roximately 1- to 2-fold with once-daily dosing. Steady-state is achieved by 3 days. The mean t1/2 is approximately 12 hours (95% CI: 12 to 13).
Special Populations
Gender, age, body mass index (BMI), and race were included as factors assessed in the population pharmacokinetic model to eva luate suvorexant pharmacokinetics in healthy subjects and to predict exposures in the patient population. Age and race are not predicted to have any clinically meaningful changes on suvorexant pharmacokinetics; therefore, no dose adjustment is warranted based upon these factors.
Suvorexant exposure is higher in females than in males. In females, the AUC and Cmax are increased by 17% and 9%, respectively, following administration of BELSOMRA 40 mg. The average concentration of suvorexant 9 hours after dosing is 5% higher for females across the dose range studied (10-40 mg). Dose adjustment of BELSOMRA is generally not needed based on gender only.
Apparent oral clearance of suvorexant is inversely related to body mass index. In obese patients, the AUC and Cmax are increased by 31% and 17%, respectively. The average concentration of suvorexant approximately 9 hours after a 20 mg dose is 15% higher in obese patients (BMI > 30 kg/m2) relative to those with a normal BMI (BMI ≤ 25 kg/m2).
In obese females, the AUC and Cmax are increased by 46% and 25%, respectively, compared to non-obese females. The higher exposure to suvorexant in obese females should be considered before increasing dose [see Dosage and Administration (2.2)].
The effects of renal and hepatic impairment on the pharmacokinetics of suvorexant were eva luated in specific pharmacokinetic studies.
Suvorexant exposure after a single dose was similar in patients with moderate hepatic insufficiency (Child-Pugh category 7 to 9) and healthy matched control subjects; however, the suvorexant apparent terminal half-life was increased from approximately 15 hours (range 10 - 22 hours) in healthy subjects to approximately 19 hours (range 11 - 49 hours) in patients with moderate hepatic insufficiency [see Use in Specific Populations (8.7)].
Suvorexant exposure (expressed as total and unbound concentrations) was similar between patients with severe renal impairment (urinary creatinine clearance ≤30 mL/min/1.73m2) and healthy matched control subjects. No dose adjustment is required in patients with renal impairment [see Use in Specific Populations (8.8)].
Drug Interactions
CNS-Active Drugs
An additive effect on psychomotor performance was observed when a single dose of 40 mg of suvorexant was co-administered with a single dose of 0.7 g/kg alcohol. Suvorexant did not affect alcohol concentrations and alcohol did not affect suvorexant concentrations [see Warnings and Precautions (5.1, 5.3) and Drug Interactions (7.1)].
An interaction study with a single dose of 40 mg suvorexant and paroxetine 20 mg at steady-state levels in healthy subjects did not demonstrate a clinically significant pharmacokinetic or pharmacodynamic interaction.
Effects of Other Drugs on BELSOMRA
The effects of other drugs on the pharmacokinetics of suvorexant are presented in Figure 1 as change relative to suvorexant administered alone (test/reference). Strong (e.g., ketoconazole or itraconazole) and moderate (e.g., diltiazem) CYP3A inhibitors significantly increased suvorexant exposure. Strong CYP3A inducers (e.g., rifampin) substantially decreased suvorexant exposure [see Drug Interactions (7.2)].
Figure 1:
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