Comparative Pharmacology
Head-to-head clinical analysis: HAILEY 1 5 30 versus KELNOR 1 50.
Peer-Reviewed Evidence
Head-to-head clinical analysis: HAILEY 1 5 30 versus KELNOR 1 50.
HAILEY 1.5/30 vs KELNOR 1/50
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 hormonal contraceptive: ethinyl estradiol provides estrogenic activity, suppressing gonadotropin release; norethindrone acetate provides progestational activity, inhibiting ovulation and causing cervical mucus thickening.
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 (norethindrone 1 mg/ethinyl estradiol 50 mcg) orally once daily, taken at the same time each day for 21 days, followed by 7 days of placebo.
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.
Ethinyl estradiol: biphasic, terminal half-life 13-27 hours (mean ~17 h); norethindrone: monoexponential, half-life 5-14 hours (mean ~8 h). Steady-state achieved after 3-5 days. Accumulation may occur in patients with hepatic impairment.
Approximately 40% renal (as metabolites), 32% fecal (as metabolites), and <1% unchanged in urine.
Renal: ~50% (as metabolites, primarily ethinyl estradiol glucuronide and sulfate conjugates; norethindrone metabolites). Fecal: ~35% (biliary excretion of conjugates followed by hydrolysis and elimination). Unchanged drug: <5%.
Category C
Category C
Oral Contraceptive
Oral Contraceptive