A patient with repaired tetralogy of Fallot (repair status not specified) and no drug allergy needs antibiotic prophylaxis before an invasive dental procedure. Which regimen is appropriate?

Correct answer: A. Amoxicillin 2 g orally, 1 hour before

• A. Correct. Repaired congenital heart disease with residual defects (or within 6 months of repair with prosthetic material) requires prophylaxis; amoxicillin 2 g one hour before is first-line.
• B. Oral penicillin V is not the AHA prophylaxis regimen for dental procedures.
• C. Clindamycin is the regimen for true penicillin allergy — this patient has no allergy. (Note: AHA now prefers azithromycin/cephalexin over clindamycin.)
• D. No antibiotic applies only to COMPLETELY repaired CHD without residual defects beyond 6 months — not stated here.

Note: If the lesion were fully repaired with no residual defect and >6 months out, no prophylaxis would be needed. Because repair status is unspecified, amoxicillin 2 g is the safe keyed answer.