Drug Interaction Report

ADJUST DOSE: Coadministration with weak inhibitors of CYP450 3A4 may increase the plasma concentrations of lemborexant, which is primarily metabolized by the isoenzyme. Concomitant use of a weak CYP450 3A4 inhibitor is predicted to increase lemborexant exposure by less than 2-fold. Increased exposure to lemborexant may increase the risk of adverse reactions such as central nervous system (CNS) depression, sleep paralysis, hallucinations, complex sleep behaviors, worsening of depression or suicidal ideation, nightmares, palpitations, or headache.

MANAGEMENT: The lemborexant dose should be limited to 5 mg no more than once per night when coadministered with weak CYP450 3A4 inhibitors.

GENERALLY AVOID: Grapefruit juice may increase the plasma concentrations of lemborexant, which is primarily metabolized by CYP450 3A4. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit. Inhibition of hepatic CYP450 3A4 may also contribute. The interaction has not been studied with grapefruit juice but has been reported for other CYP450 3A4 inhibitors. When coadministered with itraconazole, a potent CYP450 3A4 inhibitor, lemborexant peak plasma concentration (Cmax) and systemic exposure (AUC) increased approximately 1.4-fold and 3.8-fold, respectively. When coadministered with fluconazole, a moderate CYP450 3A4 inhibitor, lemborexant Cmax and AUC increased approximately 1.6-fold and 4.2-fold, respectively. In general, the effect of grapefruit juice is concentration-, dose- and preparation-dependent, and can vary widely among brands. Certain preparations of grapefruit juice (e.g., high dose, double strength) have sometimes demonstrated potent inhibition of CYP450 3A4, while other preparations (e.g., low dose, single strength) have typically demonstrated moderate inhibition. Increased exposure to lemborexant may increase the risk of adverse reactions such as central nervous system (CNS) depression, sleep paralysis, hallucinations, complex sleep behaviors, worsening of depression or suicidal ideation, nightmares, palpitations, or headache.

After administration of a high-fat, high-calorie meal (approximately 1000 calories with 500 to 600 calories from fat), lemborexant Cmax decreased by 23%, AUC increased by 18%, and the time to maximum concentration (Tmax) was delayed by 2 hours.

MANAGEMENT: The manufacturer makes no recommendation regarding administration with food; however, the time to sleep onset may be delayed if taken with or soon after a meal. Patients should avoid consumption of grapefruit, grapefruit juice, or supplements that contain grapefruit during treatment with lemborexant.

GENERALLY AVOID: Grapefruit and/or grapefruit juice may increase the systemic exposure to palbociclib. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit. Increased exposure to palbociclib may increase the risk of adverse effects such as infections, neutropenia, leukopenia, anemia, thrombocytopenia, anorexia, nausea, vomiting, diarrhea, stomatitis, alopecia, asthenia, peripheral neuropathy, and epistaxis.

ADJUST DOSING INTERVAL: Food may enhance the oral bioavailability of palbociclib capsules and reduce the intersubject variability of palbociclib exposure. According to the product labeling, absorption and exposure of palbociclib from its oral capsule formulation were very low in approximately 13% of the population when taken in the fasted state. Food intake increased the palbociclib exposure in this small subset of the population but did not alter exposure in the rest of the population to a clinically relevant extent. Compared to palbociclib capsules given under overnight fasted conditions, the population average palbociclib peak plasma concentration (Cmax) and systemic exposure (AUC) increased by 38% and 21%, respectively, when given with high-fat, high-calorie food (approximately 800 to 1000 calories; 150, 250, and 500 to 600 calories from protein, carbohydrate and fat, respectively); by 27% and 12%, respectively, when given with low-fat, low-calorie food (approximately 400 to 500 calories; 120, 250, and 28 to 35 calories from protein, carbohydrate and fat, respectively); and by 24% and 13%, respectively, when given with moderate-fat, standard calorie food (approximately 500 to 700 calories; 75 to 105, 250 to 350 and 175 to 245 calories from protein, carbohydrate and fat, respectively) one hour before and two hours after palbociclib capsule dosing.

MANAGEMENT: Patients should avoid consumption of grapefruit or grapefruit juice while on treatment with palbociclib. To avoid variability in drug absorption between doses, palbociclib capsules should be taken with food. Palbociclib tablet formulations may be taken with or without food.