Question 1 of 15

A 55-year-old woman with bipolar disorder on chronic lithium presents with coarse tremor, unsteady gait, confusion, and nausea. Two weeks ago she was started on hydrochlorothiazide for hypertension and has been taking ibuprofen for a sprain. She also reports several liters of dilute urine daily and persistent thirst. Serum lithium is 2.3 mEq/L and creatinine is mildly elevated. Which statement best explains her presentation and management?

• A.Thiazides and NSAIDs reduce lithium clearance and raised her level; hemodialysis is indicated for severe toxicity with significant neurologic signs and renal impairment
• B.Her polyuria reflects lithium-induced SIADH, which will correct with fluid restriction
• C.A level of 2.3 mEq/L is within the therapeutic range, so the symptoms are unrelated to lithium
• D.Loop diuretics like furosemide raise lithium levels and should be substituted for the thiazide
• E.The nephrogenic diabetes insipidus is best treated by increasing the lithium dose to overcome renal resistance