Medroxyprogesterone acetate, administered parenterally in the recommended doses to women with adequate endogenous estrogen, transforms proliferative endometrium into secretory endometrium.
Medroxyprogesterone acetate inhibits (in the usual dose range) the secretion of pituitary gonadotropin which, in turn, prevents follicular maturation and ovulation.
Because of its prolonged action and the resulting difficulty in predicting the time of withdrawal bleeding following injection, medroxyprogesterone acetate is not recommended in secondary amenorrhea or dysfunctional uterine bleeding. In these conditions oral therapy is recommended.
LABORATORY TEST INTERACTIONS
The pathologist should be advised of progestin therapy when relevant specimens are submitted. The following laboratory tests may be affected by progestins including DEPO-PROVERA Sterile Aqueous Suspension:
- Plasma and urinary steroid levels are decreased (e.g. progesterone, estradiol, pregnanediol, testosterone, cortisol).
- Gonadotropin levels are decreased.
- Sex-hormone binding globulin concentrations are decreased.
- Protein bound iodine and butanol extractable protein bound iodine may increase. T3 uptake values may decrease.
- Coagulation test values for prothrombin (Factor II), and Factors VII, VIII, IX, and X may increase.
- Sulfobromophthalein and other liver function test values may be increased.
- The effects of medroxyprogesterone acetate on lipid metabolism are inconsistent. Both increases and decreases in total cholesterol, triglycerides, low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol have been observed in studies.