GENERIC NAME: esterified estrogens
　

BRAND NAME: Estratan; Menest
DRUG CLASS AND MECHANISM: Esterified estrogens are a mixture of several estrogens, a type of female hormone. Estrogens cause growth and development of female sex organs and the maintenance of sex characteristics, including growth of underarm and pubic hair and shaping of body contours and skeleton. Estrogens also increase secretions from the cervix and growth of the inner lining of the uterus (endometrium). Estrogens reduce LDL - cholesterol ("bad" cholesterol) and increase HDL - cholesterol ("good" cholesterol) in the blood. Estrogens, when taken alone or in combination with a progestin (another type of female hormone), have been shown to reduce the risk of heart attack (myocardial infarction) and stroke by 40-50%. In addition, their bone-promoting effects reduce the risk for hip fracture from osteoporosis (a bone disease that occurs primarily in women after menopause when the body stops producing its own estrogens) by 25%.

PRESCRIPTION: yes

GENERIC AVAILABLE: yes

PREPARATIONS: Tablets: 0.3mg, 0.625mg, 1.25mg, 2.5mg.

STORAGE: Tablets should be stored between 2? (36癋) and 30癈 (86癋).

PRESCRIBED FOR: Esterified estrogens are prescribed for the treatment of the common symptoms associated with menopause (for, example, hot flashes and vaginal dryness), dysfunctional (excessive and painful) uterine bleeding, and prostate cancer, as well as for the prevention of bone fractures associated with osteoporosis, heart attacks, and strokes.

DOSING: Esterified estrogens are generally prescribed once daily.

DRUG INTERACTIONS:

Cyclosporine levels: Estrogens can inhibit the metabolism (destruction) of cyclosporine, resulting in increased cyclosporine blood levels. Such increased blood levels can result in kidney and/or liver damage. If the combination of estrogens and cyclosporine cannot be avoided, cyclosporine concentrations in the blood can be monitored, and the dose of cyclosporine can be adjusted to assure that its blood levels are not elevated.

Liver disease: Estrogens appear to increase the risk of liver disease in patients receiving dantrolene through an unknown mechanism. Women over 35 years of age and those with a history of liver disease are especially at risk.

Reduced effectiveness of anticoagulants: Estrogens increase the liver's ability to manufacture chemicals that are required in order for blood to clot. Therefore, patients receiving warfarin (Coumadin), which anticoagulates ("thins" the blood) by inhibiting the manufacture of the chemicals required for clotting, need to have the ability of their blood to clot monitored if an estrogen is added. If blood clots too easily, the dose of warfarin may need to be increased.

Reduced effectiveness: Rifampin, barbiturates, carbamazepine (Tegretol), griseofulvin, phenytoin (Dilantin) and primidone, can increase the elimination of estrogen by enhancing the liver's ability to metabolize (destroy) it. Use of these drugs may result in a reduction of the beneficial effects of estrogens.

PREGNANCY: Estrogens should not be used during pregnancy because of an increased risk of fetal abnormalities.

NURSING MOTHERS: Estrogens are secreted in milk and cause unpredictable effects in the infant. Therefore, they generally should not be used during breast-feeding.

SIDE EFFECTS: Among the most common endocrine side are breakthrough bleeding or spotting, loss of periods, or excessively prolonged periods, breast pain, breast enlargement, and changes in sexuality (increase or decrease in libido). Estrogens also may cause gallstones, hepatitis, migraine headaches, and fluid retention (swelling of the lower legs). Melasma (tan or brown patches) may develop on the forehead, cheeks, or temples. These may persist even after the estrogen is stopped. Estrogens may cause an increase in the curvature of the cornea, and, therefore, patients with contact lenses may develop intolerance to their lenses.

Blood clots: Blood clots are occasional but serious side effects of estrogen therapy and are dose-related, that is, they occur more frequently with higher doses. Cigarette smokers are at a higher risk than non-smokers. Therefore, patients requiring estrogen therapy are strongly encouraged to quit smoking.

Uterine cancer: Estrogens can promote a build-up of the lining of the uterus or endometrium (endometrial hyperplasia) and increase the risk of endometrial cancer. At diagnosis, endometrial cancers in estrogen users are generally of an earlier stage and a lesser degree of malignancy than in non-users. Survival, therefore, is better. The addition of a progestin to estrogen therapy prevents endometrial cancer from developing.

Breast cancer: Conflicting data exists on the association between estrogen therapy and breast cancer. There may be a small increase in risk. It is not clear if the addition of a progestin during estrogen therapy reduces the risk of breast cancer (as it does for uterine cancer).