In a cephalosporin-allergic patient undergoing surgery, which agents are appropriate alternatives for perioperative prophylaxis?

• A. Gentamicin and/or Vancomycin
• B. Cefotaxime
• C. Piperacillin-Tazobactam
• D. Aztreonam

Answer: (A)

When choosing perioperative prophylaxis for a patient who cannot receive cephalosporins, you want non–beta-lactam drugs that provide complementary coverage for the most likely pathogens. Vancomycin offers reliable Gram-positive coverage, including MRSA, which is important in many surgical settings. Gentamicin provides Gram-negative coverage, helpful for surgeries with risk of Enterobacterales or other gram-negative organisms. Using either one (or in some cases both) avoids beta-lactams while still delivering the needed prophylaxis. In contrast, a cephalosporin like cefotaxime would be inappropriate due to the allergy. Piperacillin-tazobactam is a beta-lactam and would be avoided in a cephalosporin-allergic patient because of cross-reactivity concerns. Aztreonam covers only Gram-negatives and misses Gram-positive organisms, making it insufficient as a sole prophylactic agent for most surgeries.