Comparative Pharmacology
Head-to-head clinical analysis: ORTHO CYCLEN 21 versus ORTHO TRI CYCLEN LO.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ORTHO CYCLEN 21 versus ORTHO TRI CYCLEN LO.
ORTHO CYCLEN-21 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. Suppresses gonadotropin (FSH, LH) release via negative feedback, inhibiting ovulation. Increases cervical mucus viscosity and alters endometrial structure to impair sperm penetration and implantation.
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 (norgestimate 0.180 mg/ethinyl estradiol 0.035 mg for days 1-7, norgestimate 0.215 mg/ethinyl estradiol 0.035 mg for days 8-14, norgestimate 0.250 mg/ethinyl estradiol 0.035 mg for days 15-21) orally once daily for 21 days, followed by 7 placebo tablets (if included) or 7 drug-free days, then repeat.
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
Terminal elimination half-life: Norgestimate metabolite (norelgestromin) ~28 hours; Ethinyl estradiol ~17 hours (range 13-27 hours). Clinical context: Steady-state achieved within 10-14 days.
Norelgestromin: 15-20 hours; Ethinyl estradiol: 13-16 hours. Steady-state achieved within 7 days.
Approximately 40% renal (as metabolites), 60% biliary/fecal (as metabolites). Norgestimate metabolites are excreted primarily in urine (40-50%) and feces (50-60%). Ethinyl estradiol metabolites are excreted in urine (40%) and feces (60%).
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