Comparative Pharmacology
Head-to-head clinical analysis: NORINYL 1 80 21 DAY versus NORTREL 1 35 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NORINYL 1 80 21 DAY versus NORTREL 1 35 21.
NORINYL 1+80 21-DAY vs NORTREL 1/35-21
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive containing norethindrone (a progestin) and ethinyl estradiol (an estrogen). Inhibits ovulation by suppressing gonadotropin release (FSH and LH). Also increases cervical mucus viscosity and alters endometrial morphology.
Combination of ethinyl estradiol (estrogen) and norethindrone (progestin) suppresses gonadotropin (FSH and LH) release from the pituitary, inhibiting ovulation, altering cervical mucus to impede sperm penetration, and inducing endometrial changes that reduce implantation likelihood.
One tablet orally once daily for 21 days, followed by 7 days of no active treatment.
One tablet orally once daily for 21 days, followed by 7 days off, then repeat.
None Documented
None Documented
Norethindrone: 8-11 hours; Mestranol: 12-24 hours (metabolized to ethinyl estradiol with half-life 20-27 hours). Steady-state after 5-7 days.
Norethindrone: 5-14 hours; Ethinyl estradiol: 17-24 hours. Steady-state achieved after 10 days.
Renal (40-60% as metabolites), fecal (20-30%)
Renal 50-60% as metabolites, fecal 40-50% as conjugates, <1% unchanged
Category C
Category C
Oral Contraceptive
Oral Contraceptive