Comparative Pharmacology
Head-to-head clinical analysis: NORLESTRIN 28 1 50 versus TRIPHASIL 28.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NORLESTRIN 28 1 50 versus TRIPHASIL 28.
NORLESTRIN 28 1/50 vs TRIPHASIL-28
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination estrogen-progestin oral contraceptive; suppresses gonadotropin release via negative feedback on pituitary, inhibits ovulation, thickens cervical mucus, alters endometrial receptivity.
Combination estrogen-progestin contraceptive; suppresses gonadotropin secretion, inhibits ovulation, alters cervical mucus and endometrium.
One tablet orally once daily, each containing norethindrone 1 mg and ethinyl estradiol 50 mcg.
1 tablet orally once daily for 28 days; each tablet contains levonorgestrel 0.050 mg and ethinyl estradiol 0.030 mg (6 days), levonorgestrel 0.075 mg and ethinyl estradiol 0.040 mg (5 days), levonorgestrel 0.125 mg and ethinyl estradiol 0.030 mg (10 days), followed by 7 inert tablets. The first dose is taken on the first Sunday after onset of menstruation or on day 1 of the menstrual cycle.
None Documented
None Documented
Norethindrone: 8 hours; ethinyl estradiol: 12-15 hours; steady state achieved within 5-10 days.
Levonorgestrel: terminal half-life 11-45 hours (mean 24-30 h); Ethinyl estradiol: terminal half-life 10-27 hours (mean 17 h). Steady-state reached after 5-7 days.
Norethindrone: 40% renal, 60% fecal; ethinyl estradiol: 40% renal, 60% fecal.
Renal (about 50-60% as metabolites, <10% unchanged), fecal (about 30-40% via biliary elimination). Ethinyl estradiol undergoes enterohepatic recirculation.
Category C
Category C
Oral Contraceptive
Oral Contraceptive