Which option best describes common prophylaxis for infective endocarditis in patients without penicillin allergy?

• A. Amoxicillin
• B. Doxycycline
• C. Amoxicillin and macrolides for those allergic to penicillins
• D. Clindamycin

Answer: (C)

Infective endocarditis prophylaxis around dental procedures is about choosing an antibiotic that effectively covers the oral streptococci most likely to cause endocarditis. For patients who can take penicillins, amoxicillin is the standard first-line choice. If someone has a penicillin allergy, the approach switches to an alternative antibiotic, such as a macrolide (for example, azithromycin or clarithromycin).

The option that describes both parts—amoxicillin for those without penicillin allergy and a macrolide for those with penicillin allergy—best captures how prophylaxis is actually managed across patient scenarios, which is why it’s considered correct. Other choices are less accurate: doxycycline isn’t the standard first-line prophylaxis; clindamycin is a penicillin-allergy alternative but not the primary non-allergic option; and giving amoxicillin alone doesn’t address the necessary allergy-guided alternative.