estrogens conjugated, Premarin (cont.)

Pharmacy Author:
Medical and Pharmacy Editor:

There was an increased risk of impaired cognition and/or dementia among women over age 65 treated with either estrogens or estrogens and medroxyprogesterone.

PRESCRIPTION: Yes.

GENERIC AVAILABLE: No.

PREPARATIONS: Tablets: 0.3, 0.45, 0.625, 0.9, and 1.25 mg. Vaginal cream: 0.625 mg per gm of cream. Injection: 25 mg per vial

STORAGE: Conjugated estrogen tablets and cream should be stored at room temperature, between 15 C -30 C (59 F - 86 F). The injection should be stored between 2 C - 8 C (36 F - 46 F).

DOSING: To minimize side effects, the lowest effective oral dose of conjugated estrogens is used. The usual starting dose for treating symptoms associated with menopause and for preventing postmenopausal osteoporosis is 0.3 mg/day. The dose should be increased based on response.

Conjugated estrogens may be administered continuously or in a cyclical fashion (i.e., 25 days on treatment then 5 days off treatment).

Hypogonadism is treated cyclically with doses of 0.3 mg or 0.625 mg daily for 25 days followed by 5 days off treatment.

The dose for women who have had their ovaries removed or have ovarian failure is 1.25 mg daily for three weeks followed by one week off treatment. In reality, most women take estrogens continuously since during the week off treatment, symptoms return because of the lack of estrogen.

For treatment of breast cancer, the recommended dose is 10 mg daily for three months. Abnormal uterine bleeding due to hormonal imbalance is treated with one 25 mg intravenous or intramuscular injection. Another injection may be given in 6-12 hours if needed.

The vaginal cream is used for treating vulvar and vaginal atrophy, and the recommended dose is ½ to 2 g daily.

DRUG INTERACTIONS: Estrogens increase the liver's ability to manufacture factors that promote the clotting of blood. Because of this, patients receiving warfarin (Coumadin), a drug that thins the blood and prevents clotting by reducing clotting factors, need to be monitored for loss of the blood thinning effect if treatment with an estrogen is begun.

Rifampin (Rifadin), barbiturates, carbamazepine (Tegretol), griseofulvin (Grifulvin), phenytoin (Dilantin), St. John's wort, and primidone all increase the elimination of estrogen by enhancing the liver's ability to eliminate estrogens. Use of any of these medications with estrogens may result in a reduction of the beneficial effects of estrogens.

Medically Reviewed by a Doctor on 1/29/2015


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