Major
Probable
الوصف
Ciprofloxacin and quetiapine both prolong the QT interval and ciprofloxacin also increases quetiapine exposure via CYP3A4 inhibition.
الآلية
Ciprofloxacin inhibits CYP3A4, reducing quetiapine clearance, while both drugs independently block hERG channels, creating dual pharmacokinetic and pharmacodynamic QT prolongation.
الأهمية السريرية
Elevated quetiapine levels combined with additive QTc prolongation substantially raises the risk of life-threatening torsades de pointes.
التدبير
Avoid combination; select alternative antibiotics; if unavoidable, monitor ECG and consider temporary quetiapine dose reduction.