Dosing
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.
For bacteremia/endocarditis, "achieving a cefazolin concentration target of 40 mg/L with a success rate of 90 % at least and with an a GFR of 30, 60, 90 and 120 mL/min requires a daily dose of 2.6, 4.3, 6.1 and 8.0 g/day, respectively (PubMed)."
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 under-dosing.
Peritoneal dialysis: na
Important side effects
Important drug interactions
Cefazolin may produce hypoprothrombinemia and increase the anticoagulant effect of warfarin.
Rants and Screeds
Pearls
When combined with probenecid, it can use once a day and is an excellent method for treating outpatient cellulitis (better than ceftriaxone).
Some S. aureus makes beta-lactamases that can kinda sorta degrade cefazolin (PubMed) and clinically there is no way to tell. And there is a cefazolin inoculum effect that decreases cefazolin efficacy (PubMed) in about half of patients. At least in Argentina. In Chicago, 4% of isolates had cefazolin inoculum effect (PubMed). The CIE can be overcome with the addition of a beta-lactamase inhibitor (PubMed). My take gets down, as always, to source control. The better the source control, the more you can use cefazolin. If source control problematic (CNS infections, endocarditis, undrainable pus) the more you should use nafcillin. One way to suspect CIE is it is seen in clindamycin and erythromycin-resistant strains (PubMed).
Treatment of choice
Maybe methicillin-susceptible S. aureus instead of an anti-staphylococcal penicillin.
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, UTI.
Don't use for
Class
First-generation cephalosporin.
Last Update: 08/03/19