Surgical antibiotic prophylaxis for patients with a penicillin or cephalosporin allergy

Cefazolin is the mainstay of surgical antibiotic prophylaxis. It is a beta-lactam antibiotic that shares no common side-chains with other beta lactams (see Cross-reactivity between beta lactams), and is often tolerated in patients with a penicillin or cephalosporin allergy.

For patients with immediate nonsevere or delayed nonsevere hypersensitivity to penicillins, cefazolin can be used. Other cephalosporins may also be appropriate—seek expert advice.

For patients with immediate severe or delayed severe hypersensitivity to penicillins, a non–beta-lactam antibiotic must be used instead of cefazolin—for alternatives, see the relevant procedure.