Comparative Pharmacology
Head-to-head clinical analysis: NORLESTRIN 21 2 5 50 versus ORTHO NOVUM 7 14 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NORLESTRIN 21 2 5 50 versus ORTHO NOVUM 7 14 21.
NORLESTRIN 21 2.5/50 vs ORTHO-NOVUM 7/14-21
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.
Combination estrogen-progestin contraceptive: suppresses gonadotropin release, inhibits ovulation, thickens cervical mucus, alters endometrial receptivity.
One tablet orally once daily for 21 days, followed by 7 days off, then repeat.
One tablet containing 0.5 mg norethindrone/0.035 mg ethinyl estradiol (white tablets) on days 1-14, then one tablet containing 1 mg norethindrone/0.035 mg ethinyl estradiol (peach tablets) on days 15-21, then no tablets for 7 days; repeated cycles.
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.
Norethindrone: 10-12 hours (terminal), ethinyl estradiol: 13-27 hours (terminal); clinical context: steady state achieved within 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: ~40% as glucuronide and sulfate conjugates; Fecal: ~20%; Biliary: minor
Category C
Category C
Oral Contraceptive
Oral Contraceptive