Effects of Lemborexant on the Pharmacokinetics of Oral Contraceptives: Results From a Phase 1 Drug‐Drug Interaction Study in Healthy Females

Lemborexant is a dual orexin receptor antagonist approved in multiple countries including the United States, Canada, and Japan for the treatment of insomnia in adults. As women of childbearing potential may be prescribed insomnia drugs, a drug‐drug interaction study was conducted. This single‐center, open‐label, fixed‐sequence study examined potential drug‐drug interactions between lemborexant and an oral contraceptive (OC) in healthy females (18–44 years, n = 20). The purpose of this study was to determine the effect of lemborexant 10 mg (at steady state) on the pharmacokinetics of a single dose of OC (0.03 mg ethinyl estradiol and 1.5 mg norethindrone acetate), assess the effect of a single dose of OC on lemborexant pharmacokinetics, and evaluate safety and tolerability of lemborexant and OC coadministration. Ethinyl estradiol maximum plasma drug concentration was not altered by lemborexant coadministration; area under the curve from zero time to the last quantifiable concentration was slightly increased, by 13%. No clinically relevant effects on norethindrone acetate pharmacokinetics were observed. Coadministration of OC with lemborexant had no clinically relevant effect on the steady‐state pharmacokinetics of lemborexant. Adverse events were consistent with the known safety profile. These results support the conclusion that lemborexant and OC can be coadministered without dose adjustment.