended for treatment-naive patients with HCV genotype 1b infection.
- 2. Treatment regimens for chronic hepatitis C virus genotype 2  
- Preferred regimen: Daily sofosbuvir 400 mg AND weight-based RBV (1000 mg ) for 12 weeks is recommended for treatment-naive patients with HCV genotype 2 infection. Extending treatment to 16 weeks is recommended in patients with cirrhosis.
- 3. Treatment regimens for chronic hepatitis C virus genotype 3  
- Preferred regimen: Daily sofosbuvir (400 mg) and weight-based RBV (1000 mg ) for 24 weeks is recommended for treatment-naive patients with HCV genotype 3 infection.
- Alternative regimen: Daily sofosbuvir 400 mg and weight-based RBV (1000 mg ) plus weekly PEG-IFN for 12 weeks is an acceptable regimen for IFN-eligible, treatment-naive patients with HCV genotype 3 infection.
- 4. Treatment regimens for chronic hepatitis C virus genotype 4
- Preferred regimen (1): Daily fixed-dose combination of Ledipasvir 90 mg AND Sofosbuvir 400 mg for 12 weeks is recommended for treatment-naive patients with HCV genotype 4 infection.
- Preferred regimen (2): Daily fixed-dose combination of Paritaprevir 150 mg AND Ritonavir 100 mg AND Ombitasvir 25 mg AND weight-based Ribavirin(RBV) (1000 mg ) for 12 weeks is recommended for treatment-naive patients with HCV genotype 4 infection.
- Preferred regimen (3): Daily Sofosbuvir 400 mg AND weight-based RibavirinRBV (1000 mg ) for 24 weeks is recommended for treatment-naive patients with HCV genotype 4 infection.
- Alternative regimen (1): Daily Sofosbuvir 400 mg AND weight-based Ribavirin(RBV) (1000 mg ) plus weekly PEG-IFN for 12 weeks is an acceptable regimen for treatment-naive patients with HCV genotype 4 infection.
- Alternative regimen (2): Daily Sofosbuvir 400 mg plus Simeprevir 150 mg  weight-based Ribavirin(RBV) (1000 mg ) for 12 weeks is an acceptable regimen for treatment-naive patients with HCV genotype 4 infection.
- 5. Treatment regimens for chronic hepatitis C virus genotype 5  
- Preferred regimen: Daily Sofosbuvir 400 mg AND weight-based Ribavirin(RBV) (1000 mg ) plus weekly PEG-IFN for 12 weeks is recommended for treatment-naive patients with HCV genotype 5 infection.
- Alternative regimen: Weekly PEG-IFN plus weight-based Ribavirin(RBV) (1000 mg ) for 48 weeks is an alternative regimen for IFN-eligible, treatment-naive patients with HCV genotype 5 infection.
- 6. Treatment regimens for chronic hepatitis C virus genotype 6  
- Preferred regimen: Daily fixed-dose combination of Ledipasvir 90 mg AND Sofosbuvir 400 mg for 12 weeks is recommended for treatment-naive patients with HCV genotype 6 infection.
- Alternative regimen: Daily Sofosbuvir 400 mg AND weight-based Ribavirin(RBV) (1000 mg ) plus weekly PEG-IFN for 12 weeks is an alternative regimen for IFN-eligible, treatment-naive patients with HCV genotype 6 infection.

