Sandbox ID Musculoskeletal

# Bursitis
- Olecranon bursitis or prepatellar bursitis 
- 1. Staphylococcus aureus, methicillin-susceptible (MSSA)
- Preferred regimen (1): Nafcillin 2 g IV q4h
- Preferred regimen (2): Oxacillin 2 g IV q4h
- Preferred regimen (3): Dicloxacillin 500 mg PO qid
- 2. Staphylococcus aureus, methicillin-resistant (MRSA)
- Preferred regimen (1): Vancomycin 1 g IV q12h
- Preferred regimen (2): Linezolid 600 mg PO qd

# Osteomyelitis, candidal
- Osteomyelitis, candidal 
- Preferred regimen (1): Fluconazole 400 mg/day (6 mg/kg/day) PO for 612 months
- Preferred regimen (2): Amphotericin B 35 mg/kg/day PO for several weeks THEN Fluconazole for 612 months
- Alternative regimen (1): Anidulafungin 200 mg loading dose THEN 100 mg/day PO
- Alternative regimen (2): Caspofungin 70mg loading dose THEN 50 mg/day PO
- Alternative regimen (3): Micafungin 100 mg/day PO
- Alternative regimen (4): Amphotericin B deoxycholate 0.51 mg/kg/day PO for several weeks THEN Fluconazole for 612 months
- Note: Duration of therapy usually is prolonged (612 months); Surgical debridement is frequently necessary

# Osteomyelitis, chronic
- 1. Chronic Osteomyelitis in Adults  Pathogen-Based Therapy 
- 1.1 OSSA
- Preferred regimen (1): Oxacillin 1.52 g IV q4h for 46 weeks
- Preferred regimen (2): Cefazolin 12 g IV q8h for 46 weeks
- Alternative regimen (1): Vancomycin 15 mg/kg IV q12h for 46 weeks
- Alternative regimen (2): Oxacillin 1.52 g IV q4h for 46 weeks AND Rifampin 600 mg PO qd
- 1.2 ORSA
- Preferred regimen (1): Vancomycin 15 mg/kg IV q12h for 46 weeks
- Preferred regimen (2): Daptomycin 6 mg/kg IV q24h
- Alternative regimen (1): Linezolid 600 mg PO/IV q12h for 6 weeks  Rifampin 600900 mg PO qd
- Alternative regimen (2): Levofloxacin 500750 mg/day PO/IV  Rifampin 600900 mg PO qd
- 1.3 Penicillin-sensitive Streptococcus
- Preferred regimen (1): Penicillin G 20 MU/day IV continuously or q4h for 46 weeks
- Preferred regimen (2): Ceftriaxone 12 g IV/IM q24h for 46 weeks
- Preferred regimen (3): Cefazolin 12 g IV q8h for 46 weeks
- Alternative regimen: Vancomycin 15 mg/kg IV q12h for 46 weeks
- 1.4 Enterococcus or Streptococcus (MIC 0.5 g/mL) or Abiotrophia or Granulicatella
- Preferred regimen (1): Penicillin G 20 MU/day IV continuously or q4h for 46 weeks  Gentamicin 1 mg/kg IV/IM q8h for 12 weeks
- Preferred regimen (2): Ampicillin 12 g/day IV continuously or q4h for 46 weeks  Gentamicin 1 mg/kg IV/IM q8h for 12 weeks
- Alternative regimen: Vancomycin 15 mg/kg IV q12h for 46 weeks  Gentamicin 1 mg/kg IV/IM q8h for 12 weeks
- 1.5 Enterobacteriaceae
- Preferred regimen (1): Ceftriaxone 12 g IV/IM q24h for 46 weeks
- Preferred regimen (2): Ertapenem 1 g IV q24h
- Alternative regimen (1): Levofloxacin 500750 mg PO qd
- Alternative regimen (2): Ciprofloxacin 500750 mg PO bid for 46 weeks
- 1.6 Pseudomonas aeruginosa
- Preferred regimen (1): Cefepime 2 g IV q12h
- Preferred regimen (2): Meropenem 1 g IV q8h
- Preferred regimen (3): Imipenem 500 mg IV q6h for 46 weeks
- Alternative regimen (1): Ciprofloxacin 750 mg PO q12h
- Alternative regimen (2): Ceftazidime 2 g IV q8h for 46 weeks
- 2. Chronic Osteomyelitis in Children  Pathogen-Based Therapy
- Group A beta-hemolytic Streptococcus, Haemophilus influenzae type B and Streptococcus pneumoniae
- Preferred regimen (1): Ampicillin 150200 mg/kg/day q6h
- Preferred regimen (2): Amoxicillin 150200 mg/kg/day q6h
- Alternative regimen: Chloramphenicol 75 mg/kg/day q8h

