Major
Established
Description
Fluconazole substantially increases quetiapine plasma concentrations via CYP3A4 inhibition, raising the risk of quetiapine-mediated QT prolongation and torsades de pointes.
Mécanisme
Fluconazole is a potent CYP3A4 inhibitor that reduces quetiapine clearance; both drugs also independently block hERG channels, adding pharmacodynamic risk.
Signification clinique
Quetiapine AUC may increase several-fold; QTc prolongation and torsades de pointes cases have been reported with this combination.
Prise en charge
Avoid concurrent use; if antifungal therapy is required, use an azole with lower CYP3A4 inhibitory potential or reduce quetiapine dose with ECG monitoring.