| Indication |
Used as a contraceptive and to treat secondary amenorrhea,
abnormal uterine bleeding, pain associated with endometriosis,
endometrial and renal cell carcinomas, paraphilia in males,
GnRH-dependent forms of precocious puberty, as well as to prevent
endometrial changes associated with estrogens. |
| Pharmacodynamics |
Medroxyprogesterone is a synthetic progestin more potent than progesterone. |
| Mechanism of action |
Progestins diffuse freely into target cells in the female
reproductive tract, mammary gland, hypothalamus, and the pituitary and
bind to the progesterone receptor. Once bound to the receptor,
progestins slow the frequency of release of gonadotropin releasing
hormone (GnRH) from the hypothalamus and blunt the pre-ovulatory LH
surge. |
| Absorption |
Rapidly absorbed from GI tract |
| Volume of distribution |
Not Available |
| Protein binding |
90% |
| Metabolism |
Hepatic |
| Route of elimination |
Following oral dosing, MPA is extensively metabolized in the liver
via hydroxylation, with subsequent conjugation and elimination in the
urine. Most MPA metabolites are excreted in the urine as glucuronide
conjugates with only minor amounts excreted as sulfates. |
| Half life |
50 days |
| Clearance |
- 64110 +/- 42662 mL/min [postmenopausal women under fasting conditions with a single Dose of 2 × 10 mg]
- 74123 +/- 35126 mL/min [postmenopausal women under fasting conditions with a single Dose of 8 × 2.5 mg]
- 41963 +/- 38402 mL/min [postmenopausal women following daily administration of one PROVERA 10 mg tablet for 7 days]
|
| Toxicity |
Side effects include loss of bone mineral density, BMD changes in
adult women, bleeding irregularities, cancer risks, and thromboembolic
disorders. |
