A 19-year-old woman presents to her neurologist 6 weeks after starting valproic acid for newly diagnosed idiopathic generalized epilepsy. She reports tremor, progressive weight gain of 8 pounds over this period, and diffuse hair loss. She also notes that her menstrual period has not occurred in the past 2 months. Vital signs are stable with BP 118/76 mmHg, HR 88 bpm, RR 16/min, and temperature 37.2°C. Laboratory studies show: serum ammonia 95 μmol/L (normal <50), AST 28 U/L, ALT 31 U/L, total bilirubin 0.8 mg/dL, TSH 2.1 mIU/L. Which of the following best explains her clinical presentation?
- A)Hepatotoxicity with acute liver failure requiring immediate medication discontinuation
- B)Hypothyroidism secondary to valproic acid metabolism of thyroid hormone
- C)Hyperammonemia with secondary amenorrhea and endocrine dysfunctionGABARITO
- D)Teratogenic effects of valproic acid manifesting as congenital abnormalities
- E)Drug-induced systemic lupus erythematosus with multi-organ involvement
Explicação
Valproic acid is well-known for causing hyperammonemia through inhibition of the urea cycle and carbamoyl phosphate synthetase. The elevated ammonia (95 μmol/L, well above normal) directly causes neurological symptoms (tremor) and metabolic effects. Additional... Ver explicação completa e trilha adaptativa →