Comparative Pharmacology
Head-to-head clinical analysis: ORTHO CYCLEN 28 versus ORTHO TRI CYCLEN LO.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ORTHO CYCLEN 28 versus ORTHO TRI CYCLEN LO.
ORTHO CYCLEN-28 vs ORTHO TRI-CYCLEN LO
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 estrogen (ethinyl estradiol) and progestin (norgestimate) oral contraceptive. Suppresses gonadotropin release, inhibiting ovulation; increases cervical mucus viscosity, impeding sperm penetration; alters endometrial lining, reducing implantation likelihood.
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 daily orally for 21 days, followed by 7 placebo tablets. Each active tablet contains 0.025 mg ethinyl estradiol and 0.18 mg norelgestromin (days 1-7), 0.215 mg norelgestromin (days 8-14), 0.25 mg norelgestromin (days 15-21).
None Documented
None Documented
Ethinyl estradiol: 13-27 hours; Norelgestromin (active metabolite of norgestimate): 28-52 hours. Terminal half-lives support once-daily dosing.
Norelgestromin: 15-20 hours; Ethinyl estradiol: 13-16 hours. Steady-state achieved within 7 days.
Renal (60-70% as metabolites, ~20% unchanged), Fecal (30-40% as metabolites); primarily conjugated metabolites of ethinyl estradiol and norgestimate.
Renal (∼40% as metabolites, <10% unchanged) and fecal (∼30% as metabolites); conjugated metabolites excreted in bile and undergo enterohepatic circulation.
Category C
Category C
Hormonal Contraceptive
Hormonal Contraceptive