# Osteomyelitis, contiguous with vascular insufficiency
- Osteomyelitis, contiguous with vascular insufficiency 
- Debride overlying ulcer and send bone specimen for histology and culture.
- No empiric antimicrobial therapy unless acutely ill.
- Antibiotic therapy should be based on culture results and treat for 6 weeks.
- Revascularize if possible.

# Osteomyelitis, diabetic foot
- 1. Chronic Infection or Recent Antibiotic Use 
- Preferred regimen (1): Levofloxacin 750 mg IV/PO q24h
- Preferred regimen (2): Cefoxitin 1 g IV q4h (or 2 g IV q68h)
- Preferred regimen (3): Ceftriaxone 12 g/day IV/IM q1224h
- Preferred regimen (4): Ampicillin-Sulbactam 1.53 g IV/IM q6h
- Preferred regimen (5): Moxifloxacin 400 mg IV/PO q24h
- Preferred regimen (6): Ertapenem 1 g IV/IM q24h
- Preferred regimen (7): Tigecycline 100 mg IV THEN 50 mg IV q12h (active against MRSA)
- Preferred regimen (8): Imipenem-Cilastatin 0.51 g IV q68h (Not active against MRSA; consider when ESBL-producing pathogens suspected)
- Alternative regimen (1): Levofloxacin 750 mg IV/PO q24h AND Clindamycin 150300 mg PO qid
- Alternative regimen (2): Ciprofloxacin 6001200 mg/day IV q612h AND Clindamycin 150300 mg PO qid
- Alternative regimen (3): Ciprofloxacin 12002700 mg IV q612h (for more severe cases) AND Clindamycin 150300 mg PO qid
- 2. High Risk for MRSA
- Preferred regimen (1): Linezolid 600 mg IV/PO q12h
- Preferred regimen (2): Daptomycin 4 mg/kg IV q24h
- Preferred regimen (3): Vancomycin 1520 mg/kg IV q812h (trough: 1020 mg/L)
- 3. High Risk for Pseudomonas aeruginosa
- Preferred regimen: PiperacillinTazobactam 3.375 g IV q68h
- 4. Polymicrobial Infection
- Preferred regimen: (Vancomycin 1520 mg/kg IV q812h (trough: 1020 mg/L) OR Linezolid 600 mg IV/PO q12h OR Daptomycin 4 mg/kg IV q24h) AND (PiperacillinTazobactam 3.375 g IV q68h OR ImipenemCilastatin 0.51 g IV q68h OR Ertapenem 1 g IV/IM q24h OR Meropenem 1 g IV q8h)
- Alternative regimen: (Vancomycin 1520 mg/kg IV q812h (trough: 1020 mg/L) OR Linezolid 600 mg IV/PO q12h OR Daptomycin 4 mg/kg IV q24h) AND (Ceftazidime 2 g IV q8h OR Cefepime 2 g IV q8h OR Aztreonam 2 g IV q68h) AND Metronidazole 15 mg/kg IV, then 7.5 mg/kg IV q6h

# Osteomyelitis, foot bone
- Foot bone osteomyelitis due to nail through tennis shoe 
- Preferred regimen (1): Ciprofloxacin 750 mg PO bid
- Preferred regimen (2): Levofloxacin 750 mg PO q24h
- Alternative regimen (1): Ceftazidime 2 g IV q8h
- Alternative regimen (2): Cefepime 2 g IV q12h

