Infectious Disease Compendium

Cefazolin (Ancef®, Kefzol®)


CrCl Formula

CrCl > 80: 500 mg - 2.0 g q 8 h iv.

CrCl 80-50: 500 mg - 2.0 g q 8 h iv.

CrCl 50-10: 500 mg - 1.0 g q 8 - 12 h iv.

CrCl < 10: 500 mg - 1.0 g q 18 - 24 h iv.

Hemodialysis: 250 mg - 500 mg after dialysis. I prefer 2 gram dose if it is 48 hours before the next dialysis and 3 grams if it is 72 hours before the next dialysis. Prevents underdosing.

Peritoneal dialysis: na

Obesity dosing

Important side effects

Important drug interactions

Cefazolin may produce hypoprothrombinemia and increase the anticoagulant effect of warfarin.

Rants and Screeds


When combined with probenecid, can use one a day and is an excellent method for treating outpatient cellulitis (better than ceftiaxone).

Treatment of choice

Use for

Streptococci of all types and methicillin susceptible S. aureus. Arthritis, Cellulitis, Cholangitis, Cholecystitis, Endocarditis - treatment and prophylaxis, Epididymitis, genital infections, Gonorrhea, Meningitis, Osteomyelitis, perinatal streptococcal disease prophylaxis, pneumococcal Pneumonia, Prostatitis, Bronchitis, COPD exacerbation, Pneumonia, Sepsis, surgical prophylaxis, Tetanus, UTI.

Don't use for


First generation cephalosporin.