Antimicrobials USMLE Step 1 Practice Question
A 3-year-old child with acute otitis media presents with fever (39.2°C), HR 120/min, and otalgia. Cultures identify penicillin-resistant Streptococcus pneumoniae. He is prescribed amoxicillin-clavulanate. On day 14 of therapy, he develops jaundice and pruritus. Laboratory studies show ALT 340 U/L, AST 380 U/L, and elevated bilirubin. Abdominal ultrasound shows no gallstones. He denies diarrhea. Which antimicrobial component most likely caused this hepatotoxicity?
Answer choices
- AAccumulation of clavulanic acid in hepatocytes due to immature renal function
- BClavulanic acid-associated hepatotoxicity, manifesting as cholestatic injuryCorrect answer
- CBacterial superinfection of the liver by penicillin-resistant S. pneumoniae
- DAmoxicillin allergy with immune-mediated hepatitis
- EDrug-induced fatty liver disease from amoxicillin metabolism
- FAmoxicillin-induced acute hemolytic anemia leading to secondary hyperbilirubinemia and jaundice
See the full explanation
Get the correct-answer rationale, why each distractor is wrong, the underlying mechanism, and high-yield associations — plus adaptive practice that targets your weak areas — with a free MedBoardPRO account.