Comparative Pharmacology
Head-to-head clinical analysis: LOESTRIN FE 1 20 versus LOESTRIN FE 1 5 30.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LOESTRIN FE 1 20 versus LOESTRIN FE 1 5 30.
LOESTRIN FE 1/20 vs LOESTRIN FE 1.5/30
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive consisting of ethinyl estradiol and norethindrone acetate. Inhibits gonadotropin secretion (FSH, LH) via negative feedback on the hypothalamic-pituitary-ovarian axis, suppressing ovulation. Increases cervical mucus viscosity and alters endometrial structure, impeding sperm penetration and implantation.
Suppresses gonadotropin (FSH and LH) release via estrogen and progestin feedback inhibition, preventing ovulation; increases cervical mucus viscosity and alters endometrial lining.
One tablet (norethindrone acetate 1 mg and ethinyl estradiol 20 mcg) orally once daily for 21 consecutive days, followed by one ferrous fumarate tablet (75 mg) orally once daily for 7 days.
One tablet orally once daily at the same time each day for 21 consecutive days, followed by 7 days of placebo (ferrous fumarate) tablets, then restart.
None Documented
None Documented
Norethindrone: 6-9 hours (terminal). Ethinyl estradiol: 13-27 hours (terminal, mean 16 hours). Steady-state reached within 5-7 days.
Norethindrone: ~5-14 hours (terminal); Ethinyl estradiol: ~13-27 hours (terminal). Clinically, steady-state achieved within 5-7 days.
Norethindrone: 50-60% renal (as metabolites), 20-30% fecal. Ethinyl estradiol: 40-50% renal (as glucuronide conjugates), 30-40% fecal (as sulfate conjugates).
Renal: ~50-60% (norethindrone metabolites); Fecal: ~20-30% (norethindrone); Ethinyl estradiol: primarily renal (~40-50%) and fecal (~20-50%) as glucuronide and sulfate conjugates.
Category C
Category C
Combined Oral Contraceptive
Combined Oral Contraceptive