Drug Interactions between everolimus and ivacaftor / lumacaftor

GENERALLY AVOID: Coadministration with potent inducers of CYP450 3A4 and/or P-glycoprotein (P-gp) may significantly decrease the blood concentrations and pharmacologic effects of everolimus. In a study of healthy volunteers, multiple doses of the potent inducer rifampin increased the oral clearance of everolimus by threefold, representing mean decreases in peak blood concentration (Cmax) and systemic exposure (AUC) of 58% and 63%, respectively.

MANAGEMENT: Concomitant use of everolimus with potent CYP450 3A4 and/or P-gp inducers should generally be avoided. Alternative therapeutic agents with less enzyme induction potential should be considered. Some manufacturers recommend that, if concomitant use is unavoidable, the daily everolimus dose should be doubled to achieve the recommended therapeutic range for the condition being treated. Please refer to the manufacturer's labeling for specific dosing information. If the potent CYP450 3A4 and/or P-gp inducer is discontinued, the everolimus dosage should be returned to the dosage used before the potent inducer was commenced after a washout period of approximately 3 to 5 days. Everolimus whole blood trough levels should be closely monitored during treatment, particularly 2 weeks after a dose increase, and 2 weeks after discontinuation of the potent inducers.

MONITOR: Coadministration with inhibitors of CYP450 3A4 and/or P-glycoprotein may increase the blood concentrations of everolimus following oral administration. Everolimus is a substrate of both the CYP450 3A4 isoenzyme and P-glycoprotein drug efflux transporter, thus their inhibition in the intestine can enhance the absorption of everolimus.

MANAGEMENT: The possibility of prolonged and/or increased pharmacologic effects of everolimus therapy should be considered during coadministration with CYP450 3A4 and/or P-glycoprotein inhibitors, including adverse effects such as pneumonitis, stomatitis, infection, dyspnea, diarrhea, anemia, leucopenia, thrombocytopenia, hyperglycemia, and hyperlipidemia. Dosage adjustments as well as clinical and laboratory monitoring may be appropriate whenever a CYP450 3A4 inhibitor is added to or withdrawn from therapy.