Kefzol (Cefazolin)

Cefazolin is a first‑generation cephalosporin used to treat infections caused by susceptible bacteria.

• Surgical prophylaxis: prevents postoperative bacterial infections in patients undergoing surgery.
• Urinary tract infections: eradicates causative organisms and resolves infection symptoms.
• Skin and soft tissue infections: treats cellulitis, abscesses and wound infections.
• Respiratory tract infections: effective against community‑acquired pneumonia and bronchitis.
• Bone and joint infections: used for osteomyelitis and septic arthritis caused by susceptible strains.

• Cefazolin exerts its antibacterial effect by binding to penicillin‑binding proteins (PBPs) on the bacterial cell wall. This binding blocks the transpeptidation step of peptidoglycan synthesis, weakening the wall and causing osmotic lysis, leading to rapid bacterial death, especially against Gram‑positive organisms and selected Gram‑negative bacteria.

Cefazolin may be associated with a range of adverse reactions, varying from mild to severe.

Common Side Effects

• Injection site reactions: pain, erythema, or swelling at the infusion site.
• Gastrointestinal upset: nausea, vomiting, or diarrhea.
• Transient elevation of liver enzymes: mild increase in ALT or AST.
• Hypersensitivity rash: mild skin rash or itching.

Serious or Rare Side Effects

• Anaphylaxis: severe, life‑threatening allergic reaction with hypotension and airway compromise.
• Clostridioides difficile colitis: severe diarrhea due to overgrowth of C. difficile.
• Hemolytic anemia: immune‑mediated destruction of red blood cells.

When using Cefazolin, clinicians should consider several safety measures.

• Renal impairment: dose adjustment may be required in patients with reduced kidney function.
• Allergy history: avoid in patients with known cephalosporin or penicillin hypersensitivity.
• Pregnancy and lactation: use only if clearly needed, as safety data are limited.
• Concurrent nephrotoxic drugs: monitor renal function when combined with aminoglycosides or NSAIDs.
• Superinfection: watch for secondary infections such as fungal or resistant bacterial overgrowth.
• Store at ambient temperature: keep below 25 °C, protect from light and moisture, and retain in original packaging.

Cefazolin can interact with other medicines, requiring attention to dosing and monitoring.

Major Interactions (Avoid)

• Aminoglycosides: increased risk of nephrotoxicity; avoid concurrent high‑dose therapy.
• Loop diuretics: may potentiate renal toxicity; monitor kidney function.
• Warfarin: cefazolin may enhance anticoagulant effect; check INR frequently.

Moderate Interactions (Monitor Closely)

• Probenecid: may reduce renal clearance of cefazolin; adjust dose if needed.
• Oral contraceptives: possible reduction in efficacy; advise alternative contraception.
• Live vaccines: may diminish vaccine response; schedule vaccinations appropriately.