ts of Co-administered Drugs on the Pharmacokinetics of Suvorexant
Effects of BELSOMRA on Other Drugs
In vitro metabolism studies demonstrate that suvorexant has the potential to inhibit CYP3A and intestinal P-gp; however, suvorexant is unlikely to cause clinically significant inhibition of human CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19 or CYP2D6. In addition, no clinically meaningful inhibition of OATP1B1, BCRP and OCT2 transporters is anticipated. Chronic administration of suvorexant is unlikely to induce the metabolism of drugs metabolized by major CYP isoforms. Specific in vivo effects on the pharmacokinetics of midazolam, warfarin, digoxin and oral contraceptives are presented in Figure 2 as a change relative to the interacting drug administered alone (test/reference) [see Drug Interactions (7.3)].
Figure 2:
Effects of Suvorexant* on the Pharmacokinetics of Co-administered Drugs
Monitor digoxin concentrations as clinically indicated [see Drug Interactions (7.3)].
Suvorexant 40 mg was eva luated in all studies, except midazolam where 80 mg suvorexant was administered.
13 NONCLINICAL TOXICOLOGY
13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility
Carcinogenesis
In a 26-week study in Tg.rasH2 mice, there was no evidence of suvorexant-induced neoplasms at oral doses of 25, 50, 200, and 650 mg/kg/day.
In a 2-year study in rats (oral suvorexant doses of 80, 160, and 325 mg/kg/day), increases in thyroid (follicular cell adenoma and combined adenoma/carcinoma in high-dose females; follicular cell adenoma in mid- and high-dose males) and liver (hepatocellular adenoma in high-dose males) neoplasms were observed. These findings were consistent with increased TSH and hepatic enzyme induction, respectively, which are mechanisms believed to be rodent-specific. Plasma exposures (AUC) at doses not associated with drug-induced neoplasms in rats were approximately 7 times that in humans at the maximum recommended human dose (MRHD) of 20 mg.
Mutagenesis
Suvorexant was negative in in vitro (bacterial reverse mutation and chromosomal aberration) and in vivo (mouse and rat micronucleus) assays.
Impairment of Fertility
In two separate studies, male and female rats were treated with suvorexant prior to and during mating and continuing in females to gestation day 7. Increases in peri-implantation loss and resorptions, resulting in a decrease in live fetuses, were observed at the highest doses tested (1200 or 325 mg/kg) when treated males and females were mated with untreated animals. At the no-effect dose for adverse effects on fertility in males and females, plasma AUCs were approximately 20 times that in humans at the MRHD.
13.2 Animal Toxicology and/or Pharmacology
In dogs, daily oral administration of suvorexant (5, 30 mg/kg) for 4-7 days resulted in behavior characteristic of cataplexy (e.g., transient limb buckling, prone posture) when presented with food enrichment, a stimulus demonstrated to induce cataplexy in dogs with hereditary narcolepsy.
In the 2-year carcinogenicity study in rats, an increased incidence of retinal atrophy was observed at all doses. Plasma AUCs at the lowest dose tested were approximately 7 times that in humans at the MRHD.
In subsequent studies of suvorexant in albino and pigmented rats, retinal atrophy was delayed in onset and, after approximately one year of dosing, was of lower incidence and severity in pigmented rats.
14 CLINICAL STUDIES
14.1 Controlled Clinical Studies
BELSO |
