Medroxyprogesterone is a progestin that is derived from the naturally occurring female hormone progesterone. Progestins and estrogens comprise the two major classes of female hormones. Medroxyprogesterone is used to treat abnormal uterine bleeding promote menstrual cycles and to treat symptoms of the menopause.

Progestins are responsible for changes in the mucus and inner lining of the uterus endometrium during the second half secretory phase of the menstrual cycle. Progestins prepare the endometrium for implantation of the embryo and once an embryo implants in the endometrium i.e. pregnancy occurs progestins help maintain the pregnancy. At high doses progestins also prevent ovulation release of the egg from the ovary. Progestins were first isolated in 1933 and progesterone itself was synthesized in the 1940s.

The usual dose of medroxyprogesterone is 2.5 to 5 mg daily for 5 to 10 days for abnormal uterine bleeding and primary and secondary amenorrhea. When used to induce menstruation therapy can be started at any time. When treating abnormal uterine bleeding therapy should be started on the 16th or 21st day of the menstrual cycle. When used in combination with estrogens for example for treating postmenopausal symptoms the dose of medroxyprogesterone is 1.5 to 5 mg daily. Although medroxyprogesterone is approved for cyclic therapy during only a portion of each 21 day cycle it usually is prescribed daily.

Breast tenderness and leakage of liquid from the nipple occur rarely. Various skin reactions including hives acne hair growth and hair loss also have been reported occasionally. Break-through bleeding menstrual-like bleeding in the middle of the menstrual cycle vaginal spotting of blood changes in menstrual flow increased or decreased weight nausea fever insomnia and jaundice have all been reported.

Blood clots are an occasional serious side effect of progestin therapy and cigarette smokers are at a higher risk for them. Therefore patients requiring progestin therapy are strongly encouraged to quit smoking .

Diabetic patients may experience difficulty in controlling blood glucose when taking medroxyprogesterone so monitoring of blood sugar and adjustment of medications for diabetes is recommended. The reason for this is not well understood.

The Women’s Health Initiative study found an increased risk of heart attacks stroke breast cancer pulmonary emboli and blood clots in the veins in postmenopausal women 50-79 years old who took medroxyprogesterone in combination with estrogens for 5 years as well as an increased risk of dementia in the participants over age 65. Although medroxyprogesterone alone has not been demonstrated to promote breast cancer since breast cancer has progesterone receptors physicians usually avoid using progestins in women who have had breast cancer. Medroxyprogesterone should not be used for the prevention of heart disease.

Aminoglutethimide may increase the breakdown of medroxyprogesterone by the liver leading to a decrease in the concentration of medroxyprogesterone in blood and a possible reduction in effectiveness.

Medroxyprogesterone is used to promote menstruation when women do not begin naturally to menstruate at puberty called primary amenorrhea or if they stop menstruating before menopause called secondary amenorrhea. Medroxyprogesterone also is used for treating abnormal bleeding from the uterus in many situations though only after attempts to determine the cause of bleeding have been made. It is not used to treat bleeding due to fibroids tumors or other correctable causes of bleeding. Medroxyprogesterone is used in combination with estrogens for treating symptoms of menopause in order to prevent unchecked growth of the endometrium that may lead to endometrial cancer. It also is used for treating the pain of endometriosis.

Medroxyprogesterone should be stored at room temperature between 15-30°C 59-8677°F.