An 8-year-old weighing 20 kg has culture-proven group A streptococcal pharyngitis. His family has poor medication compliance, and two siblings have had rheumatic fever. Which antibiotic strategy provides the most reliable protection against an initial attack of rheumatic fever?
- A Amoxicillin orally for 5 days
- B Single intramuscular injection of benzathine penicillin G, 600000 units ✓
- C Azithromycin orally for 3 days
- D Oral cephalexin for 7 days with repeat throat culture at completion
Correct answer: B. Single intramuscular injection of benzathine penicillin G, 600000 units
Explanation
A single intramuscular dose of benzathine penicillin G guarantees complete eradication of the organism regardless of compliance, which is decisive in this non-adherent family. The weight-appropriate dose below 27 kg is 600000 units. Oral regimens require a full 10 days of therapy, so the 5-day and 3-day courses listed are inadequate for rheumatic fever prevention. Azithromycin is reserved for penicillin allergy.
Reference: Nelson Textbook of Pediatrics, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.