Comparative Pharmacology
Head-to-head clinical analysis: PROMETRIUM versus PROVERA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PROMETRIUM versus PROVERA.
PROMETRIUM vs PROVERA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Progesterone binds to progesterone receptors in target tissues, promoting endometrial maturation, reducing uterine contractility, and suppressing ovulation.
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.
Oral: 200 mg once daily at bedtime for 12 consecutive days per 28-day cycle in combination with conjugated estrogens 0.625 mg daily. For secondary amenorrhea: 400 mg once daily at bedtime for 10 days. Intravaginal: 4% gel (90 mg) or 8% gel (180 mg) applied every other day for 6 doses in postmenopausal women with intact uterus on estrogen therapy.
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
Terminal half-life: Approximately 16-18 hours for oral micronized progesterone (Prometrium); permits twice-daily dosing for luteal phase support.
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.
Urine (50-60% as metabolites, <1% unchanged); feces (20-30% as metabolites); minor biliary elimination.
Renal (50-60% as metabolites), biliary/fecal (30-40%). Less than 1% excreted unchanged.
Category C
Category C
Progestin
Progestin