Start practicing

Pharmacology · single question

A patient has a prosthetic heart valve AND a penicillin allergy. Which antibiotic prophylaxis should be given before dental procedures?

  1. Amoxicillin 2g
  2. Azithromycin 500mg
  3. No prophylaxis needed (MVP only — prosthetic valves still require prophylaxis)
  4. Clindamycin 600mg orally 1 hour before procedure
Show answer and explanation

Correct answer: D. Clindamycin 600mg orally 1 hour before procedure

  • A. Amoxicillin 2g is for NON–penicillin-allergic patients.
  • B. Azithromycin 500mg is also acceptable per some guidelines (check your institution's protocol).
  • C. Mitral valve prolapse (without regurgitation and not in high-risk category) requires no prophylaxis — but a prosthetic valve IS high-risk.
  • D. Correct. PROSTHETIC HEART VALVES are in the HIGH-RISK category for infective endocarditis — antibiotic prophylaxis IS indicated before dental procedures. For penicillin-ALLERGIC patients: CLINDAMYCIN 600mg orally 1 hour before. (Note: 2021 AHA updates suggest clindamycin has been de-emphasized due to C. diff risk — some sources now prefer cephalosporins if not truly allergic to beta-lactams, or azithromycin/clarithromycin 500mg. Always verify current guidelines, but clindamycin remains the classic answer for this scenario.)

Practice Pharmacology questions Pharmacology study notes

More Pharmacology practice questions