Comparative Pharmacology
Head-to-head clinical analysis: LOESTRIN 21 1 5 30 versus NORCEPT E 1 35 28.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LOESTRIN 21 1 5 30 versus NORCEPT E 1 35 28.
LOESTRIN 21 1.5/30 vs NORCEPT-E 1/35 28
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination estrogen-progestin contraceptive: suppresses gonadotropin release, inhibiting ovulation; increases viscosity of cervical mucus, impeding sperm penetration; alters endometrial morphology.
Combination estrogen (ethinyl estradiol) and progestin (norethindrone) contraceptive: suppresses gonadotropin release, inhibits ovulation, thickens cervical mucus, and alters endometrial lining.
One tablet (norethindrone acetate 1.5 mg/ethinyl estradiol 30 mcg) orally once daily for 21 consecutive days, followed by 7 days off therapy.
1 tablet orally once daily for 21 days, followed by 7 days of placebo tablets.
None Documented
None Documented
Ethinyl estradiol: ~12-14 h; Norethindrone: ~5-12 h. Steady-state achieved in ~5-10 days.
Norethindrone: 5-14 hours; ethinyl estradiol: 13-27 hours. The terminal half-life of norethindrone is about 10 hours, allowing once-daily dosing; ethinyl estradiol's longer half-life contributes to steady-state concentrations within 3-5 days.
Primarily hepatic metabolism; ~40-60% renal, 20-30% biliary/fecal.
Renal (primarily as metabolites) and fecal; approximately 50-60% excreted in urine, 30-40% in feces. Ethinyl estradiol and norethindrone are extensively metabolized via hydroxylation and conjugation; glucuronide and sulfate conjugates are eliminated in urine and bile.
Category C
Category C
Combined Oral Contraceptive
Combined Oral Contraceptive