Treatment With Liraglutide—a Once‐Daily GLP‐1 Analog—Does Not Reduce the Bioavailability of Ethinyl Estradiol/Levonorgestrel Taken as an Oral Combination Contraceptive Drug

Liraglutide is a once-daily human GLP-1 analog for treatment of type 2 diabetes. Like other GLP-1 analogs liragluide delays gastric emptying which could potentially affect absorption of concomitantly administered oral drugs. This study investigated the effect of liraglutide on the pharmacokinetics of the components of an oral contraceptive (ethinyl estradiol/levonorgestrel). Postmenopausal healthy women (n = 21) were included. A single dose of this contraceptive was administered. Blood samples for ethinyl estradiol/levonorgestrel measurements were drawn until 74 hours post dosing of the contraceptive during liraglutide and placebo treatments. The 90% confidence interval (CI) of the ratio of the area under the curve (AUC) (1.06; 90% CI 0.99-1.13) for ethinyl estradiol (during liraglutide and placebo) was within defined limits demonstrating equivalence. The 90% CI for the ratio of AUC for levonorgestrel was not fully contained within the limits (1.18; 90% CI 1.04-1.34) (levonorgestrel AUC was 18% greater with liraglutide vs placebo). However equivalence was demonstrated for levonorgestrel AUC(0-t) (1.15; 90% CI 1.06-1.24). Equivalence was not demonstrated for maximum concentration (C(max)); values for ethinyl estradiol and levonorgestrel C(max) were 12% and 13% lower with liraglutide versus placebo respectively. Both reached C(max) approximately 1.5 hours later with liraglutide. No clinically relevant reduction in bioavailability of ethinyl estradiol/levonorgestrel occurred.