Beta Blockers USMLE Step 1 Practice Question
A 31-year-old woman with bipolar disorder started lithium 6 months ago. She now reports excessive thirst and polyuria. Vital signs show HR 78/min, BP 118/76 mmHg, RR 14/min. Labs reveal serum sodium 148 mEq/L and serum osmolality 305 mOsm/kg. Urine osmolality remains inappropriately low at 210 mOsm/kg despite desmopressin administration. She denies fever or recent infections. Which adverse effect of lithium best explains these findings?
Answer choices
- ASIADH
- BCentral diabetes insipidus
- CNephrogenic diabetes insipidusCorrect answer
- DFanconi syndrome
- EAcute tubular necrosis
- FMinimal change disease
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