Drug Interactions between clofazimine and gepirone

Consumer information for this interaction is not currently available.

ADJUST DOSE: Coadministration with moderate CYP450 3A4 inhibitors may increase the plasma concentrations of gepirone, which is primarily metabolized by the isoenzyme. When subjects who were at steady state on the moderate CYP450 3A4 inhibitor verapamil (80 mg three times daily) received a single dose of gepirone (18.2 mg), the maximum plasma concentration (Cmax) and systemic exposure (AUC) of gepirone increased by approximately 2.6-fold. The risk of adverse effects such as QT prolongation, serotonin syndrome, dizziness, nausea, insomnia, abdominal pain, and dyspepsia may be increased. The risk of QT prolongation in particular may be increased with concomitant use of moderate CYP450 3A4 inhibitors that are also able to prolong the QT interval (e.g., ciprofloxacin, crizotinib, erythromycin, fluconazole, ribociclib).

MANAGEMENT: When used in combination with a moderate CYP450 3A4 inhibitor, the manufacturer recommends a 50% reduction in the dose of gepirone. If the moderate CYP450 3A4 inhibitor also carries a risk of prolonging the QT interval, then obtaining more frequent electrocardiograms (ECGs) to monitor the QT interval is also advised. Patients should be counseled to seek immediate medical attention if they experience symptoms that could indicate the occurrence of torsade de pointes such as dizziness, lightheadedness, syncope, palpitations, irregular heartbeat, and/or shortness of breath.