Doripenem warnings and precautions

# Warnings and Precautions

## Hypersensitivity Reactions
Serious and occasionally fatal hypersensitivity (anaphylactic) and serious skin reactions have been reported in patients receiving beta-lactam antibiotics. These reactions are more likely to occur in individuals with a history of sensitivity to multiple allergens. Before therapy with DORIBAX is instituted, careful inquiry should be made to determine whether the patient has had a previous hypersensitivity reaction to other carbapenems, cephalosporins, penicillins or other allergens. If this product is to be given to apenicillin- or other beta-lactam-allergic patient, caution should be exercised because cross-reactivity among beta-lactam antibiotics has been clearly documented.
If an allergic reaction to DORIBAX occurs, discontinue the drug. Serious acute hypersensitivity (anaphylactic) reactions require emergency treatment, as clinically indicated.

## Seizures
Seizures have been reported during treatment with doripenem (see section 6.2). In clinical trials, doripenem-treated patients with pre-existing central nervous system (CNS) disorders (e.g. stroke or history of seizures), patients with compromised renal function and patients given doses greater than 500 mg every 8 hours appear to be at greater risk for developing seizures.

## Interaction with Valproic Acid
Due to a drug interaction, patients with seizure disorders controlled with valproic acid or sodium valproate will be at an increased risk for breakthrough seizures when treated with DORIBAX concomitantly. Reduction in serum valproic acid concentrations to below the therapeutic concentration range (50 to 100 mcg/mL) was observed by 12 hours after the initiation of doripenem in healthy subjects co-administered both drugs. A similar drug interaction involving other carbapenem antibacterials and valproic acid has been described in published case reports. In some of these reports, increasing the dose of valproic acid or sodium valproate did not result in increased valproic acid serum concentrations. Alternative antibacterial therapies should be considered for patients receiving valproic acid or sodium valproate. If administration of DORIBAX is necessary, supplemental anti-convulsant therapy should be considered. 

## Clostridium difficile-Associated Diarrhea
Clostridium difficile-associated diarrhea (CDAD) has been reported with nearly all antibacterial agents and may range in severity from mild diarrhea to fatal colitis.
Treatment with antibacterial agents alters the normal flora of the colon and may permit overgrowth of C. difficile.
C. difficile produces toxins A and B which contribute to the development of CDAD. Hypertoxin producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibiotic use. Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents.
If CDAD is suspected or confirmed, ongoing antibiotic use not directed against C. difficile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile, and surgical evaluation should be instituted as clinically indicated. 

## Development of Drug-Resistant Bacteria
Prescribing DORIBAX in the absence of a proven or strongly suspected bacterial infection is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.

## Pneumonitis with Inhalational Use
When DORIBAX has been used investigationally via inhalation, pneumonitis has occurred. DORIBAX should not be administered by this route.