In penicillin-allergic patients, which antibiotic serves as a commonly accepted alternative for IE prophylaxis?

• A. Azithromycin 500 mg.
• B. Amoxicillin 2 g.
• C. Clarithromycin 500 mg.
• D. Clindamycin 600 mg PO 30-60 minutes before.

Answer: (D)

In penicillin-allergic patients, the antibiotic chosen for infective endocarditis prophylaxis must avoid beta-lactams while reliably covering the oral streptococci that commonly cause endocarditis. Clindamycin fits this need well: given as a single dose of 600 mg before the procedure, it provides strong activity against oral flora and achieves good serum and tissue levels to help prevent bacteremia from dental work. Amoxicillin is a penicillin and therefore not appropriate for someone with a penicillin allergy. While macrolides like azithromycin or clarithromycin can be used as alternatives, clindamycin is the commonly accepted first-line non–beta-lactam option for prophylaxis in this setting.