Comparative Pharmacology
Head-to-head clinical analysis: N E E 1 35 28 versus NORTREL 1 35 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: N E E 1 35 28 versus NORTREL 1 35 21.
N.E.E. 1/35 28 vs NORTREL 1/35-21
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive; ethinyl estradiol and norethindrone suppress gonadotropin (FSH and LH) release, preventing ovulation. Also cause cervical mucus thickening and endometrial changes.
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 28 days; each tablet contains norethindrone 1 mg and ethinyl estradiol 35 mcg.
One tablet orally once daily for 21 days, followed by 7 days off, then repeat.
None Documented
None Documented
Ethinyl estradiol: ~15-19 hours (linear pharmacokinetics); Norethindrone: ~7-9 hours (terminal half-life; steady-state achieved within 5-7 days)
Norethindrone: 5-14 hours; Ethinyl estradiol: 17-24 hours. Steady-state achieved after 10 days.
Renal: ~50-60% (metabolites, primarily glucuronide conjugates); Fecal: ~30-40% (biliary excretion of metabolites); Unchanged drug: <5%
Renal 50-60% as metabolites, fecal 40-50% as conjugates, <1% unchanged
Category C
Category C
Oral Contraceptive
Oral Contraceptive