# Osteomyelitis, foot puncture wound
- Long bone, post-internal fixation of fracture 
- 1. S. aureus  or  P. aeruginosa
- Preferred regimen: Vancomycin 1 g IV q12h AND (Ceftazidime OR Cefepime)
- Alternative regimen (1): Linezolid 600 mg IV/PO bidNAI AND Ceftazidime
- Alternative regimen (2): Linezolid 600 mg IV/PO bidNAI AND Cefepime
- 2. Gm-neg. bacilli
- Preferred regimen (1): Ciprofloxacin 750 mg po bid
- Preferred regimen (2): Levofloxacin 750 mg po qd

# Osteomyelitis, hematogenous
- 1. Empiric therapy 
- 1.1 Adult (>21 yrs)
- 1.1.1 MRSA possible
- Preferred regimen: Vancomycin 1 g IV q12h (if over 100 kg, 1.5 g IV q12h)
- 1.1.2 MRSA unlikely
- Preferred regimen: Nafcillin OR Oxacillin 2 g IV q4h
- 1.2 Children (>4 mos.)-Adult
- 1.2.1 MRSA possible
- Preferred regimen: Vancomycin 40 div q68h
- 1.2.2 MRSA unlikely
- Preferred regimen: Nafcillin OR Oxacillin 37 q6h (to max. 812 g per day)
- Note: Add Ceftazidime 50 q8h or Cefepime 150 div q8h if Gm-neg. bacilli on Gram stain
- 1.3 Newborn (<4 mos.)
- 1.3.1 MRSA possible
- Preferred regimen: Vancomycin AND (Ceftazidime 2 g IV q8h or Cefepime 2 g IV q12h)
- 1.3.2 MRSA unlikely
- Preferred regimen: (Nafcillin OR Oxacillin) AND (Ceftazidime OR Cefepime)
- 2. Specific therapy
- 2.1 MSSA
- Preferred regimen: Nafcillin OR Oxacillin 2 g IV q4h OR Cefazolin 2 g IV q8h
- Alternative regimen: Vancomycin 1 g IV q12h (if over 100 kg, 1.5 g IV q12h)
- 2.2 MRSA
- Preferred regimen: Vancomycin 1 g IV q12h
- Alternative regimen: Linezolid 600 mg q12h IV/po  Rifampin 300 mg po/IV bid

# Osteomyelitis, hemoglobinopathy
- Osteomyelitis, hemoglobinopathy 
- Preferred regimen: Ciprofloxacin 400 mg IV q12h
- Alternative regimen: Levofloxacin 750 mg IV q24h

# Osteomyelitis, spinal implant
- 1. Onset within 30 days  
- Culture, treat & then suppress until fusion occurs
- Main parenteral antimicrobial therapy
- Preferred regimen: Beta-lactam antibiotic OR Vancomycin
- Suppressive antimicrobial therapy strategy
- Preferred regimen: Beta-lactam antibiotic OR Minocycline
- 2. Onset after 30 days
- Remove implant, culture & treat
- Main parenteral antimicrobial therapy
- Preferred regimen: Beta-lactam antibiotic OR Vancomycin OR Combination therapy
- Suppressive antimicrobial therapy strategy
- Preferred regimen: Combination therapy OR Minocycline