# Hepatitis D
- Preferred regimen: Interferon alpha(IFN) 5 MU daily OR 9 MU three times a week for 612 months 

# Hepatitis E
- Preferred regimen: Treatment is supportive only.

# Infectious diarrhea

## Immunocompetent
- Bacterial 
- 1. Shigella species
- Preferred regimen (1):
- Adult dose: TMP-SMZ, 160 and 800 mg, respectively bid for 3 days (if susceptible ) OR Fluoroquinolone (e.g., 300 mg Ofloxacin, 400 mg Norfloxacin, OR 500 mg Ciprofloxacin bid for 3 days)
- Pediatric dose: TMP-SMZ, 5 and 25 mg/kg, respectively bid for 3 days
- Preferred regimen (2):
- Adult dose: Nalidixic acid  1 g/d for 5 days OR Ceftriaxone; Azithromycin
- Pediatric dose:  Nalidixic acid,  55 mg/kg/d for 5 days
- 2. Non-typhi species of Salmonella
- Preferred regimen: Not recommended routinely, but if severe or patient is younger than 6 monthes or older than 50 year old or has prostheses, valvular heart disease, severe atherosclerosis, malignancy, or uremia, TMP-SMZ (if susceptible) OR Fluoroquinolone, bid for 5 to 7 days; Ceftriaxone, 100 mg/kg/d in 1 or 2 divided doses
- 3. Campylobacter species
- Preferred regimen: Erythromycin 500 mg bid for 5 days
- 4. Escherichia coli species
- 4.1. Enterotoxigenic
- Preferred regimen: TMP-SMZ, 160 and 800 mg, respectively, bid, for 3 days (if susceptible), OR Fluoroquinolone (e.g., 300 mg Ofloxacin, 400 mg Norfloxacin, or 500 mg Ciprofloxacin bid for 3 days)
- 4.2. Enteropathogenic
- Preferred regimen: TMP-SMZ, 160 and 800 mg, respectively, bid, for 3 days (if susceptible), OR Fluoroquinolone (e.g., 300 mg Ofloxacin, 400 mg Norfloxacin, or 500 mg Ciprofloxacin bid for 3 days)
- 4.3. Enteroinvasive
- Preferred regimen: TMP-SMZ, 160 and 800 mg, respectively, bid, for 3 days (if susceptible), OR Fluoroquinolone (e.g., 300 mg Ofloxacin, 400 mg Norfloxacin, or 500 mg Ciprofloxacin bid for 3 days)
- 4.4. Enterohemorrhagic
- Preferred regimen: Avoid antimotility drugs; role of antibiotics unclear, and administration should be avoided.
- 5. Aeromonas/Plesiomonas
- Preferred regimen: TMP-SMZ, 160 and 800 mg, respectively, bid for 3 days (if susceptible), Fluoroquinolone (e.g., 300 mg Ofloxacin, 400 mg Norfloxacin, or 500 mg Ciprofloxacin bid for 3 days)
- 6. Yersinia species
- Preferred regimen: Antibiotics are not usually required; Deferoxamine therapy should be withheld; for severe infections or associated bacteremia treat as for immunocompromised hosts, using combination therapy with Doxycycline, Aminoglycoside, TMP-SMZ, OR Fluoroquinolone
- 7. Vibrio cholerae O1 or O139
- Preferred regimen (1): Doxycycline 300-mg single dose
- Preferred regimen (2): Tetracycline 500 mg qid for 3 days
- Preferred regimen (3): TMP-SMZ 160 and 800 mg, respectively, bid for 3 days
- Preferred regimen (4): single-dose Fluoroquinolone
- 8. Toxigenic Clostridium difficile
- Preferred regimen: Offending antibiotic should be withdrawn if possible; Metronidazole, 250 mg qid to 500 mg tid for 3 to 10 days
- Parasites 
- 1. Giardia
- Preferred regimen: Metronidazole 250-750 mg tid  for 7-10 days
- 2. Cryptosporidium species
- Preferred regimen: If severe, consider Paromomycin, 500 mg tid for 7 days
- 3. Isospora species
- Preferred regimen: TMP-SMZ, 160 and 800 mg, respectively, bid for 7 to 10 days
- 4. Cyclospora species
- Preferred regimen: TMP/SMZ, 160 and 800 mg, respectively, bid for 7 days
- 5. Microsporidium species
- Preferred regimen: Not determined
- 6. Entamoeba histolytica
- Preferred regimen (1): Metronidazole 750 mg tid for 5 to 10 days AND Diiodohydroxyquin 650 mg tid for 20 days
- Preferred regimen (2): Metronidazole 750 mg tid for 5 to 10 days AND Paromomycin 500 mg tid for 7 days

