Endocrine Pharmacology USMLE Step 1 Practice Question
A 14-year-old boy presents with polyuria and polydipsia following a traumatic brain injury. Vital signs show HR 88/min, BP 118/76 mmHg, RR 16/min. Serum sodium is 148 mEq/L; urine osmolality is 210 mOsm/kg despite elevated serum osmolality. Water deprivation test is performed. Following administration of an ADH analog, urine osmolality increases substantially to 580 mOsm/kg. There is no history of recent nephrogenic medications. Which drug was administered?
Answer choices
- ATolvaptan
- BDemeclocycline
- COxytocin
- DDesmopressinCorrect answer
- EHydrocortisone
- FVasopressin
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