# Osteomyelitis, vertebral
- Vertebral Osteomyelitis  Pathogen-Based Therapy  
- 1. OSSA or coagulase-negative staphylococci
- Preferred regimen (1): Oxacillin 2 g IV q6h
- Preferred regimen (2): Cefazolin 12 g IV q8h
- Alternative regimen: Levofloxacin 750 mg PO qd AND Rifampin 300 mg PO bid
- 2. ORSA
- Preferred regimen: Vancomycin 1 g IV q12h
- Alternative regimen (1): Daptomycin 6 mg/kg IV q24h
- Alternative regimen (2): Levofloxacin 500750 mg/day PO/IV AND Rifampin 600900 mg PO qd
- 3. Streptococcus
- Preferred regimen: Penicillin G 5 MU IV q6h
- Alternative regimen: Ceftriaxone 2 g IV q24h
- 4. Enterobacteriaceae, quinolone-susceptible
- Preferred regimen: Ciprofloxacin 750 mg PO q12h
- Alternative regimen: Ceftriaxone 2 g IV q24h
- 5. Enterobacteriaceae, quinolone-resistant
- Preferred regimen: Imipenem 500 mg IV q6h
- 6. Pseudomonas aeruginosa
- Preferred regimen: (Cefepime 2 g IV q8h OR Ceftazidime 2 g IV q8h for 24 weeks), followed by Ciprofloxacin 750 mg PO bid
- Alternative regimen: PiperacillinTazobactam 750 mg PO q12h for 24 weeks, followed by Ciprofloxacin 750 mg PO bid
- 7. Anaerobes
- Preferred regimen: PiperacillinTazobactam 750 mg PO q12h for 24 weeks, followed by Ciprofloxacin 750 mg PO bid
- Alternative regimen (1): Penicillin G 5 MU IV q6h
- Alternative regimen (2): Ceftriaxone 2 g IV q24h (against gram-positive anaerobes)
- Alternative regimen (3): Metronidazole 500 mg PO tid (against gram-negative anaerobes)

# Osteomyelitis, sternal
- Osteomyelitis, sternal 
- Preferred regimen: Vancomycin 1 g IV q12h (If over 100kg, 1.5 g IV q12h)
- Alternative regimen:  Linezolid 600 mg po/IVNAI bid

# Osteonecrosis of the jaw
- 1. Bacterial Infection 
- Preferred regimen (1): Penicillin VK 500 mg PO q68h for 710 days (maintenance: 500 mg PO bid)
- Preferred regimen (2): Amoxicillin 500 mg PO q8h for 710 days (maintenance: 500 mg PO bid)
- Alternative regimen (1): Clindamycin 150300 mg PO qid
- Alternative regimen (2): Doxycycline 100 mg PO qd
- Alternative regimen (3): Erythromycin 400 mg PO tid
- Alternative regimen (4): Azithromycin 500 mg PO single dose THEN 250 mg PO qd for 4 days
- Alternative regimen (5): Levofloxacin 500 mg PO qd
- Alternative regimen (6): Moxifloxacin 400 mg PO qd
- 2. Fungal Infection
- Preferred regimen (1): Nystatin oral suspension 515 mL swish qid
- Preferred regimen (2): Fluconazole 200 mg PO qd THEN 100 mg q24h
- Preferred regimen (3): Clotrimazole 10 mg PO tid for 710 days
- 3. Viral Infection
- Preferred regimen (1): Acyclovir 400 mg PO bid
- Preferred regimen (2): Valacyclovir 0.52.0 g PO bid

# Reactive arthritis, post-streptococcal  arthritis
- Reactive arthritis, post-streptococcal  arthritis 
- Treat strep pharyngitis and then NSAIDs (Prednisone needed in some patients)

# Reactive arthritis, Reiter's  syndrome
- Reactive arthritis, Reiter's  syndrome 
- Only treatment is non-steroidal anti-inflammatory drugs

# Septic arthritis, Brucella melitensis
- Septic arthritis, Brucella melitensis 
- Preferred Regimen: Doxycycline 100 mg PO bid for  6 weeks AND Streptomycin 15 mg/kg IM qd for 23 weeks OR Rifampin 600900 mg qd for  6 weeks
- Alternative Regimen: Doxycycline 100 mg PO bid for  6 weeks AND Gentamicin 5 mg/kg IV qd for 7 days

# Septic arthritis, candidal
- Septic arthritis, candidal 
- Preferred regimen (1): Fluconazole 400 mg/day (6 mg/kg/day) for at least 6 weeks
- Preferred regimen (2): Amphotericin B 35 mg/kg/day for several weeks THEN Fluconazole to completion
- Alternative regimen (1): Anidulafungin 200-mg loading dose THEN 100 mg/day
- Alternative regimen (2): Caspofungin 70-mg loading dose THEN 50 mg/day
- Alternative regimen (3): Micafungin 100 mg/day
- Alternative regimen (4): Amphotericin B deoxycholate 0.51 mg/kg/day for several weeks THEN Fluconazole to completion
- Note: Duration of therapy usually is for at least 6 weeks, but few data are available; Surgical debridement is recommended for all cases; For infected prosthetic joints, removal is recommended for most cases.

