Interactions between posaconazole and Cardioquin (quinidine)
quinidine and posaconazole (Major Drug-Drug)
CONTRAINDICATED: Coadministration with posaconazole may significantly increase the plasma concentrations of quinidine. The proposed mechanism is posaconazole inhibition of quinidine metabolism via CYP450 3A4. The use of quinidine has been associated with prolongation of the QT interval, thus elevated plasma levels of the drug may potentiate the risk of ventricular arrhythmias such as ventricular tachycardia and torsade de pointes as well as cardiac arrest and sudden death. Posaconazole itself has also been associated with QT interval prolongation. Conversely, quinidine increases posaconazole clearance by induction of the UDP-glucuronosyltransferase glucuronidation and P-glycoprotein clearance pathways.
MANAGEMENT: Given the potential for serious and life-threatening adverse cardiac events associated with increased plasma levels of quinidine, the concomitant use with posaconazole is considered contraindicated.
