Which antibiotic is recommended for dental-procedure prophylaxis in patients with penicillin allergy?

• A. Amoxicillin 2 g
• B. Clindamycin 600 mg
• C. Azithromycin
• D. Cephalexin

Answer: (B)

Key concept: dental-procedure prophylaxis in patients with penicillin allergy relies on an antibiotic that covers the oral streptococci and anaerobes typical of dental flora, while avoiding beta-lactams.

Clindamycin at 600 mg taken orally about 30 to 60 minutes before the procedure is the best choice because it provides robust coverage of both viridans streptococci and oral anaerobes, which are the usual pathogens involved in dental infections. This makes it an effective alternative when penicillin cannot be used. Amoxicillin and cephalexin are beta-lactams and are avoided in penicillin-allergic individuals due to potential cross-reactivity, so they aren’t suitable here. Macrolides like azithromycin can be used in some penicillin-allergic patients, but they don’t provide as reliable anaerobic coverage for dental flora and have variable resistance, making clindamycin the preferred option for prophylaxis in this context.