Comparative Pharmacology
Head-to-head clinical analysis: N E E 1 35 28 versus TRI LEGEST 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: N E E 1 35 28 versus TRI LEGEST 21.
N.E.E. 1/35 28 vs TRI-LEGEST 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 estrogen-progestin contraceptive; suppresses gonadotropins (FSH, LH), inhibits ovulation, alters cervical mucus and endometrium.
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 tablet-free days. Each tablet contains norgestimate 0.18 mg/ethinyl estradiol 0.025 mg (days 1-7), norgestimate 0.215 mg/ethinyl estradiol 0.025 mg (days 8-14), norgestimate 0.25 mg/ethinyl estradiol 0.025 mg (days 15-21).
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)
Ethinyl estradiol: 13-27 hours (mean ~17 hours); norgestimate active metabolite (norelgestromin): 22-36 hours (mean ~28 hours). Steady-state achieved within 5-10 days.
Renal: ~50-60% (metabolites, primarily glucuronide conjugates); Fecal: ~30-40% (biliary excretion of metabolites); Unchanged drug: <5%
Renal: approximately 50-60% as metabolites; fecal: approximately 40-50% (ethinyl estradiol and norgestimate metabolites excreted in bile and feces); less than 1% unchanged in urine.
Category C
Category C
Oral Contraceptive
Oral Contraceptive