Cardiovascular Drugs USMLE Step 1 Practice Question
A 41-year-old man with bipolar disorder on lithium monotherapy for 8 years presents with polyuria and polydipsia. Vital signs: BP 128/82 mmHg, HR 88/min, RR 16/min, temperature 37°C. Serum sodium 148 mEq/L; serum creatinine 0.9 mg/dL. Urine osmolality remains inappropriately low (180 mOsm/kg) after water deprivation and desmopressin administration, distinguishing this from central diabetes insipidus. Which medication most appropriately reduces his symptoms?
Answer choices
- AFurosemide
- BAmilorideCorrect answer
- CPhenylephrine
- DAcetazolamide
- EMannitol
- FDesmopressin
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