Major
Probable
説明
Azithromycin and quetiapine both prolong the QT interval via hERG blockade; concurrent use significantly increases the risk of life-threatening arrhythmias.
機序
Additive hERG (IKr) potassium channel blockade prolongs ventricular repolarization; azithromycin also inhibits CYP3A4 modestly, potentially increasing quetiapine exposure.
臨床的意義
Multiple case reports and pharmacovigilance data document torsades de pointes with this combination.
対処法
Avoid combination; use alternative antibiotics (e.g., amoxicillin) when possible; if unavoidable, obtain ECG and correct electrolytes.