A 71-year-old man with Alzheimer disease has taken donepezil 10 mg daily for 4 weeks. He presents with syncope, BP 98/62 mmHg, HR 48 bpm, RR 16, and SpO2 98% on room air. ECG shows a prolonged PR interval of 220 ms consistent with first-degree heart block. Physical exam reveals hyperactive bowel sounds. His wife reports increased social withdrawal and persistent nausea with two episodes of vomiting. Recent labs show normal electrolytes, normal troponin, and no QTc prolongation. He denies chest pain. Which of the following best explains these complications?
- A)Anticholinergic rebound from abrupt dose escalation
- B)Acetylcholinesterase inhibition causing excessive cholinergic activity at cardiac and GI sitesGABARITO
- C)Amyloid-beta deposition in the myocardium
- D)Donepezil accumulation from renal insufficiency
- E)QT prolongation from hepatotoxicity
Explicação
Donepezil inhibits acetylcholinesterase, increasing acetylcholine levels. Excess cholinergic activity at the vagus nerve and cardiac conduction system causes bradycardia, AV block (prolonged PR), and syncope. GI hypermotility causes nausea and diarrhea. CNS ef... Ver explicação completa e trilha adaptativa →