Comparative Pharmacology
Head-to-head clinical analysis: ORTHO CYCLEN 28 versus ORTHO NOVUM 1 50 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ORTHO CYCLEN 28 versus ORTHO NOVUM 1 50 21.
ORTHO CYCLEN-28 vs ORTHO-NOVUM 1/50 21
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive containing ethinyl estradiol and norgestimate. The primary mechanism is inhibition of gonadotropin secretion (FSH and LH) via negative feedback on the hypothalamic-pituitary axis, thereby suppressing ovulation. Additional effects include thickening of cervical mucus (impedes sperm penetration) and alterations in the endometrium (reduces implantation likelihood).
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.
One tablet (0.18 mg norgestimate/0.035 mg ethinyl estradiol) orally once daily for 28 days, first tablet on day 1 of menstrual cycle with 7 placebo tablets in last 7 days.
One tablet orally once daily for 21 days, followed by 7 tablet-free days. Each tablet contains 1 mg norethindrone and 50 mcg mestranol.
None Documented
None Documented
Ethinyl estradiol: 13-27 hours; Norelgestromin (active metabolite of norgestimate): 28-52 hours. Terminal half-lives support once-daily dosing.
Norethindrone: biphasic terminal half-life 7-9 hours for parent compound, 8-11 hours for metabolites; clinical steady-state achieved after 5-7 days.
Renal (60-70% as metabolites, ~20% unchanged), Fecal (30-40% as metabolites); primarily conjugated metabolites of ethinyl estradiol and norgestimate.
Renal 50-60% as glucuronide and sulfate conjugates of norethindrone and mestranol/metabolites; fecal 20-30% via biliary elimination.
Category C
Category C
Hormonal Contraceptive
Hormonal Contraceptive