Comparative Pharmacology
Head-to-head clinical analysis: AMEN versus NORETHINDRONE ACETATE AND ETHINYL ESTRADIOL AND ETHINYL ESTRADIOL AND FERROUS FUMARATE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: AMEN versus NORETHINDRONE ACETATE AND ETHINYL ESTRADIOL AND ETHINYL ESTRADIOL AND FERROUS FUMARATE.
AMEN vs NORETHINDRONE ACETATE AND ETHINYL ESTRADIOL AND ETHINYL ESTRADIOL AND FERROUS FUMARATE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Progesterone receptor agonist; induces secretory endometrium, inhibits gonadotropin release, and alters cervical mucus.
Combination of norethindrone acetate (progestin) and ethinyl estradiol (estrogen) suppresses gonadotropin (FSH and LH) release from the pituitary, inhibiting ovulation, thickening cervical mucus to impede sperm penetration, and altering endometrial lining to reduce implantation. Ethinyl estradiol (in 7-day extended regimen) maintains hormone levels. Ferrous fumarate provides iron supplementation.
Medroxyprogesterone acetate (AMEN): 5-10 mg orally once daily for 5-10 days, starting on day 16 or 21 of menstrual cycle; also 150 mg IM every 3 months for contraception.
One tablet (containing norethindrone acetate 1 mg, ethinyl estradiol 20 mcg, and ferrous fumarate 75 mg) orally once daily for 28-day cycle (21 active pills, 7 placebo with ferrous fumarate).
None Documented
None Documented
Terminal elimination half-life is approximately 4-6 hours. In severe hepatic impairment, half-life may be prolonged up to 12 hours.
Norethindrone: Terminal half-life approximately 8–11 hours. Ethinyl estradiol: Terminal half-life approximately 13–27 hours (mean 17 hours). Clinical context: Steady state reached after 5–7 days.
Primarily hepatic metabolism to inactive metabolites, with <1% excreted unchanged in urine. Fecal elimination of metabolites accounts for ~30%.
Norethindrone acetate: Urine (39% as metabolites, 1% unchanged); Feces (35% as metabolites). Ethinyl estradiol: Urine (40% as glucuronide conjugates, <1% unchanged); Feces (40% as metabolites). Ferrous fumarate: Iron absorbed and utilized; unabsorbed iron excreted in feces.
Category C
Category D/X
Progestin
Progestin