What is medroxyprogesterone, and how does it work (mechanism of action)?
Progestins and estrogens are the two major classes
of female hormones. Medroxyprogesterone is a derivative of the naturally
occurring female progestin, progesterone. 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. Once an
embryo implants in the endometrium and
pregnancy occurs,
progestins help maintain the pregnancy. At high doses, progestins can prevent
ovulation (release of the egg from the ovary) and thereby prevent pregnancy.
Progestins were first isolated in 1933, and progesterone itself was synthesized
in the 1940s.
What brand names are available for medroxyprogesterone?
Provera, Depo-Provera, Depo-Sub Q Provera 104
Is medroxyprogesterone available as a generic drug?
Yes
Do I need a prescription for medroxyprogesterone?
Yes
What are the side effects of medroxyprogesterone?
Breast tenderness and leakage of liquid from the nipple occur
rarely with medroxyprogesterone. 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 clots. Therefore, females requiring
progestin therapy are strongly encouraged to
quit smoking.
People with diabetes may experience difficulty controlling blood glucose when
taking medroxyprogesterone for unclear reasons. Therefore, increased monitoring
of blood sugar and adjustment of medications for
diabetes
is recommended.
The Women’s Health Initiative (WHI) study found an increased risk of
heart attacks,
breast cancer, blood clots, and
pulmonary emboli (blood clots that lodge in the lungs) in postmenopausal
women (50 to 79 years of age) who took medroxyprogesterone in combination with
estrogens for 5 years, as well as an increased risk of
dementia in the
women over age 65. Therefore, medroxyprogesterone should not be used for the prevention of
heart disease or dementia. 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.
QUESTION
If menopause occurs in a woman younger than ___ years, it is considered to be premature.
See Answer
What is the dosage for medroxyprogesterone?
The usual dose of medroxyprogesterone tablets is 5 or 10 mg daily.
- Secondary amenorrhea is treated for 5 to 10 days.
- Uterine bleeding is treated for
5 to 10 days beginning on day 16 or 21 of the menstrual cycle. - Endometrial
hyperplasia is treated for 12 to 14 consecutive days beginning on day 1 or 16 of
the menstrual cycle. - The dose for contraception is 150 mg every 3 months injected intramuscularly
or 104 mg injected subcutaneously every 3 months. - The dose for endometrial or
renal cancer is 400-1000 mg weekly initially followed by monthly maintenance
doses.
Which drugs or supplements interact with medroxyprogesterone?
:
Aminoglutethimide (Cytadren) may increase the elimination of
medroxyprogesterone by the liver leading to a decrease in the concentration of
medroxyprogesterone in blood and possibly a reduction in the effectiveness of
the medroxyprogesterone.
Is medroxyprogesterone safe to take if I’m pregnant or breastfeeding?
Medroxyprogesterone inhibits fertility at high doses. It should
not be given during pregnancy.
Medroxyprogesterone is secreted in
breast milk.
The effect on the infant has not been determined.
What else should I know about medroxyprogesterone?
What preparations of medroxyprogesterone are available?
- Tablets: 2.5, 5, and 10 mg.
- Intramuscular injection: 150 and
400 mg/ml. - Prefilled Syringe Suspension: 104 mg/0.65 ml
How should I keep medroxyprogesterone stored?
Medroxyprogesterone should be stored at room temperature, between 20
C and 25 C (68 F and 77 F).