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