# Septic arthritis, gonococcal
- Septic arthritis, gonococcal 
- Preferred regimen: Ceftriaxone 1 g intramuscularly IM/IV q24h
- Alternative regimen (1): Cefotaxime 1 g IV q8h
- Alternative regimen (2): Ceftizoxime 1 g IV q8h
- Alternative regimen (3): Spectinomycin 2 g IV q12h (Penicillin allergies)
- Alternative regimen (4): Ciprofloxacin 500 mg IV q12h OR Ofloxacin 400 mg IV q12h (-lactam-allergic patient)
- Note: The tetracyclines (except in pregnant women) or penicillins may be used if the infecting organism is proven to be susceptible
- Pediatric regimen:
- >45 kg
- Preferred regimen: Ceftriaxone 50 mg/kg (Maximum, 2 g/dose) IM/IV single dose for 10 to 14 days
- <45 kg
- Preferred regimen: Ceftriaxone 50 mg/kg (Maximum, 1 g/dose) IM/IV single dose for 7 days

# Septic arthritis, Gram-negative  bacilli
- Septic arthritis, Gram-negative  bacilli 
- Preferred regimen (1): Ceftazidime 2 g IV q8h
- Preferred regimen (2): Cefepime 2 g IV q812h
- Preferred regimen (3): Piperacillin-Tazobactam 4.5 g IV q6h
- Alternative regimen (1): Aztreonam 2 g IV q8h
- Alternative regimen (2): Imipenem 500 mg IV q6h
- Alternative regimen (3): Meropenem 1 g IV q8h
- Alternative regimen (4): Doripenem 500 mg IV q8h
- Alternative regimen (5): Carbapenems

# Septic arthritis, Histoplasmosis
- Septic arthritis, histoplasmosis
- 1. Mild disease
- Preferred regimen: Nonsteroidal anti-inflammatory drug
- 2. Severe disease
- Preferred regimen: Prednisone 0.51.0 mg/kg/day (Maximum, 80 mg/day) in tapering doses over 12 weeks AND Itraconazole 200 mg tid for 3 days, followed by qd or bid for 612 weeks

# Septic arthritis, Lyme disease
- Septic arthritis, Lyme disease 
- 1. Patients without clinical evidence of neurologic disease
- Preferred regimen (1): Doxycycline 100 mg bid for 28 days
- Preferred regimen (2): Amoxicillin 500 mg tid for 28 days
- Preferred regimen (3): Cefuroxime axetil 500 mg bid for 28 days
- Pediatric regimen (1): Amoxicillin 50 mg/kg/day tid (Maximum, 500 mg/dose)
- Pediatric regimen (2): Cefuroxime axetil 30 mg/kg/day bid (Maximum, 500 mg/dose)
- Pediatric regimen (3): (if the patient is 8 years of age) Doxycycline 4 mg/kg/day bid (Maximum, 100 mg/dose)
- 2. Patients with arthritis and objective evidence of neurologic disease
- Preferred regimen: Ceftriaxone administered parenterally for 24 weeks
- Alternative regimen: Cefotaxime OR Penicillin G administered parenterally
- Pediatric regimen: Ceftriaxone OR Cefotaxime OR Penicillin G administered intravenously
- Note (1): For patients who have persistent or recurrent joint swelling after a recommended course of oral antibiotic therapy, we recommend re-treatment with another 4-week course of oral antibiotics or with a 24-week course of Ceftriaxone IV
- Note (2): If patients have no resolution of arthritis despite intravenous therapy and if PCR results for a sample of synovial fluid (and synovial tissue if available) are negative, symptomatic treatment is recommended, which consist of nonsteroidal anti-inflammatory agents, intra-articular injections of corticosteroids, or disease-modifying antirheumatic drugs (DMARDs), such as Hydroxychloroquine.