## Immunocompromised
- Bacterial 
- 1. Shigella species:
- Preferred regimen (1):
- Adult dose: TMP-SMZ, 160 and 800 mg, respectively bid for 7 to 10 days (if susceptible ) OR Fluoroquinolone (e.g., 300 mg Ofloxacin, 400 mg Norfloxacin, OR 500 mg Ciprofloxacin bid for 7 to 10 days)
- Pediatric dose:TMP-SMZ, 5 and 25 mg/kg, respectively bid for 7 to 10 days
- Preferred regimen (2):
- Adult dose: Nalidixic acid  1 g/d for 7 to 10 days OR Ceftriaxone; Azithromycin
- Pediatric dose:  Nalidixic acid,  55 mg/kg/d for 7 to 10 days
- 2. Non-typhi species of Salmonella
- Preferred regimen: Not recommended routinely, but if severe or patient is younger than 6 monthes or older than 50 old or has prostheses, valvular heart disease, severe atherosclerosis, malignancy, or uremia, TMP-SMZ (if susceptible) OR Fluoroquinolone, bid for 14 days (or longer if relapsing); ceftriaxone, 100 mg/kg/d in 1 or 2 divided doses
- 3. Campylobacter species
- Preferred regimen: Erythromycin, 500 mg bid for 5 days (may require prolonged treatment)
- 4. Escherichia coli species
- 4.1. Enterotoxigenic
- Preferred regimen: TMP-SMZ, 160 and 800 mg, respectively, bid for 3 days (if susceptible), OR Fluoroquinolone (e.g., 300 mg Ofloxacin, 400 mg Norfloxacin, or 500 mg Ciprofloxacin bid for 3 days) (Consider fluoroquinolone as for enterotoxigenic E. coli)
- 4.2. Enteropathogenic
- Preferred regimen: TMP-SMZ, 160 and 800 mg, respectively, bid,for 3 days (if susceptible), OR Fluoroquinolone (e.g., 300 mg Ofloxacin, 400 mg Norfloxacin, or 500 mg Ciprofloxacin bid for 3 days)
- 4.3. Enteroinvasive
- Preferred regimen: TMP-SMZ, 160 and 800 mg, respectively, bid,for 3 days (if susceptible), OR Fluoroquinolone (e.g., 300 mg Ofloxacin, 400 mg Norfloxacin, or 500 mg Ciprofloxacin bid for 3 days)
- 4.4. Enterohemorrhagic
- Preferred regimen: Avoid antimotility drugs; role of antibiotics unclear, and administration should be avoided.
- 5. Aeromonas/Plesiomonas
- Preferred regimen: TMP-SMZ, 160 and 800 mg, respectively, bid for 3 days (if susceptible), Fluoroquinolone (e.g., 300 mg ofloxacin, 400 mg norfloxacin, or 500 mg Ciprofloxacin bid for 3 days)
- 6. Yersinia species
- Preferred regimen: Doxycycline, Aminoglycoside (in combination) or TMP-SMZ or Fluoroquinolone
- 7. Vibrio cholerae O1 or O139
- Preferred regimen: Doxycycline, 300-mg single dose; or Tetracycline, 500 mg qid for 3 days; or TMP-SMZ, 160 and 800 mg, respectively, bid for 3 days; or single-dose Fluoroquinolone
- 8. Toxigenic Clostridium difficile
- Preferred regimen: Offending antibiotic should be withdrawn if possible; Metronidazole, 250 mg qid to 500 mg tid for 3 to 10 days
- Parasites 
- 1. Giardia
- Preferred regimen: Metronidazole, 250-750 mg tid  for 7-10 days
- 2. Cryptosporidium species
- Preferred regimen: Paromomycin, 500 mg tid for 14 to 28 days, then bid if needed; highly active antiretroviral therapy including a protease inhibitor is warranted for patients with AIDS
- 3. Isospora species
- Preferred regimen: TMP-SMZ, 160 and 800 mg, respectively, qid for 10 days, followed by TMP-SMZ thrice weekly, or weekly Sulfadoxine (500 mg) and Pyrimethamine (25 mg) indefinitely for patients with AIDS
- 4. Cyclospora species
- Preferred regimen: TMP-SMZ, 160 and 800 mg, respectively, qid for 10 days, followed by TMP-SMZ thrice weekly indefinitely
- 5. Microsporidium species
- Preferred regimen: Albendazole, 400 mg bid for 3 weeks; highly active antiretroviral therapy including a protease inhibitor is warranted for patients with AIDS
- 6. Entamoeba histolytica
- Preferred regimen: Metronidazole, 750 mg tid for 5 to 10 days, plus either Diiodohydroxyquin, 650 mg tid for 20 days, or Paromomycin, 500 mg tid for 7 days

# Leptospirosis
- 1. Severe cases
- Preferred regimen: Benzylpenicillin 30 mg/kg up to 1.2 g IV q6h for 5-7 days
- 2. Less severe cases
- Preferred regimen: treated orally with antibiotics such as Doxycycline (2 mg/kg up to 100 mg 12-hourly for 5-7 days), Tetracycline, Ampicillin or Amoxicillin.
- Note (1): Third-generation cephalosporins, such as Ceftriaxone and Cefotaxime, and Quinolone antibiotics may also be effective.
- Note (2): Jarisch-Herxheimer reactions may occur after the start of antimicrobial therapy.
- Note (3): Monitoring and supportive care as appropriate, e.g. dialysis, mechanical ventilation.
- 3. Prevention
- Preventing infection or disease in human hosts:
- Antibiotic prophylaxis of exposed persons in areas of high exposures may be effective, e.g. soldiers (Doxycycline 200mg in one weekly dose)
- Raising awareness of the disease and its of modes of transmission.

# Pancreatitis
- 1. In patients with infected necrosis:
- Preferred regimen (1): Moxifloxacin 400mg PO/IV q24h
- Preferred regimen (2): Meropenem 0.5-1gm Iv q8h
- Preferred regimen (3): Imipenem/cilastatin 0.5 gm IV q6h
- Preferred regimen (4): Ertapenem 1gm IV/IM q24h
- Note (1): The use of antibiotics in patients with sterile necrosis to prevent the development of infected necrosis is not recommended.
- Note (2): Routine use of prophylactic antibiotics in patients with severe Acue Pancreatitis is not recommended.

# Peliosis hepatis
- Peliosis hepatis, Bartonella henselae, Bartonella quintana 
- Preferred regimen (1): Clarithromycin 500 mg bid for 8 weeks
- Preferred regimen (2): Clarithromycin Extended Release 1 gm PO q24h for 8 weeks
- Preferred regimen (3): Azithromycin 250 mg PO q24h for 8 weeks
- Preferred regimen (4): Ciprofloxacin 500750 mg PO bid for 8 weeks
- Alternative regimen (1): Erythromycin 500 mg PO qid for 8 weeks
- Alternative regimen (2): Doxycycline 100 mg PO bid for 8 weeks
- Alternative regimen (3): If severe, combination of Doxycycline 100 mg PO/IV bid AND Rifampin  300 mg PO bid

# Peptic ulcer disease
- Preferred regimen:  Combination of PPI AND Amoxicillin 1 g bid and Clarithromycin 500 mg bid for 7-10 days
- Note (1): 7-day therapy is approved with Rabeprazole; 10-day therapy is approved with Lansoprazole, Omeprazole, Pantoprazole, and Esomeprazole.
- Note (2): Metronidazole 400 mg bid may be substituted for Amoxicillin in this regimen if the patient is allergic to Penicillin.
- Alternative regimen: Bismuth subsalicylate 525 mg qid AND Metronidazole 250 mg qid AND Tetracycline 500 mg qid combined with a PPI for 14 days.

