Overview
DESCRIPTION Cefazolin for Injection, USP is a semi-synthetic cephalosporin for parenteral administration. It is the sodium salt of 3-{[(5-methyl-1,3,4-thiadiazol-2-yl)thio]-methyl}-8-oxo-7-[2-(1H-tetrazol-1-yl) acetamido]-5-thia-1-azabicyclo [4.2.0]oct-2-ene-2-carboxylic acid. Structural Formula: C 14 H 13 N 8 NaO 4 S 3 M.W. 476.5 The pH of the reconstituted solution is between 4 and 6.
Mechanism of Action
CLINICAL PHARMACOLOGY After intramuscular administration of Cefazolin for Injection to normal volunteers, the mean serum concentrations were 37 mcg/mL at 1 hour and 3 mcg/mL at 8 hours following a 500‑mg dose, and 64 mcg/mL at 1 hour and 7 mcg/mL at 8 hours following a 1‑gram dose. Studies have shown that following intravenous administration of Cefazolin for Injection to normal volunteers, mean serum concentrations peaked at approximately 185 mcg/mL and were approximately 4 mcg/mL at 8 hours for a 1‑gram dose. The serum half‑life for Cefazolin for Injection is approximately 1.8 hours following I.V. administration and approximately 2 hours following I.M. administration. In a study (using normal volunteers) of constant intravenous infusion with dosages of 3.
Indications
- INDICATIONS AND USAGE Cefazolin for Injection, USP is indicated for the treatment of the following serious infections when due to susceptible organisms. Respiratory Tract Infections: Due to S. pneumoniae, Klebsiella species , H. influenzae, S. aureus (penicillin-sensitive and penicillin-resistant), and group A beta-hemolytic streptococci. Injectable benzathine penicillin is considered the drug of choice in treatment and prevention of streptococcal infections, including the prophylaxis of rheumatic fever.
Common Doses
- 500 mg
- 250 mg
- 55 mL
- 1.5 mg
Dosage
DOSAGE AND ADMINISTRATION Usual Adult Dosage: Type of Infection Dose Frequency Moderate to severe infections 500 mg to 1 gram every 6 to 8 hours Mild infections caused by susceptible gram-positive cocci 250 mg to 500 mg every 8 hours Acute, uncomplicated urinary tract infections 1 gram every 12 hours Pneumococcal pneumonia 500 mg every 12 hours Severe, life-threatening infections (e.g., endocarditis, septicemia)* 1 gram to 1.5 grams every 6 hours * In rare instances, doses of up to 12 grams of Cefazolin for Injection per day have been used.
Contraindications
- CONTRAINDICATIONS CEFAZOLIN FOR INJECTION IS CONTRAINDICATED IN PATIENTS WITH KNOWN ALLERGY TO THE CEPHALOSPORIN GROUP OF ANTIBIOTICS.
Side Effects
- ADVERSE REACTIONS The following reactions have been reported: Gastrointestinal: Diarrhea, oral candidiasis (oral thrush), vomiting, nausea, stomach cramps, anorexia, and pseudomembranous colitis. Onset of pseudomembranous colitis symptoms may occur during or after antibiotic treatment (see WARNINGS). Nausea and vomiting have been reported rarely. Allergic: Anaphylaxis, eosinophilia, itching, drug fever, skin rash, Stevens‑Johnson syndrome. Hematologic: Neutropenia, leukopenia, thrombocytopenia, thrombocythemia.
Interactions
- Drug Interactions Probenecid may decrease renal tubular secretion of cephalosporins when used concurrently, resulting in increased and more prolonged cephalosporin blood levels. Drug/Laboratory Test Interactions A false positive reaction for glucose in the urine may occur with Benedict’s solution, Fehling’s solution or with CLINITEST ® tablets, but not with enzyme-based tests such as CLINISTIX ® . Positive direct and indirect antiglobulin (Coombs) tests have occurred; these may also occur in neonates whose mothers received cephalosporins before delivery.