# Septic arthritis, Mycobacterium  tuberculosis
- Septic arthritis, Mycobacterium  tuberculosis
- 1. Septic arthritis caused by susceptible Mycobacterium tuberculosis
- 1.1 Adults
- 1.1.1 Intensive phase
- Preferred regimen: Isoniazid 5 mg/kg (max, 300 mg) for 2 months AND Rifampin 10 mg/kg (max: 600 mg) for 2 months AND Pyrazinamide 1530 mg/kg (max: 2 g) for 2 months AND Ethambutol 1520 mg/kg (max: 1 g) for 2 months
- 1.1.2 Continuation phase
- Preferred regimen: Isoniazid 5 mg/kg (max: 300 mg) for 7 months AND Rifampin 10 mg/kg (max: 600 mg) for 7 months
- 1.2 Pediatric
- 1.2.1 Intensive phase
- Preferred regimen: Isoniazid 1015 mg/kg (max: 300 mg) for 2 months AND Rifampin 1020 mg/kg (max: 600 mg) for 2 months AND Pyrazinamide 1530 mg/kg (max: 2 g) for 2 months AND Ethambutol 1520 mg/kg (max: 1 g) for 2 months
- 1.2.2 Continuation phase
- Preferred regimen: Isoniazid 1015 mg/kg (max: 300 mg) for 7 months AND Rifampin 1020 mg/kg (max: 600 mg) for 7 months
- 2. Specific considerations
- 2.1 Pregnancy and breastfeeding
- With the exception of streptomycin, the first line anti-TB drugs are safe for use in pregnancy: Streptomycin is ototoxic to the fetus and should not be used during pregnancy.
- After active TB in the baby is ruled out, the baby should be given 6 months of isoniazid preventive therapy, followed by BCG vaccination.
- Pyridoxine supplementation is recommended for all pregnant or breastfeeding women taking isoniazid.
- 2.2 Liver disorders
- Two hepatotoxic drugs (rather than the three in the standard regimen):
- 9 months of Isoniazid AND Rifampicin AND Ethambutol (until or unless Isoniazid susceptibility is documented).
- 2 months of Isoniazid AND Rifampicin AND Streptomycin AND Ethambutol, followed by 6 months of Isoniazid AND Rifampicin.
- 69 months of Rifampicin AND Pyrazinamide AND Ethambutol
- One hepatotoxic drug:
- 2 months of Isoniazid AND Ethambutol AND Streptomycin, followed by 10 months of Isoniazid AND Ethambutol
- No hepatotoxic drugs:
- 1824 months of Streptomycin AND Ethambutol AND a Fluoroquinolone
- 2.3 Renal failure and severe renal insufficiency
- The recommended initial TB treatment regimen for patients with renal failure or severe renal insufficiency is 2 months of isoniazid, rifampicin, pyrazinamide and ethambutol, followed by 4 months of isoniazid and rifampicin.
- There is significant renal excretion of ethambutol and metabolites of pyrazinamide, and doses should therefore be adjusted.
- Three times per week administration of these two drugs at the following doses is recommended: pyrazinamide (25 mg/kg), and ethambutol (15 mg/kg)
- While receiving isoniazid, patients with severe renal insufficiency or failure should also be given pyridoxine in order to prevent peripheral neuropathy.
- Because of an increased risk of nephrotoxicity and ototoxicity, Streptomycin should be avoided in patients with renal failure. If Streptomycin must be used, the dosage is 15 mg/kg, two or three times per week, to a maximum of 1 gram per dose, and serum levels of the drug should be monitored.
- 2.4 Previously treated patients in settings with rapid DST
- TB patients whose treatment has failed or other patient groups with high likelihood of multidrug-resistant TB (MDR) should be started on an empirical MDR regimen.
- TB patients returning after defaulting or relapsing from their first treatment course may receive the retreatment regimen containing first-line drugs 2HRZES/1HRZE/5HRE if country-specific data show low or medium levels of MDR in these patients or if such data are not available.
- 2.5 TB treatment in people living with HIV
- TB patients with known positive HIV status and all TB patients living in HIV prevalent settings should receive daily TB treatment at least during the intensive phase.
- For the continuation phase, the optimal dosing frequency is also daily for these patients.
- If a daily continuation phase is not possible for these patients, three times weekly dosing during the continuation phase is an acceptable alternative.
- It is recommended that TB patients who are living with HIV should receive at least the same duration of TB treatment as HIV-negative TB patients.

