Comparative Pharmacology
Head-to-head clinical analysis: ORTHO NOVUM 1 50 21 versus ORTHO TRI CYCLEN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ORTHO NOVUM 1 50 21 versus ORTHO TRI CYCLEN.
ORTHO-NOVUM 1/50 21 vs ORTHO TRI-CYCLEN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive consisting of mestranol (estrogen) and norethindrone (progestin). Mestranol is converted to ethinyl estradiol, which suppresses gonadotropin release (FSH, LH) from the pituitary, inhibiting ovulation. Norethindrone induces changes in cervical mucus (increasing viscosity) and endometrial lining, creating a hostile environment for sperm implantation.
Combined estrogen-progestin oral contraceptive; suppresses gonadotropin release, inhibiting ovulation; increases cervical mucus viscosity and alters endometrial lining.
One tablet orally once daily for 21 days, followed by 7 tablet-free days. Each tablet contains 1 mg norethindrone and 50 mcg mestranol.
One tablet (norgestimate 0.180-0.215-0.250 mg/ethinyl estradiol 0.035 mg) orally once daily for 21 days, followed by 7 days of placebo or no tablets.
None Documented
None Documented
Norethindrone: biphasic terminal half-life 7-9 hours for parent compound, 8-11 hours for metabolites; clinical steady-state achieved after 5-7 days.
Norethindrone: ~8 hours (terminal). Ethinyl estradiol: ~12-15 hours (terminal). Clinical context: Steady-state achieved within 5-7 days; contraceptive efficacy maintained with daily dosing.
Renal 50-60% as glucuronide and sulfate conjugates of norethindrone and mestranol/metabolites; fecal 20-30% via biliary elimination.
Norethindrone: 60-80% renal (as metabolites), 20-40% fecal. Ethinyl estradiol: ~40% renal, ~60% fecal. Biliary excretion contributes to fecal elimination.
Category C
Category C
Hormonal Contraceptive
Hormonal Contraceptive