# Peritonitis, secondary to bowel  perforation
- 1. Community-acquired infection in adults 
- 1.1. Mild-to-moderate severity (perforated or abscessed appendicitis and other infections of mild-to-moderate severity):
- 1.1.1. Single agent:
- Preferred regimen (1): Cefoxitin 2 g IV q6h
- Preferred regimen (2): Ertapenem 1 g IV q24h
- Preferred regimen (3): Moxifloxacin 400 mg IV q24h
- Preferred regimen (4): Tigecycline 100 mg initial dose, THEN 50 mg IV q12h
- Preferred regimen (5): Ticarcillin-clavulanic acid 3.1 g IV q6h; FDA labeling indicates 200 mg/kg/day in divided doses every 6 h for moderate infection
- 1.1.2. Combination:
- Preferred regimen (1): Cefazolin 12 g IV q8h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (2): Cefuroxime 1.5 g IV q8h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (3): Ceftriaxone 12 g IV q1224 h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (4): Cefotaxime 12 g IV  q68 h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (5): Ciprofloxacin 400 mg IV q12h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (6): Levofloxacin 750 mg IV  q24h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- 1.2. High risk or severity (severe physiologic disturbance, advanced age, or immunocompromised state):
- 1.2.1. Single agent:
- Preferred regimen (1): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h
- Preferred regimen (2): Meropenem 1 g IV q8h
- Preferred regimen (3): Doripenem 500 mg IV q8h
- Preferred regimen (4): Piperacillin-tazobactam 3.375 g IV q6h
- 1.2.2. Combination:
- Preferred regimen (1): Cefepime 2 g  q812 h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (2): Ceftazidime 2 g q8h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (3): Ciprofloxacin 400 mg q12h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (4): Levofloxacin  750 mg q24h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Note: Antimicrobial therapy of established infection should be limited to 47 days, unless it is difficult to achieve adequate source control. Longer durations of therapy have not been associated with improved outcome.
- 2. Health CareAssociated Complicated Intra-abdominal Infection 
- 2.1. Less than 20% Resistant Pseudomonas aeruginosa, Extended-spectrum B-lactamase-producing Enterobacteriaceae, Acinetobacter, or other  multidrug resistant gram-negative bacilli:
- Preferred regimen (1): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Ceftazidime 2 g IV q8h AND Metronidazole 500 mg q812 h or 1500 mg q24h
- Preferred regimen (2): Imipenem-cilastatin 500 mg IV 6 h OR 1 g  q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Ceftazidime 2 g IV q8h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (3): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Ceftazidime 2 g IV q8h AND Metronidazole 500 mg IV every 812 h or 1500 mg q24h
- Preferred regimen (4): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Cefepime 2 g IV q812 h AND Metronidazole 500 mg q812 h or 1500 mg q24h
- Preferred regimen (5): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Cefepime 2 g IV q812 h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (6): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Cefepime 2 g IV q812 h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- 2.2. Extended-spectrum B-lactamase-producing Enterobacteriaceae:
- Preferred regimen (1): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (2): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (3): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (4): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (5): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (6): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (7): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (8): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (9): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- 2.3. Pseudomonas aeruginosa with more than 20% resistant to ceftazidime:
- Preferred regimen (1): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (2): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (3): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (4): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (5): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (6): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (7): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (8): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (9): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- 2.4.Methicillin-resistant Staphylococcus aureus (MRSA):
- Preferred regimen: Vancomycin 1520 mg/kg IV q812 h
- Note: Antimicrobial therapy of established infection should be limited to 47 days, unless it is difficult to achieve adequate source control. Longer durations of therapy have not been associated with improved outcome.

# Peritonitis, secondary to dialysis
- 1. Mild-moderate disease
- Preferred regimen (1): Piperacillin-tazobactam 3.375 g IV q6h OR 4.5 g IV q8h
- Preferred regimen (2): Ticarcillin-clavulanate 3.1 g IV q6h.
- Alternative regimen (1): Ciprofloxacin 400 mg IV q12h AND Metronidazole 1 g IV q12h
- Alternative regimen (2): Levofloxacin 750 mg IV q24h AND Metronidazole 1 g IV q12h.
- 2. Severe life-threatening disease
- Preferred regimen (1): Imipenem 500 mg IV q6h
- Preferred regimen (2): Meropenem 1 g IV q8h

