A 65-year-old man with severe COPD taking theophylline presents with nausea, tremor, and insomnia. Vital signs show HR 128 bpm, BP 142/88 mmHg, RR 22, temperature 37.2°C, and SpO2 94% on room air. He started ciprofloxacin three days ago for prostatitis. ECG reveals supraventricular tachycardia. Serum theophylline level is 24 mcg/mL (therapeutic range 10-20). He denies chest pain or dyspnea worsening. Which drug interaction most likely explains his toxicity?

  1. A)Roflumilast
  2. B)Montelukast
  3. C)Tiotropium
  4. D)TheophyllineGABARITO
  5. E)Ipratropium

Explicação

Theophylline is a nonspecific phosphodiesterase inhibitor and adenosine receptor antagonist with a narrow therapeutic index. It can cause nausea, tremor, insomnia, and tachyarrhythmias, and its levels rise with drugs that reduce its metabolism, making toxicity... Ver explicação completa e trilha adaptativa →

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