Penicillin allergy
Cefazolin is often used for prophylaxis in penicillin-allergic patients, but such patients rarely may have allergic reactions to cephalosporins. When allergy prevents use of a cephalosporin, vancomycin or clindamycin can be used, but neither is effective against gram-negative bacteria, so some
Medical Letter consultants would add gentamicin (Garamycin, and others), ciprofloxacin (Cipro, and others), levofloxacin (Levaquin, 750 mg once) or aztreonam (Azactam), particularly for colorectal procedures, hysterectomies, and vascular surgery involving groin incisions.