# Peritonitis, secondary to ruptured  appendix
- 1. Community-acquired infection in adults 
- 1.1. Mild-to-moderate severity (perforated or abscessed appendicitis and other infections of mild-to-moderate severity):
- 1.1.1. Single agent:
- Preferred regimen (1): Cefoxitin 2 g IV q6h
- Preferred regimen (2): Ertapenem 1 g IV q24h
- Preferred regimen (3): Moxifloxacin 400 mg IV q24h
- Preferred regimen (4): Tigecycline 100 mg initial dose, THEN 50 mg IV q12h
- Preferred regimen (5): Ticarcillin-clavulanic acid 3.1 g IV q6h; FDA labeling indicates 200 mg/kg/day in divided doses every 6 h for moderate infection
- 1.1.2. Combination:
- Preferred regimen (1): Cefazolin 12 g IV q8h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (2): Cefuroxime 1.5 g IV q8h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (3): Ceftriaxone 12 g IV q1224 h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (4): Cefotaxime 12 g IV  q68 h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (5): Ciprofloxacin 400 mg IV q12h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (6): Levofloxacin 750 mg IV  q24h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- 1.2. High risk or severity (severe physiologic disturbance, advanced age, or immunocompromised state):
- 1.2.1. Single agent:
- Preferred regimen (1): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h
- Preferred regimen (2): Meropenem 1 g IV q8h
- Preferred regimen (3): Doripenem 500 mg IV q8h
- Preferred regimen (4): Piperacillin-tazobactam 3.375 g IV q6h
- 1.2.2. Combination:
- Preferred regimen (1): Cefepime 2 g  q812 h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (2): Ceftazidime 2 g q8h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (3): Ciprofloxacin 400 mg q12h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (4): Levofloxacin  750 mg q24h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Note: Antimicrobial therapy of established infection should be limited to 47 days, unless it is difficult to achieve adequate source control. Longer durations of therapy have not been associated with improved outcome.
- 2. Health CareAssociated Complicated Intra-abdominal Infection 
- 2.1. Less than 20% Resistant Pseudomonas aeruginosa, Extended-spectrum B-lactamase-producing Enterobacteriaceae, Acinetobacter, or other  multidrug resistant gram-negative bacilli:
- Preferred regimen (1): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Ceftazidime 2 g IV q8h AND Metronidazole 500 mg q812 h or 1500 mg q24h
- Preferred regimen (2): Imipenem-cilastatin 500 mg IV 6 h OR 1 g  q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Ceftazidime 2 g IV q8h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (3): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Ceftazidime 2 g IV q8h AND Metronidazole 500 mg IV every 812 h or 1500 mg q24h
- Preferred regimen (4): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Cefepime 2 g IV q812 h AND Metronidazole 500 mg q812 h or 1500 mg q24h
- Preferred regimen (5): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Cefepime 2 g IV q812 h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (6): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Cefepime 2 g IV q812 h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- 2.2. Extended-spectrum B-lactamase-producing Enterobacteriaceae:
- Preferred regimen (1): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (2): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (3): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (4): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (5): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (6): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (7): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (8): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (9): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- 2.3. Pseudomonas aeruginosa with more than 20% resistant to ceftazidime:
- Preferred regimen (1): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (2): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (3): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (4): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (5): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (6): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (7): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (8): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (9): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- 2.4.Methicillin-resistant Staphylococcus aureus (MRSA):
- Preferred regimen: Vancomycin 1520 mg/kg IV q812 h
- Note: Antimicrobial therapy of established infection should be limited to 47 days, unless it is difficult to achieve adequate source control. Longer durations of therapy have not been associated with improved outcome.
- 3. Community-acquired infection in pediatric patients
- 3.1. Single agent:
- Preferred regimen (1): Ertapenem 3 months to 12 years 15 mg/kg bid (not to exceed 1 g/day) Every 12 h, older than 13 years 1 g/day Every 24 h OR
- Preferred regimen (2): Meropenem 60 mg/kg/day q8h
- Preferred regimen (3): Imipenem-cilastatin 60100 mg/kg/day IV q6h
- Preferred regimen (4): Ticarcillin-clavulanate 200300 mg/kg/day IV of ticarcillin component q46 h
- Preferred regimen (5): Piperacillin-tazobactam 200300 mg/kg/day IV of piperacillin component q68 h
- 3.2.Combination:
- Preferred regimen(1): Ceftriaxone 5075 mg/kg/day q1224 h, AND Metronidazole 3040 mg/kg/day q8h
- Preferred regimen(2): Cefotaxime 150200 mg/kg/day q68 h, AND Metronidazole 3040 mg/kg/day q8h
- Preferred regimen(3): Cefepime 100 mg/kg/day q12h, AND Metronidazole 3040 mg/kg/day q8h
- Preferred regimen(4): Ceftazidime 150 mg/kg/day q8 h, AND Metronidazole 3040 mg/kg/day q8h
- Preferred regimen(5): Gentamicin 37.5 mg/kg/day q24 h, AND Metronidazole 3040 mg/kg/day q8h  Ampicillin 200 mg/kg/day q6h
- Preferred regimen(6): Gentamicin 37.5 mg/kg/day q24 h, AND Clindamycin 2040 mg/kg/day q68 h  Ampicillin 200 mg/kg/day q6h
- Preferred regimen(7): Tobramycin 3.07.5 mg/kg/day q824 h, AND Metronidazole 3040 mg/kg/day q8h  Ampicillin 200 mg/kg/day q6h
- Preferred regimen(8): Tobramycin 3.07.5 mg/kg/day q824 h, AND Clindamycin 2040 mg/kg/day q68 h  Ampicillin 200 mg/kg/day q6h
- Note: Antimicrobial therapy of established infection should be limited to 47 days, unless it is difficult to achieve adequate source control. Longer durations of therapy have not been associated with improved outcome.

