Comparative Pharmacology
Head-to-head clinical analysis: ORTHO NOVUM 1 50 21 versus ORTHO NOVUM 10 11 28.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ORTHO NOVUM 1 50 21 versus ORTHO NOVUM 10 11 28.
ORTHO-NOVUM 1/50 21 vs ORTHO-NOVUM 10/11-28
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 gonadotropins (FSH, LH) via negative feedback inhibition of hypothalamic-pituitary axis, preventing ovulation; increases cervical mucus viscosity, impeding sperm penetration; alters endometrial development, 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 daily for 28 days, starting on day 1 of menstrual cycle. Each tablet contains 1 mg norethindrone and 10 mcg ethinyl estradiol for first 10 tablets, then 1 mg norethindrone and 35 mcg ethinyl estradiol for next 11 tablets, followed by 7 placebo 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: 5-14 hours; Ethinyl estradiol: 8-20 hours. Steady state reached within 5 days. Clinical significance: missed doses may increase pregnancy risk due to rapid decline.
Renal 50-60% as glucuronide and sulfate conjugates of norethindrone and mestranol/metabolites; fecal 20-30% via biliary elimination.
Renal (50-60% as metabolites, <10% unchanged); fecal (30-40%) with biliary elimination of conjugates.
Category C
Category C
Hormonal Contraceptive
Hormonal Contraceptive