Cefazolin sodium warnings and precautions

# Warnings and Precautions

## Hypersensitivity Reactions to Cefazolin, Cephalosporins, Penicillins, or Other Beta-lactams
Serious and occasionally fatal hypersensitivity (anaphylactic) reactions have been reported in patients receiving beta-lactam antibacterial drugs. Before therapy with Cefazolin for Injection, USP is instituted, careful inquiry should be made to determine whether the patient has had previous immediate hypersensitivity reactions to cefazolin, cephalosporins, penicillins, or carbapenems. Exercise caution if this product is to be given to penicillin-sensitive patients because cross-hypersensitivity among beta-lactam antibacterial drugs has been clearly documented and may occur in up to 10% of patients with a history of penicillin allergy. If an allergic reaction to Cefazolin for Injection, USP occurs, discontinue the drug.

## Use in Patients with Renal Impairment
This formulation of Cefazolin for Injection USP  Pharmacy Bulk Package bags SmartPak should not be used in renally impaired patients who require less than the 1 gram dose of cefazolin.
As with other beta-lactam antibacterial drugs, seizures may occur if inappropriately high doses are administered to patients with impaired renal function (creatinine clearance less than 55 mL/minute) .

## Clostridium difficile-associated Diarrhea
Clostridium difficile associated diarrhea (CDAD) has been reported with the use of nearly all antibacterial agents, including cefazolin and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile.
C. difficile produces toxins A and B, which contribute to the development of CDAD. Hypertoxin- producing isolates 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 antibacterial drug 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 antibacterial drug use not directed against C. difficile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibacterial drug treatment of C. difficile, and surgical evaluation should be instituted as clinically indicated.

## Risk of Developing Drug-resistant Bacteria
Prescribing Cefazolin for Injection, USP in the absence of proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.
As with other antimicrobials, prolonged use of Cefazolin for Injection, USP may result in overgrowth of nonsusceptible microorganisms. Repeated evaluation of the patient's condition is essential. Should superinfection occur during therapy, appropriate measures should be taken.

## Drug/Laboratory Test Interactions

### Urinary Glucose
The administration of cefazolin may result in a false-positive reaction with glucose in the urine when using CLINITEST tablets. It is recommended that glucose tests based on enzymatic glucose oxidase reactions (e.g., CLINISTIX) be used.

### Coombs' Test
Positive direct Coombs tests have been reported during treatment with cefazolin, In hematologic studies or in transfusion-cross-matching procedures when antiglobulin tests are performed on the minor side or in Coombs' testing of newborns whose mothers have received cephalosporin antibacterial drugs before parturition, it should be recognized that a positive Coombs' test may be due to the drug.