Penicillin-allergic prophylaxis options?

• A. Clindamycin 600 mg PO 30-60 minutes before; alternatives include azithromycin or clarithromycin.
• B. Amoxicillin 2 g PO 30-60 minutes before.
• C. Penicillin VK 500 mg qid.
• D. Cephalexin 2 g PO 30-60 minutes before.

Answer: (A)

When a patient is allergic to penicillin, the prophylactic antibiotic for dental procedures should avoid penicillin-type drugs and still provide reliable coverage of oral bacteria. Clindamycin given as a 600 mg oral dose 30 to 60 minutes before the procedure fits this need well, offering strong activity against the typical oral flora and good tissue penetration. If clindamycin can’t be used, macrolides such as azithromycin or clarithromycin are acceptable alternatives, also given about an hour before.

The other options rely on beta-lactam antibiotics. Amoxicillin, Penicillin VK, and cephalexin are penicillin-related drugs, so they’re not appropriate for someone with a penicillin allergy due to the risk of an allergic reaction. That’s why the first-choice non–penicillin option, with macrolide alternatives, is the best approach.