# Peritonitis, secondary to ruptured  diverticula
- 1. Community-acquired infection in adults 
- 1.1. Mild-to-moderate severity (perforated or abscessed appendicitis and other infections of mild-to-moderate severity):
- 1.1.1. Single agent:
- Preferred regimen (1): Cefoxitin 2 g IV q6h
- Preferred regimen (2): Ertapenem 1 g IV q24h
- Preferred regimen (3): Moxifloxacin 400 mg IV q24h
- Preferred regimen (4): Tigecycline 100 mg initial dose, THEN 50 mg IV q12h
- Preferred regimen (5): Ticarcillin-clavulanic acid 3.1 g IV q6h; FDA labeling indicates 200 mg/kg/day in divided doses every 6 h for moderate infection
- 1.1.2. Combination:
- Preferred regimen (1): Cefazolin 12 g IV q8h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (2): Cefuroxime 1.5 g IV q8h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (3): Ceftriaxone 12 g IV q1224 h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (4): Cefotaxime 12 g IV  q68 h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (5): Ciprofloxacin 400 mg IV q12h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (6): Levofloxacin 750 mg IV  q24h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- 1.2. High risk or severity (severe physiologic disturbance, advanced age, or immunocompromised state):
- 1.2.1. Single agent:
- Preferred regimen (1): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h
- Preferred regimen (2): Meropenem 1 g IV q8h
- Preferred regimen (3): Doripenem 500 mg IV q8h
- Preferred regimen (4): Piperacillin-tazobactam 3.375 g IV q6h
- 1.2.2. Combination:
- Preferred regimen (1): Cefepime 2 g  q812 h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (2): Ceftazidime 2 g q8h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (3): Ciprofloxacin 400 mg q12h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (4): Levofloxacin  750 mg q24h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Note: Antimicrobial therapy of established infection should be limited to 47 days, unless it is difficult to achieve adequate source control. Longer durations of therapy have not been associated with improved outcome.
- 2. Health CareAssociated Complicated Intra-abdominal Infection 
- 2.1. Less than 20% Resistant Pseudomonas aeruginosa, Extended-spectrum B-lactamase-producing Enterobacteriaceae, Acinetobacter, or other  multidrug resistant gram-negative bacilli:
- Preferred regimen (1): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Ceftazidime 2 g IV q8h AND Metronidazole 500 mg q812 h or 1500 mg q24h
- Preferred regimen (2): Imipenem-cilastatin 500 mg IV 6 h OR 1 g  q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Ceftazidime 2 g IV q8h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (3): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Ceftazidime 2 g IV q8h AND Metronidazole 500 mg IV every 812 h or 1500 mg q24h
- Preferred regimen (4): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Cefepime 2 g IV q812 h AND Metronidazole 500 mg q812 h or 1500 mg q24h
- Preferred regimen (5): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Cefepime 2 g IV q812 h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (6): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Cefepime 2 g IV q812 h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- 2.2. Extended-spectrum B-lactamase-producing Enterobacteriaceae:
- Preferred regimen (1): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (2): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (3): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (4): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (5): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (6): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (7): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (8): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (9): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- 2.3. Pseudomonas aeruginosa with more than 20% resistant to ceftazidime:
- Preferred regimen (1): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (2): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (3): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (4): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (5): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (6): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (7): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (8): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (9): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- 2.4.Methicillin-resistant Staphylococcus aureus (MRSA):
- Preferred regimen: Vancomycin 1520 mg/kg IV q812 h
- Note: Antimicrobial therapy of established infection should be limited to 47 days, unless it is difficult to achieve adequate source control. Longer durations of therapy have not been associated with improved outcome.

