Comparative Pharmacology
Head-to-head clinical analysis: ORTHO NOVUM 1 50 21 versus ORTHO TRI CYCLEN 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ORTHO NOVUM 1 50 21 versus ORTHO TRI CYCLEN 21.
ORTHO-NOVUM 1/50 21 vs ORTHO TRI-CYCLEN 21
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.
Combination estrogen-progestin oral contraceptive; suppresses gonadotropin secretion (FSH, LH) via negative feedback, preventing ovulation; increases cervical mucus viscosity and alters endometrial receptivity.
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 daily for 21 days, followed by 7 days of placebo, then repeat. Each tablet contains 0.180 mg norgestimate and 0.035 mg ethinyl estradiol (days 1–7), 0.215 mg/0.035 mg (days 8–14), and 0.250 mg/0.035 mg (days 15–21). Oral route.
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.
Norgestimate: ~24 hours (terminal); ethinyl estradiol: ~17 hours (terminal). Steady-state achieved within 5-7 days; clinical significance: missed doses may increase contraceptive failure risk.
Renal 50-60% as glucuronide and sulfate conjugates of norethindrone and mestranol/metabolites; fecal 20-30% via biliary elimination.
Renal: ~70% (metabolites, primarily glucuronide and sulfate conjugates of norgestimate and ethinyl estradiol); Fecal: ~30% (biliary elimination of unchanged drug and metabolites).
Category C
Category C
Hormonal Contraceptive
Hormonal Contraceptive