esterified estrogens, Estratab (discontinued); Menest (cont.)

Pharmacy Author:
Medical and Pharmacy Editor:

SIDE EFFECTS: The most common endocrine side effects 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).

Other important side effects include:

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.

Medically Reviewed by a Doctor on 12/18/2014

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