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Provera
Brand Names: Provera, Cycrin, Amen
Generic Name: Medroxyprogesterone acetate
Manufacturer: Pfizer
DRUG CLASS AND MECHANISM
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.
PREPARATIONS
Tablets: 2.5, 5, and 10 mg. Sterile aqueous suspension for intramuscular injection: 400mg/mL in 2.5 mL vials.
STORAGE
Medroxyprogesterone should be stored at room temperature, between 15-30°C (59-8677°F).
PRESCRIBED FOR
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.
DOSING
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.
DRUG INTERACTIONS
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.
PREGNANCY
Medroxyprogesterone inhibits fertility at high doses. Medroxyprogesterone should not be given during the first 4 months of pregnancy due to possible harm to the fetus.
NURSING MOTHERS
Medroxyprogesterone is secreted in breast milk. The effect on the infant has not been determined.
SIDE EFFECTS
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.
WARNING
Two-drug combination hormone replacement therapy (estrogen and progestin menopause HRT) can infrequently cause cancer of the breast, heart disease (e.g., heart attack), stroke, dementia, and blood clots in the lung (pulmonary embolism) or leg. Estrogens may also increase the risk of cancer of the ovary. These risks appear to depend on the length of time this combination is used and the amount of estrogen per dose. Therefore, two-drug HRT should be used for the shortest possible length of time at the lowest effective dose, so you obtain the benefits and minimize the chance of serious side effects from long-term treatment. Discuss the risks and benefits with your doctor. If you use this drug for an extended period, you should be evaluated at least once a year. See Notes section. Blood clots may be more likely to form during very long periods of sitting or if you are bedridden, as well as with certain types of surgery. If this applies to you, ask your doctor whether you should temporarily stop your medication.
USES
This medication is a female hormone. It is used to treat amenorrhea (lack of menstrual flow), abnormal bleeding from the uterus, or endometriosis. It is also used to treat certain types of cancer, and menopausal symptoms as part of combination hormone replacement therapy (estrogen and progestin HRT). Progestins such as medroxyprogesterone lower the risk of estrogen-related cancer of the uterus during HRT therapy. Combination HRT should not be used to prevent heart disease.
HOW TO USE
May be taken with food or immediately after a meal to prevent stomach upset. Take this medication as prescribed. It is usually taken for 5 to 13 days during the later end of the menstrual cycle. A menstrual period should begin within 3 to 10 days of stopping the medication. For treatment of cancer, the medication is usually taken more often. Follow the dosing schedule carefully. Consult your doctor or pharmacist if you have any questions.
SIDE EFFECTS
This medication may cause nausea, vomiting, headache, dizziness, sleeplessness, or irritability. These effects should disappear as your body adjusts to the medication. If they persist or become severe, inform your doctor promptly. Notify your doctor immediately if you experience any of the following infrequent side effects: dizziness or fainting, mental/mood changes (e.g., depression, memory loss), sudden severe headache, changes in vision, numbness or tingling in the arms or legs, swelling of the hands or feet, chest pain, shortness of breath, pain in the leg accompanied by swelling/warmth/ redness, changes in vaginal bleeding (spotting, breakthrough bleeding, prolonged or complete stoppage of bleeding). If you notice other effects not listed above, contact your doctor or pharmacist.
PRECAUTIONS
Before you take this medication, tell your doctor your medical history (and family history), including: high blood pressure, seizures, migraine headaches, diabetes, asthma, heart disease or blood vessel problems (e.g., stroke, heart attack), liver or kidney disease, blood clots, history of cancer, high blood level of cholesterol or fats, depression, excessive weight gain or fluid retention during menstrual cycle, jaundice (yellowing of skin or eyes). Because this drug can interfere with laboratory tests, tell the doctor and laboratory personnel that you take medroxyprogesterone. Due to the risk of fetal harm, this medication must not be used during pregnancy (especially during the first four months of pregnancy). If you become pregnant or think you may be pregnant, inform your doctor immediately. This drug passes into breast milk. Though there have been no reports (to date) of problems in nursing infants, breast-feeding while using very high doses of this medication is not recommended. Consult your doctor before breast-feeding.
DRUG INTERACTIONS
Tell your doctor what prescription and nonprescription drugs you are taking. Do not start or stop any medicine without doctor or pharmacist approval.
OVERDOSE
If overdose is suspected, contact your local poison control center or emergency room immediately. US residents can call the US national poison hotline at 1-800-222-1222. Canadian residents should call their local poison control center directly. Symptoms of overdose may include nausea, vomiting, sleepiness, and dizziness.
NOTES
Do not share this drug with others. Laboratory and/or medical tests (e.g., monthly breast self-exams, and yearly breast exams) should be performed to monitor for serious side effects.
MISSED DOSE
If you miss a dose, take as soon as remembered; do not take if it is almost time for the next dose, instead, skip the missed dose and resume your usual dosing schedule. Do not "double-up" the dose to catch up.
STORAGE
Store at room temperature between 59 and 86 degrees F (between 15 and 30 degrees C) away from moisture and sunlight. Do not store in the bathroom.
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