# Peritonitis, spontaneous bacterial
- 1. Community-acquired Spontaneous Bacterial Peritonitis:
- Preferred regimen (1): Cefotaxime 2 g IV Q 8 h for 5 days
- Preferred regimen (2): Ceftriaxone 1 g IV bid for 5 days
- Alternative regimen: If allergic to Penicillin give Levofloxacin 500 mg IV daily for 5 days
- 2. Nosocomial Spontaneous Bacterial Peritonitis:
- Preferred regimen: Tazobactampipercillin 3.375 g IV Q 6 hrs AND Vancomycin 1 g IV Q 12 hrs for 5 days
- 3. Vancomycin-resistant Enterococcus Spontaneous Bacterial Peritonitis:
- Preferred regimen: Linezolid 600 mg po or IV q12h OR Daptomycin 6 mg/kg IV
- 4. Extended spectrum beta-lactamase Enterobacteriaceae Spontaneous Bacterial Peritonitis(ESBL Enterobacteriaceae SBP):
- Preferred regimen: Meropenem 1 g IV Q 8 h for 5-7 days

# Post-transplant infected biloma
- Preferred regimen: Linezolid 600 mg IV bid AND Ciprofloxacin 400 mg IV q12h AND Fluconazole 400 mg IV q24h 
- Alternative regimen: Daptomycin 6mg/kg per day AND Levofloxacin 750 mg IV q24h AND Fluconazole 400 mg IV q24h 

# Splenic abscess
- 1. Endocarditis, bacteremia
- Preferred regimen: Nafcillin or Oxacillin 2 gm IV q4h if MSSA
- Alternative regimen: Vancomycin 1 gm IV q12h if MRSA
- 2. Contiguous from intra-abdominal site
- 2.1. Mild-moderate disease
- Preferred regimen (1): Piperacillin-tazobactam 3.375 g IV q6h or 4.5 g IV q8h
- Preferred regimen (2): Ticarcillin-clavulanate 3.1 g IV q6h
- Alternative regimen: Ciprofloxacin 400 mg IV q12h OR Levofloxacin 750 mg IV q24h AND Metronidazole 1 g IV q12h.
- 2.2. Severe life-threatening disease
- Preferred regimen (1): Imipenem 500 mg IV q6h
- Preferred regimen (2): Meropenem 1 g IV q8h
- 3. Immunocompromised
- Preferred regimen: Amphotericin B 0.7 mg/kg IV daily
- Alternative regimen (1): Fluconazole 800 mg (12 mg/kg) loading dose, then 400 mg daily IV or PO
- Alternative regimen (2): Caspofungin 70 mg IV loading dose, then 50 mg IV daily (35 mg for moderate hepatic insufficiency);

# Tropical sprue
- Tropical sprue
- Preferred regimen (1): Folic acid 5 mg PO bid for 2 weeks, followed by 1 mg PO tid AND Tetracycline 250 mg PO qid for 46 weeks, up to 6 months in residents of the tropics who have had long-term disease
- Preferred regimen (2): Folic acid 5 mg PO bid for 2 weeks, followed by 1 mg PO tid AND Doxycycline 100 mg PO qd for 46 weeks, up to 6 months in residents of the tropics who have had long-term disease
- Alternative regimen: Folic acid 5 mg PO bid for 2 weeks, followed by 1 mg PO tid AND Ampicillin 500 mg bid for  4 weeks

