Drug Interaction Report

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as well as clinical and laboratory monitoring may be appropriate whenever a CYP450 3A4 inhibitor is added to or withdrawn from therapy.

GENERALLY AVOID: Grapefruit juice may significantly increase the plasma concentrations of orally administered everolimus. The mechanism is inhibition of CYP450 3A4 and P-glycoprotein activity in the gut wall by certain compounds present in grapefruit.

MANAGEMENT: Patients treated with everolimus should avoid consumption of grapefruit and grapefruit juice.

ADJUST DOSING INTERVAL: Food increases the systemic exposure of givinostat. An open-label, randomized, crossover, single dose food effect study conducted in 12 healthy males used givinostat liquid filled capsules. Subjects received a single oral dose of givinostat (100 mg) in the fasting state or after a high-fat standard meal, with a washout period of at least 1 week in between. The high-fat standard meal resulted in an increase in systemic exposure (AUC) and maximum plasma concentration (Cmax) of about 40% and 23%, respectively, when compared to the fasted state. Additionally, the time to maximum concentration (Tmax) was delayed slightly from 2 to 3 hours.

MANAGEMENT: Givinostat should be administered with food to increase its absorption. In the case of the oral suspension, this can also help mask its bitter taste.