Cefazolin is a first-generation cephalosporin antibiotic used to treat bacterial infections of the skin, respiratory tract, urinary tract, bones, and joints.
It is also widely administered before and during surgery to prevent postoperative infections.
It works by destroying bacteria cell walls and is given via injection.
Surgical Prophylaxis: Given prior to surgeries to prevent surgical site infections.
Bacterial Infections: Treats conditions such as cellulitis, pneumonia, urinary tract infections, and endocarditis.
Spectrum: Highly effective against Gram-positive bacteria (like Staphylococcus and Streptococcus), but has limited effectiveness against Gram-negative bacteria.
Some gram-negatives (E. coli, Klebsiella, Proteus mirabilis).
Poor anaerobic coverage.
Administration
Delivery: as an intravenous (IV) infusion or an intramuscular (IM) injection.
Schedule: Depending on the severity of the infection, it is typically administered every 6, 8, or 12 hours.
Penicillin Allergies: Often used as a safe alternative for patients with penicillin allergies.
However, people with a history of severe, immediate allergic reactions to penicillin should be cautious of it use.
Kidney Function: Because the kidneys primarily excrete cefazolin, dosage adjustments may be required for patients with renal impairment.
Common Side Effects:
Some patients may experience mild side effects, which include:
Nausea, vomiting, or diarrhea Stomach cramps or loss of appetite Pain or swelling at the injection site.
Common uses
Surgical prophylaxis-the most common antibiotic used perioperatively.
Skin and soft tissue infections (cellulitis, wound infections)
Uncomplicated UTIs
Bone and joint infections (MSSA osteomyelitis)
Endocarditis (MSSA, in penicillin-allergic patients)
Step-down or outpatient IV therapy via PICC line
Dosing
1–2 g IV/IM q8h for most infections 2 g IV 30–60 min before surgical incision for prophylaxis Renal dose adjustment required (reduce dose or extend interval if CrCl < 35 mL/min)
Not orally bioavailable — IV or IM only Half-life ~1.8 hours (longer in renal impairment) Primarily renally excreted unchanged
-Drug of choice for MSSA bacteremia and surgical prophylaxis
Safe in most penicillin allergies (cross-reactivity is ~1–2%, mainly with anaphylaxis history)
Does *not* penetrate the CNS well — not used for meningitis
Pregnancy category B — generally considered safe
In patients with methicillin susceptible S. aurueus bacteremia, cefazolin is non-inferior to flucloxacillin or cloxacillin with respect to 90 day mortality associated with lower incidence of acute kidney injury.