A 38-year-old woman with chronic migraine headaches takes topiramate 100 mg daily for prophylaxis. She presents with progressive cognitive slowing, memory impairment, and difficulty concentrating over 3 weeks. Vital signs are stable (BP 118/76, HR 76, RR 14, Temp 37°C). Serum bicarbonate is 19 mEq/L. She denies headache improvement. Notably, her symptoms improve on weekends when she skips doses and worsen after resuming medication. Which mechanism best explains this adverse effect?
- A)Inhibition of monoamine oxidase in the prefrontal cortex
- B)Carbonic anhydrase inhibition leading to metabolic acidosis and CNS effectsGABARITO
- C)Sodium channel blockade in the cerebral cortex
- D)Serotonin antagonism at 5-HT1B receptors
- E)GABA-A receptor agonism causing excessive inhibitory tone
Explicação
Topiramate inhibits carbonic anhydrase, causing metabolic acidosis and altered intracellular pH in neurons. This leads to cognitive impairment, memory problems, and concentration difficulties. The dose-dependent and reversible nature (improves on weekends) sup... Ver explicação completa e trilha adaptativa →