# Septic arthritis, pneumococcal

# Septic arthritis, post-intraarticular injection
- Septic arthritis, post-intraarticular injection 
- NO empiric therapy.

# Septic arthritis, prosthetic joint infection
- Septic arthritis, prosthetic joint infection (device-related osteoarticular infections) 
- 1. Empiric antimicrobial therapy
- It is preferable to delay antibiotic therapy until specimens for culture are obtained by joint aspiration, joint debridement, and/or prosthesis removal.
- 2. Pathogen-directed antimicrobial therapy
- 2.1 Staphylococcus aureus, methicillin-susceptible (MSSA)
- Preferred regimen (1): Nafcillin 2 g IV q46h
- Preferred regimen (2): Oxacillin 2 g IV q46h
- Alternative regimen (1): Cefazolin 12 g IV q8h
- Alternative regimen (2): Ceftriaxone 2 g IV q24h
- Alternative regimen (3): (if allergic to penicillins) Clindamycin 900 mg IV q8h
- Alternative regimen (4): (if allergic to penicillins) Vancomycin 1520 mg/kg IV q812h (Maximum, 2 g/dose)
- 2.2 Staphylococcus, methicillin-resistant (MRSA)
- 2.2.1 Early-onset or acute hematogenous prosthetic joint infections involving a stable implant with short duration (< 3 weeks) of symptoms and debridement (but device retention)
- Preferred regimen: Vancomycin AND Rifampin 600 mg PO qd or 300450 mg PO bid for 2 weeks
- Alternative regimen: (Daptomycin 6 mg/kg IV q24h OR Linezolid 600 IV q8h) AND Rifampin 600 mg PO qd or 300450 mg PO bid for 2 weeks
- Note: The above regimen should be followed by Rifampin plus a fluoroquinolone, TMP/SMX, a tetracycline or Clindamycin for 3 or 6 months for hips and knees, respectively.
- 2.2.2 Early-onset spinal implant infections or implants in an actively infected site
- Initial parenteral therapy plus Rifampin followed by prolonged oral therapy is recommended.
- Long-term oral suppressive antibiotics (eg, TMP-SMX, a tetracycline, a fluoroquinolone [which should be given in conjunction with Rifampin due to the potential emergence of fluoroquinolone resistance)
- 2.3 Streptococci, beta-hemolytic
- Preferred regimen (1): Penicillin 1218 MU/day IV q6h
- Preferred regimen (2): Ampicillin 2 g IV q6h
- Preferred regimen (3): Ceftriaxone 12 g IV q24h
- Alternative regimen (1): (if allergic to penicillins) Clindamycin 900 mg IV q8h
- Alternative regimen (2): (if allergic to penicillins) Vancomycin 1520 mg/kg IV q812h (Maximum, 2 g/dose)
- 2.4 Enterococci
- 2.4.1 Monotherapy
- Preferred regimen (1): Ampicillin 6-12 g/day q4-6h
- Preferred regimen (2): Penicillin G 18-30 MU/day continuously or q4h
- Preferred regimen (3): Vancomycin 15-20 mg/kg/dose q8-12h (Maximum, 2 g/dose)
- 2.4.2 Combination therapy (one of the monotherapy agents, and one of the following agents)
- Preferred regimen (1): Gentamicin 1 mg/kg IV q8h
- Preferred regimen (2): Streptomycin 7.5 mg/kg IV q12h
- Preferred regimen (3): Ampicillin 2 g/day IV q6h AND Ceftriaxone 2 g IV q12h
- 2.5 Gram-negative bacilli
- Patients susceptible to fluoroquinolones
- Preferred regimen: Ciprofloxacin 500-750 mg bid
- 2.5.1 P. aeruginosa
- Preferred regimen (1): Cefepime 2 g IV q12h
- Preferred regimen (2): Meropenem 1 g IV q8h
- Alternative regimen (1): Ciprofloxacin 750 mg PO bid
- Alternative regimen (2): Ceftazidime 2 g IV q8h
- 2.6 Anaerobes
- 2.6.1Propionibacterium acnes
- Preferred regimen (1): Penicillin 24 MU/day IV q4h or continuously
- Preferred regimen (2): Ceftriaxone 1-2 g/day IV
- Alternative regimen: Vancomycin OR Clindamycin
- 2.6.2 Not Propionibacterium acnes
- Preferred regimen: Metronidazole 500 mg PO tid
- 2.7 Mycobacterium tuberculosis
- Preferred regimen: see (Septic arthritis, Mycobacterium tuberculosis)
- 2.8 Fungi
- Preferred regimen: see (Septic arthritis, candidal)
- 2.9 Culture negative
- Preferred regimen:  Vancomycin AND Ciprofloxacin OR Cefazolin AND Ciprofloxacin

