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Conjugated estrogens / medroxyprogesterone


The conjugated estrogen formulation is one of the most commonly prescribed medicines in the country, under the brand name Premarin.

The conjugated estrogen formulation is one of the most commonly prescribed medicines in the country, under the brand name Premarin. The hormones are purified from pregnant mares' urine.

Prempro provides a tablet that combines conjugated estrogens with medroxyprogesterone so a woman has to take only one single tablet daily.

Premphase also provides one dose of these estrogens daily. The pills taken on days 15 through 28 of the cycle contain medroxyprogesterone in addition to the conjugated estrogens.

Estrogen replacement therapy is prescribed primarily to relieve menopausal symptoms such as hot flashes.

It has also become a popular measure for preventing osteoporosis and reducing the risk of heart disease in postmenopausal women.

Side Effects and Interactions

Premphase has a number of potential side effects, including breakthrough menstrual bleeding, breast tenderness, bloating, nausea, vomiting, stomach pain, headache, gallbladder problems, liver tumors, depression, jaundice and high blood pressure.

Some women experience an increase in blood sugar and may go on to develop diabetes.

The skin may become more sensitive to the sun, so it is wise to use sunscreen and wear protective clothing (including a hat and sunglasses) if you will be out.

Some kinds of vaginal infections may be more common in women using estrogen. Candida or yeast overgrowth may be a problem.

Other adverse reactions include a change in weight, fluid retention, alteration in sex drive, hair loss, and change in the curvature of the cornea. This may make contact lenses inappropriate.

Report any suspected side effects to the physician promptly.

Your doctor should be notified immediately of any of the following symptoms: pain in the calf or groin, sudden shortness of breath or sharp chest pain, sudden severe headache, blurred vision or speech, weakness or numbness in an arm or leg, yellow skin or eyes or severe abdominal pain.

Let your doctor know if you suspect you may have become pregnant, if you feel seriously depressed, if you notice lumps in your breast, or if vaginal bleeding is abnormal.

Premphase may interact with several other medications, such as theophylline or beta blocker blood pressure pills.

The activity of the anticoagulant Coumadin and that of certain antidepressants may be altered.

Adequate intake of calcium and vitamins B6 and folic acid is important.

Other estrogens interact with alcohol and with grapefruit; it is not known if the conjugated estrogens in Premphase do.

Until the estrogenic activity of hops is further studied, taking this herb in combination with medicines such as oral contraceptives or hormone replacement therapy is an experiment best avoided.

In general, the herb chaste tea berry should not be combined with menopausal hormone replacement therapies.

Saw palmetto berries, which have both estrogenic and antiestrogenic activity, are not recommended for women using female hormones for hormone replacement therapy.

Check with your doctor and pharmacist before taking any other medicine or herbs while taking Premphase.

Special Precautions

There are a number of situations where Premphase may be inappropriate.

Pregnant women should not use this medication, as it could affect the fetus.

Women with a history of breast cancer or other malignant disease susceptible to estrogen are generally advised to avoid this hormone.

Blood clotting disorders such as thrombophlebitis are also a reason to be wary of Prempro.

Prolonged use of postmenopausal estrogen has been controversial because it increases the risk of endometrial carcinoma or cancer of the uterine lining.

Medroxyprogesterone, as supplied in Premphase, counteracts this danger to a large extent.

Vaginal bleeding could be an early warning sign of cancer, however, and requires immediate medical attention.

Medroxyprogesterone does not appear to be protective against the increased risk of breast cancer. Women with a strong family history of breast cancer will want to discuss this issue with their doctor.

Taking the Medicine

Premphase tablets are to be taken once a day.

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About the Author
Joe Graedon is a pharmacologist who has dedicated his career to making drug information understandable to consumers. His best-selling book, The People’s Pharmacy, was published in 1976 and led to a syndicated newspaper column, syndicated public radio show and web site. In 2006, Long Island University awarded him an honorary doctorate as “one of the country's leading drug experts for the consumer.”.
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