Comparative Pharmacology
Head-to-head clinical analysis: HAILEY 1 5 30 versus LYBREL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: HAILEY 1 5 30 versus LYBREL.
HAILEY 1.5/30 vs LYBREL
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive containing ethinyl estradiol and desogestrel. Ethinyl estradiol suppresses gonadotropin release via negative feedback on the hypothalamic-pituitary axis; desogestrel, a progestin, inhibits ovulation and alters cervical mucus and endometrial receptivity.
Combination of levonorgestrel and ethinyl estradiol: suppression of gonadotropins (FSH and LH) via negative feedback, inhibiting ovulation; thickening of cervical mucus to impede sperm penetration; alteration of endometrium to reduce implantation likelihood.
One tablet (ethinyl estradiol 0.03 mg, levonorgestrel 0.15 mg) orally once daily at the same time each day for 21 days, followed by 7 placebo tablets. For continuous cycling, may take active tablets daily without placebo.
One tablet (levonorgestrel 0.1 mg/ethinyl estradiol 0.02 mg) orally once daily for 21 days, followed by 7 placebo tablets for 28-day cycle.
None Documented
None Documented
Terminal elimination half-life of ethinyl estradiol is 13-27 hours (mean 17 hours); for norgestimate, active metabolite norelgestromin has half-life 12-30 hours (mean 19 hours). Steady state reached after 7-14 days.
Terminal elimination half-life: 27 ± 8 hours; requires ~5 days to reach steady-state; clinical significance: missed doses lead to rapid loss of contraceptive efficacy.
Approximately 40% renal (as metabolites), 32% fecal (as metabolites), and <1% unchanged in urine.
Renal: 50-60% as metabolites, ~20% as parent drug; fecal: 30-40%; biliary: 10-20%.
Category C
Category C
Oral Contraceptive
Oral Contraceptive