Drug Interaction Report

ADJUST DOSE: Coadministration with inhibitors of P-glycoprotein (P-gp) may increase the plasma concentrations of edoxaban, which is a substrate of the efflux transporter. In healthy volunteers, single-dose edoxaban systemic exposure (AUC) increased approximately 80% to 90% by erythromycin, dronedarone, and ketoconazole; 70% to 80% by cyclosporine and quinidine; 50% by verapamil; and 40% by amiodarone. The peak plasma concentration (Cmax) of edoxaban also increased by approximately 45% to 90% with these drugs.

MANAGEMENT: When used for the treatment of deep vein thrombosis and pulmonary embolism, the manufacturer recommends that edoxaban dosage be reduced to 30 mg once daily in patients receiving concomitant treatment with certain P-gp inhibitors including azithromycin, clarithromycin, erythromycin, oral itraconazole, oral ketoconazole, quinidine, and verapamil. This dosage recommendation is based on data from a clinical study, the Hokusai VTE study, and is limited to use with the specific P-gp inhibitors mentioned. Other P-gp inhibitors were not permitted in the study, and patients on antiretroviral therapy (ritonavir, nelfinavir, indinavir, saquinavir) as well as cyclosporine were excluded from the study. Following discontinuation of the P-gp inhibitor, edoxaban dosage should be returned to the regular dosage of 60 mg once daily. No dosage adjustment is recommended for edoxaban when used in the treatment of nonvalvular atrial fibrillation.

GENERALLY AVOID: Alcohol may potentiate some of the pharmacologic effects of suvorexant. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills. In addition, alcohol may increase the risk of cognitive and complex behavioral changes associated with the use of hypnotics including suvorexant, such as amnesia, anxiety, hallucinations, sleep-driving, and other neuropsychiatric symptoms.

ADJUST DOSE: Grapefruit juice may significantly increase the plasma concentrations of suvorexant. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit.

ADJUST DOSING INTERVAL: Administration with or soon after a meal may delay the gastrointestinal absorption of suvorexant. According to the product labeling, administration of suvorexant with a high-fat meal resulted in no meaningful change in peak plasma concentration (Cmax) or systemic exposure (AUC), but a delay in Tmax of approximately 1.5 hours.

MANAGEMENT: Concomitant use of suvorexant with alcohol should be avoided. Patients should be advised not to use suvorexant if they had alcohol that evening or before bed. Grapefruit juice should preferably be avoided; otherwise, the recommended dose of suvorexant is 5 mg when used with grapefruit juice and should not exceed 10 mg. Suvorexant may be taken with or without food; however, for faster sleep onset, suvorexant should not be administered with or soon after a meal.