A 71-year-old man with chronic kidney disease (eGFR 25 mL/min/1.73m²) presents with severe bilateral Achilles tendon pain on day 3 of levofloxacin 500 mg daily for urinary tract infection. Vital signs show BP 88/52, HR 118, RR 20. He experienced syncope this morning. Serum creatinine is 4.2 mg/dL. ECG reveals prolonged QTc interval. He denies chest pain or palpitations. Which mechanism best explains his syncope?
- A)Fluoroquinolone-induced tendinopathy directly damages the cerebellum
- B)The patient experienced a vasovagal response to tendon pain
- C)Levofloxacin accumulation prolongs QT interval, predisposing to torsades de pointesGABARITO
- D)Levofloxacin directly depresses myocardial contractility
- E)Chronic kidney disease alone is sufficient to cause syncope in elderly patients
Explicação
Fluoroquinolones, particularly levofloxacin, can prolong the QT interval, especially with reduced renal clearance. In this patient with eGFR 25, levofloxacin accumulates to toxic levels, causing marked QT prolongation and risk of torsades de pointes, a potenti... Ver explicação completa e trilha adaptativa →