Interactions between vaprisol(conivaptan) and Bepridil (bepridil)
bepridil and conivaptan (Major Drug-Drug)
MONITOR CLOSELY: Coadministration with conivaptan may significantly increase the plasma concentrations of certain antiarrhythmic agents such as amiodarone, lidocaine, and quinidine. The mechanism is conivaptan inhibition of CYP450 3A4 metabolism. The interaction has not been specifically studied but could conceivably lead to serious and/or life-threatening reactions including cardiac arrhythmias and other toxicities. In pharmacokinetic studies with other drugs that are primarily metabolized by CYP450 3A4 such as midazolam, simvastatin, and amlodipine, conivaptan has increased systemic exposure (AUC) by 2- to 3-fold.
MANAGEMENT: Caution is advised if conivaptan must be used with antiarrhythmic agents that are primarily metabolized by CYP450 3A4 such as amiodarone, lidocaine, or quinidine. Pharmacologic response and plasma antiarrhythmic drug levels should be monitored more closely whenever conivaptan is added to or withdrawn from therapy, and the antiarrhythmic dosage adjusted as necessary.