# Septic arthritis, staphylococcal
- 1.Staphylococcus aureus (methicillin-resistant)
- Preferred regime: Vancomycin 1520 mg/kg IV q812h
- Alternative regimen (1): Daptomycin 6 mg/kg IV q24h
- Alternative regimen (2): Linezolid 600 mg PO/IV q12h
- Alternative regimen (3): Clindamycin 600 mg PO/IV q8h
- Alternative regimen (4): TMP-SMX 3.54.0 mg/kg PO/IV q812h
- Pediatric regimen(1): Vancomycin 15 mg/kg IV q6h
- Pediatric regimen(1): Daptomycin 610 mg/kg IV q24h
- Pediatric regimen(1): Linezolid 10 mg/kg PO/IV q8h
- Pediatric regimen(1): Clindamycin 1013 mg/kg/dose PO/IV q68h
2. Staphylococcus aureus (methicillin-susceptible)
- Preferred regimen (1): Nafcillin 2 g IV q6h
- Preferred regimen (2): Clindamycin 900 mg IV q8h
- Alternative regimen (1): Cefazolin 0.251 g IV/IM q68h
- Alternative regimen (2): Vancomycin 500 mg IV q6h or 1 g IV q12h
3. Staphylococcus epidermidis (methicillin-resistant)
- Preferred regimen (1): Vancomycin 500 mg IV q6h or 1 g IV q12h
- Preferred regimen (2): Linezolid 600 mg IV q12h
- Alternative regimen: (TMP-SMX 3.54.0 mg/kg PO/IV q812h (TMP component) OR Minocycline 200 mg PO single dose THEN 100 mg PO q12h) AND Rifampin 300600 mg PO/IV q12h
4. Staphylococcus epidermidis (methicillin-susceptible)
- Preferred regimen (1): Nafcillin 2 g IV q6h
- Preferred regimen (2): Clindamycin 900 mg IV q8h
- Alternative regimen (1): Cefazolin 0.251 g IV/IM q68h
- Alternative regimen (2): Vancomycin 500 mg IV q6h or 1 g IV q12h

# Septic arthritis, streptococcal
1. Streptococcus agalactiae 
- Preferred regimen (1): Penicillin G 2 MU IV/IM q4h
- Preferred regimen (2): Ampicillin 2 g IV q6h
- Alternative regimen (1): Clindamycin 6001200 mg/day IV/IM q612h
- Alternative regimen (2): Cefazolin 0.251 g IV/IM q68h
2. Streptococcus pyogenes
- Preferred regimen (1): Penicillin G 2 MU IV/IM q4h
- Preferred regimen (2): Ampicillin 2 g IV q6h
- Alternative regimen (1): Clindamycin 6001200 mg/day IV/IM q612h
- Alternative regimen (2): Cefazolin 0.251 g IV/IM q68h