Comparative Pharmacology
Head-to-head clinical analysis: NORLESTRIN 21 2 5 50 versus ORTHO NOVUM 7 7 7 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NORLESTRIN 21 2 5 50 versus ORTHO NOVUM 7 7 7 21.
NORLESTRIN 21 2.5/50 vs ORTHO-NOVUM 7/7/7-21
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive containing an estrogen (ethinyl estradiol) and a progestin (norethindrone acetate). Inhibits ovulation by suppressing gonadotropin release. Increases viscosity of cervical mucus, impeding sperm penetration, and alters endometrial receptivity.
Combined hormonal contraceptive; primarily suppresses ovulation via inhibition of gonadotropin release (LH and FSH) from the pituitary. Also induces changes in cervical mucus and endometrium.
One tablet orally once daily for 21 days, followed by 7 days off, then repeat.
One tablet orally once daily for 21 days, followed by 7 days of no tablets. Each tablet contains norethindrone 0.5 mg/0.75 mg/1 mg and ethinyl estradiol 35 mcg, with biphasic or triphasic dosing per cycle.
None Documented
None Documented
Norethindrone: 8 hours (terminal); Ethinyl estradiol: 13 hours (terminal). Clinical context: Steady-state achieved after 3-5 days; dosing interval based on once-daily administration.
Ethinyl estradiol: 13-27 hours; norethindrone: 8-14 hours; with multiple dosing, steady state after 5-7 days.
Renal: 50-60% as metabolites (glucuronide and sulfate conjugates of norethindrone and ethinyl estradiol); fecal: 30-40% via biliary elimination; <1% unchanged.
Renal: <10% unchanged; biliary/fecal: ~50% as metabolites; extensive enterohepatic recirculation.
Category C
Category C
Oral Contraceptive
Oral Contraceptive