Hormone Replacement Therapy: Precautions

Certain groups of women should not use HRT. They include women with:

• breast cancer
• cancer of the uterus
• abnormal vaginal bleeding that has not been diagnosed
• high blood pressure that rises when HRT is used
• liver disease
• gallstones or diseases of the gallbladder

HRT can interact with other prescription medications that a woman may be taking. Women who are taking corticosteroids, drugs to slow the clotting of blood (anticoagulants), and rifampin should ask their doctor about possible interactions.

Combining estrogens with certain other medicines can cause liver damage. Among the drugs that may cause liver damage when taken with estrogens are:

• acetaminophen (Tylenol), when used in high doses over long periods
• anabolic steroids such as nandrolone (Anabolin) or oxymetholone (Anadrol)
• medicine for infections
• antiseizure medicines such as divalproex (Depakote), valproic acid (Depakene), or phenytoin (Dilantin)
• antianxiety drugs, including chlorpromazine (Thorazine), prochlorperazine (Compazine), and thioridazine (Mellaril).

In addition, estrogens may interfere with the effects of bromocriptine (Parlodel), used to treat Parkinson's

disease and other conditions; they may also increase the chance of toxic side effects when taken with cyclosporine (Sandimmune), a drug that helps prevent organ transplant rejection.

— Laith Farid Gulli, M.D.