# Typhlitis
- 1. Community-acquired infection in adults 
- 1.1. Mild-to-moderate severity (perforated or abscessed appendicitis and other infections of mild-to-moderate severity):
- 1.1.1. Single agent:
- Preferred regimen (1): Cefoxitin 2 g IV q6h
- Preferred regimen (2): Ertapenem 1 g IV q24h
- Preferred regimen (3): Moxifloxacin 400 mg IV q24h
- Preferred regimen (4): Tigecycline 100 mg initial dose, THEN 50 mg IV q12h
- Preferred regimen (5): Ticarcillin-clavulanic acid 3.1 g IV q6h; FDA labeling indicates 200 mg/kg/day in divided doses every 6 h for moderate infection
- 1.1.2. Combination:
- Preferred regimen (1): Cefazolin 12 g IV q8h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (2): Cefuroxime 1.5 g IV q8h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (3): Ceftriaxone 12 g IV q1224 h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (4): Cefotaxime 12 g IV  q68 h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (5): Ciprofloxacin 400 mg IV q12h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- Preferred regimen (6): Levofloxacin 750 mg IV  q24h AND Metronidazole 500 mg IV q812 h OR 1500 mg q24h
- 1.2. High risk or severity (severe physiologic disturbance, advanced age, or immunocompromised state):
- 1.2.1. Single agent:
- Preferred regimen (1): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h
- Preferred regimen (2): Meropenem 1 g IV q8h
- Preferred regimen (3): Doripenem 500 mg IV q8h
- Preferred regimen (4): Piperacillin-tazobactam 3.375 g IV q6h
- 1.2.2. Combination:
- Preferred regimen (1): Cefepime 2 g  q812 h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (2): Ceftazidime 2 g q8h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (3): Ciprofloxacin 400 mg q12h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (4): Levofloxacin  750 mg q24h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Note: Antimicrobial therapy of established infection should be limited to 47 days, unless it is difficult to achieve adequate source control. Longer durations of therapy have not been associated with improved outcome.
- 2. Health CareAssociated Complicated Intra-abdominal Infection 
- 2.1. Less than 20% Resistant Pseudomonas aeruginosa, Extended-spectrum B-lactamase-producing Enterobacteriaceae, Acinetobacter, or other  multidrug resistant gram-negative bacilli:
- Preferred regimen (1): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Ceftazidime 2 g IV q8h AND Metronidazole 500 mg q812 h or 1500 mg q24h
- Preferred regimen (2): Imipenem-cilastatin 500 mg IV 6 h OR 1 g  q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Ceftazidime 2 g IV q8h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (3): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Ceftazidime 2 g IV q8h AND Metronidazole 500 mg IV every 812 h or 1500 mg q24h
- Preferred regimen (4): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Cefepime 2 g IV q812 h AND Metronidazole 500 mg q812 h or 1500 mg q24h
- Preferred regimen (5): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Cefepime 2 g IV q812 h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- Preferred regimen (6): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g IV q6h AND Cefepime 2 g IV q812 h AND Metronidazole 500 mg IV q812 h or 1500 mg q24h
- 2.2. Extended-spectrum B-lactamase-producing Enterobacteriaceae:
- Preferred regimen (1): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (2): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (3): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (4): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (5): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (6): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (7): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (8): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (9): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- 2.3. Pseudomonas aeruginosa with more than 20% resistant to ceftazidime:
- Preferred regimen (1): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (2): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (3): Meropenem  1 g IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (4): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (5): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (6): Imipenem-cilastatin 500 mg IV q6h OR 1 g q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- Preferred regimen (7): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Gentamicin 57 mg/kg IV q24h
- Preferred regimen (8): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Tobramycin 57 mg/kg IV q24h
- Preferred regimen (9): Doripenem 500 mg IV q8h AND Piperacillin-tazobactam 3.375 g  IV q6h AND Amikacin 1520 mg/kg IV q24h
- 2.4.Methicillin-resistant Staphylococcus aureus (MRSA):
- Preferred regimen: Vancomycin 1520 mg/kg IV q812 h
- Note: Antimicrobial therapy of established infection should be limited to 47 days, unless it is difficult to achieve adequate source control. Longer durations of therapy have not been associated with improved outcome.
- 3. Community-acquired infection in pediatric patients
- 3.1. Single agent:
- Preferred regimen (1): Ertapenem 3 months to 12 years 15 mg/kg bid (not to exceed 1 g/day) Every 12 h, older than 13 years 1 g/day Every 24 h OR
- Preferred regimen (2): Meropenem 60 mg/kg/day q8h
- Preferred regimen (3): Imipenem-cilastatin 60100 mg/kg/day IV q6h
- Preferred regimen (4): Ticarcillin-clavulanate 200300 mg/kg/day IV of ticarcillin component q46 h
- Preferred regimen (5): Piperacillin-tazobactam 200300 mg/kg/day IV of piperacillin component q68 h
- 3.2.Combination:
- Preferred regimen(1): Ceftriaxone 5075 mg/kg/day q1224 h, AND Metronidazole 3040 mg/kg/day q8h
- Preferred regimen(2): Cefotaxime 150200 mg/kg/day q68 h, AND Metronidazole 3040 mg/kg/day q8h
- Preferred regimen(3): Cefepime 100 mg/kg/day q12h, AND Metronidazole 3040 mg/kg/day q8h
- Preferred regimen(4): Ceftazidime 150 mg/kg/day q8 h, AND Metronidazole 3040 mg/kg/day q8h
- Preferred regimen(5): Gentamicin 37.5 mg/kg/day q24 h, AND Metronidazole 3040 mg/kg/day q8h  Ampicillin 200 mg/kg/day q6h
- Preferred regimen(6): Gentamicin 37.5 mg/kg/day q24 h, AND Clindamycin 2040 mg/kg/day q68 h  Ampicillin 200 mg/kg/day q6h
- Preferred regimen(7): Tobramycin 3.07.5 mg/kg/day q824 h, AND Metronidazole 3040 mg/kg/day q8h  Ampicillin 200 mg/kg/day q6h
- Preferred regimen(8): Tobramycin 3.07.5 mg/kg/day q824 h, AND Clindamycin 2040 mg/kg/day q68 h  Ampicillin 200 mg/kg/day q6h
- Note: Antimicrobial therapy of established infection should be limited to 47 days, unless it is difficult to achieve adequate source control. Longer durations of therapy have not been associated with improved outcome.

# Variceal bleeding, prophylaxis
- 1. Short-term antibiotic prophylaxis
- Preferred regimen (1): Norfloxacin 400mg PO BID for max. of 7 days
- Preferred regimen (2): Ciprofloxacin 400mg IV q12h max. of 7 days (in patients in whom oral administration is not possible)
- 2. In advanced cirrhosis and in a setting with high prevalence of quinolone-resistant organisms
- Preferred regimen: Ceftriaxone 1g IV once daily for max. of 7 days

# Whipple's disease
- 1. Initial Parenteral Therapy
- Preferred regimen: Ceftriaxone 2 g IV daily for 2 weeks
- 2. Long-term Therapy
- Preferred regimen: Trimethoprim-sulfamethoxazole 160/800 mg PO bid for at least 1 year
- Alternative regimen: Doxycycline 100 mg PO bid AND Hydroxychloroquine 200 mg PO tid in cases of allergy or relapse.