Pituitary Disorders USMLE Step 1 Practice Question
A 45-year-old man presents 2 weeks after transsphenoidal pituitary surgery with polyuria (6 L/day) and polydipsia. Vital signs show HR 88/min, BP 128/82 mmHg, RR 16/min. Labs reveal serum osmolality 305 mOsm/kg, serum sodium 148 mEq/L, and urine osmolality 180 mOsm/kg. Urine specific gravity is 1.005. He denies recent diuretic use. Which medication is most appropriate?
Answer choices
- AHypertonic saline infusion
- BFree water loading
- CDesmopressin (DDAVP) replacementCorrect answer
- DFluid restriction to 1 L/day
- EThiazide diuretic
- FVasopressin receptor antagonist (vaptans)
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