Toxicology USMLE Step 1 Practice Question
A 21-year-old woman presents to the ED confused and agitated 3 hours after taking MDMA at a nightclub. Vital signs show temperature 39.2°C, heart rate 128/min, blood pressure 148/92 mmHg, and respiratory rate 20/min. She subsequently experiences a generalized tonic-clonic seizure. Laboratory studies reveal severe hyponatremia (Na+ 118 mEq/L) and elevated urine osmolality. Urine drug screen is positive for amphetamines. Which mechanism best explains the electrolyte abnormality associated with this drug?
Answer choices
- ALoop diuretic use
- BInhibition of carbonic anhydrase
- CDistal renal tubular acidosis
- DAldosterone deficiency
- ESIADH with excess free water intakeCorrect answer
- FNephrogenic diabetes insipidus with excessive sweating
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