Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.
Quick facts
- How it is given
- intramuscular, intravenous
- Type
- human prescription drug
- RxNorm ID
- 1665050
We do not publish dosing. How much of this medicine to take, how often, and for how long depends on your age, weight, kidney and liver function, other conditions and other medicines. That is a decision for the person who prescribes or dispenses it. Follow the directions on your own pack and ask your pharmacist if anything is unclear.
What it is used to treat
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. Cefazolin for Injection, USP is effective in the eradication of streptococci from the nasopharynx; however, data establishing the efficacy of Cefazolin for Injection, USP in the subsequent prevention of rheumatic fever are not available at present. Urinary Tract Infections: Due to E. coli, P. mirabilis, Klebsiella species, and some strains of enterobacter and enterococci. Skin and Skin Structure Infections: Due to S. aureus (penicillin‑sensitive and penicillin-resistant), group A beta‑hemolytic streptococci, and other strains of streptococci. Biliary Tract Infections: Due to E. coli , various strains of streptococci, P. mirabilis , Klebsiella species, and S. aureus . Bone and Joint Infections: Due to S. aureus . Genital Infections: (i.e., prostatitis, epididymitis) due to E. coli , P. mirabilis , Klebsiella species, and some strains of enterococci. Septicemia: Due to S. pneumoniae , S. aureus (penicillin‑sensitive and penicillin‑resistant), P. mirabilis , E. coli , and Klebsiella species. Endocarditis: Due to S. aureus (penicillin‑sensitive and penicillin‑resistant) and group A beta‑hemolytic streptococci. Perioperative Prophylaxis: The prophylactic administration of Cefazolin for Injection preoperatively, intraoperatively, and postoperatively may reduce the incidence of certain postoperative infections in patients undergoing surgical procedures which are classified as contaminated or potentially contaminated (e.g., vaginal hysterectomy, and cholecystectomy in high‑risk patients such as those older than 70 years, with acute cholecystitis, obstructive jaundice, or common duct bile stones). […]
About this medicine
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. Cefazolin for Injection, USP is a sterile white to cream powder supplied in vials. Each vial contains, cefazolin sodium equivalent to 1 gram of cefazolin. The sodium content is approximately 48 mg (2.1 mEq)/1 gram of cefazolin sodium. The color of Cefazolin for Injection, USP solutions may range from pale yellow to yellow without a change in potency. Cefazolin for Injection, USP is to be administered by intramuscular or intravenous routes. Cefazolin structural formula
Who should not take it
CONTRAINDICATIONS CEFAZOLIN FOR INJECTION IS CONTRAINDICATED IN PATIENTS WITH KNOWN ALLERGY TO THE CEPHALOSPORIN GROUP OF ANTIBIOTICS.
Warnings
WARNINGS BEFORE THERAPY WITH CEFAZOLIN FOR INJECTION IS INSTITUTED, CAREFUL INQUIRY SHOULD BE MADE TO DETERMINE WHETHER THE PATIENT HAS HAD PREVIOUS HYPERSENSITIVITY REACTIONS TO CEFAZOLIN, CEPHALOSPORINS, PENICILLINS, OR OTHER DRUGS. IF THIS PRODUCT IS GIVEN TO PENICILLIN‑SENSITIVE PATIENTS, CAUTION SHOULD BE EXERCISED BECAUSE CROSS‑HYPERSENSITIVITY AMONG BETA‑LACTAM ANTIBIOTICS 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 OCCURS, DISCONTINUE TREATMENT WITH THE DRUG. SERIOUS ACUTE HYPERSENSITIVITY REACTIONS MAY REQUIRE TREATMENT WITH EPINEPHRINE AND OTHER EMERGENCY MEASURES, INCLUDING OXYGEN, IV FLUIDS, IV ANTIHISTAMINES, CORTICOSTEROIDS, PRESSOR AMINES, AND AIRWAY MANAGEMENT, AS CLINICALLY INDICATED. Pseudomembranous colitis has been reported with nearly all antibacterial agents, including cefazolin, and may range in severity from mild to life-threatening. Therefore, it is important to consider this diagnosis in patients who present with diarrhea subsequent to the administration of antibacterial agents. Treatment with antibacterial agents alters the normal flora of the colon and may permit overgrowth of clostridia. Studies indicate that a toxin produced by Clostridium difficile is a primary cause of “antibiotic‑associated colitis.” After the diagnosis of pseudomembranous colitis has been established, therapeutic measures should be initiated. Mild cases of pseudomembranous colitis usually respond to drug discontinuation alone. In moderate to severe cases, consideration should be given to management with fluids and electrolytes, protein supplementation, and treatment with an oral antibacterial drug clinically effective against C. difficile colitis.
Reported 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. Hepatic: Transient rise in SGOT, SGPT, and alkaline phosphatase levels has been observed. As with other cephalosporins, reports of hepatitis have been received. Renal: As with other cephalosporins, reports of increased BUN and creatinine levels, as well as renal failure, have been received. Local Reactions: Rare instances of phlebitis have been reported at site of injection. Pain at the site of injection after intramuscular administration has occurred infrequently. Some induration has occurred. Other Reactions: Genital and anal pruritus (including vulvar pruritus, genital moniliasis, and vaginitis). To report SUSPECTED ADVERSE REACTIONS, contact WG Critical Care, LLC at 1-866-562-4708 or FDA at 1-800-FDA-1088 or www.fda.gov .
Interactions with other medicines
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.
Before you take anything new
Tell your pharmacist or doctor about every medicine you take — including ones bought without a prescription, herbal products and supplements. Interactions are one of the most common avoidable causes of harm from medicines, and a pharmacist can check your full list in a couple of minutes.
This page is built from the openFDA record of the U.S. Food and Drug Administration's approved labelling for this product, effective 7 January 2026. Label text has been shortened and reformatted for readability; safety wording has not been altered in meaning. FDA labelling describes products approved in the United States — brand names, strengths, formulations and approved uses may differ in your country. Always read the leaflet that comes with your own pack. PocketsInfo is not affiliated with, and is not endorsed by, the FDA. Retrieved 2026-07-30.