Comparative Pharmacology
Head-to-head clinical analysis: ORTHO NOVUM 1 50 21 versus ORTHO NOVUM 1 80 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ORTHO NOVUM 1 50 21 versus ORTHO NOVUM 1 80 21.
ORTHO-NOVUM 1/50 21 vs ORTHO-NOVUM 1/80 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 contraceptive. Suppresses gonadotropin (FSH, LH) release from pituitary, inhibiting ovulation. Increases viscosity of cervical mucus, impeding sperm penetration. Induces endometrial thinning, reducing implantation likelihood.
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 orally once daily for 21 consecutive days, followed by 7 days off therapy.
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 terminal half-life: 8-11 hours; Mestranol (ethinyl estradiol pro-drug) terminal half-life: 10-15 hours (metabolite ethinyl estradiol). Clinical context: Steady-state reached in 5-7 days; once-daily dosing maintains therapeutic levels.
Renal 50-60% as glucuronide and sulfate conjugates of norethindrone and mestranol/metabolites; fecal 20-30% via biliary elimination.
Renal: ~60% (metabolites, primarily glucuronide and sulfate conjugates), Fecal: ~40% (biliary excretion of metabolites). Unchanged drug negligible.
Category C
Category C
Hormonal Contraceptive
Hormonal Contraceptive