Comparative Pharmacology
Head-to-head clinical analysis: NORETHINDRONE AND ETHINYL ESTRADIOL AND FERROUS FUMARATE versus PROVERA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NORETHINDRONE AND ETHINYL ESTRADIOL AND FERROUS FUMARATE versus PROVERA.
NORETHINDRONE AND ETHINYL ESTRADIOL AND FERROUS FUMARATE vs PROVERA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Norethindrone is a progestin that suppresses gonadotropin release, inhibiting ovulation. Ethinyl estradiol is an estrogen that provides negative feedback on the hypothalamic-pituitary axis, further suppressing ovulation and altering cervical mucus and endometrial lining. Ferrous fumarate is an iron supplement for replacement of menstrual iron loss.
Provera (medroxyprogesterone acetate) is a progestin that binds to progesterone receptors, suppressing gonadotropin secretion, inhibiting endometrial growth, and inducing secretory changes in the endometrium. It also has antigonadotropic effects by reducing LH and FSH release from the pituitary.
One tablet (norethindrone 1 mg, ethinyl estradiol 10 mcg, and ferrous fumarate 75 mg) orally once daily at the same time each day for 28 consecutive days, starting on day 1 of menstrual cycle.
Oral: 5-10 mg daily for 5-10 days for secondary amenorrhea; 5-10 mg daily for 12-14 days per cycle in combination with estrogen for endometrial hyperplasia; 400-1000 mg/day IM monthly for endometriosis.
None Documented
None Documented
Norethindrone: 5-8 hours (terminal). Ethinyl estradiol: 13-27 hours (terminal). Clinical context: dosing interval is 24 hours based on ethinyl estradiol half-life.
Terminal elimination half-life is approximately 12-17 hours for medroxyprogesterone acetate (oral). With depot intramuscular injection, the half-life is extended to approximately 50 days due to slow absorption from the injection site.
Norethindrone: ~80% renal (as glucuronide and sulfate conjugates), ~20% fecal. Ethinyl estradiol: ~40% renal, ~60% fecal via enterohepatic recirculation. Ferrous fumarate: iron is absorbed and incorporated; excess excreted in feces as unabsorbed.
Renal (50-60% as metabolites), biliary/fecal (30-40%). Less than 1% excreted unchanged.
Category D/X
Category C
Progestin
Progestin