Hormone Replacement Therapy Health Article

Definition

Hormone replacement therapy (HRT) is the use of synthetic or natural female hormones to make up for the decline or lack of natural hormones produced in a woman's body. HRT is sometimes referred to as estrogen replacement therapy (ERT), because the first medications that were used in the 1960s for female hormone replacement were estrogen compounds.

Estrogens

In order to understand how HRT works and the controversies surrounding it, women should know that there are different types of estrogen medications commonly prescribed in the United States and Europe. These drugs are given in a variety of prescription strengths and methods of administration. There are at present three estrogen compounds used in Western countries. Only the first two are readily available in the United States.

• Estrone. Estrone is the form of estrogen present in women after menopause. It is available as tablets under the brand name Ogen. The most commonly prescribed estrogen in the United States, Premarin, is a so-called conjugated estrogen that is a mixture of estrone and other estrogens.
• Estradiol. This is the form of estrogen naturally present in premenopausal women. It is available as tablets (Estrace), skin patches (Estraderm), or vaginal creams (Estrace).
• Estriol. Estriol is a weaker form of estrogen produced by the breakdown of other forms of estrogen in the body. This is the form of estrogen most commonly given in Europe, under the brand name Estriol. It is the only form that is thought not to cause cancer.

In addition to pills taken by mouth, skin patches, and vaginal creams, estrogen preparations can be given by injection or by pellets implanted under the skin. Estrogen implants, however, are used less and less frequently.

Progestins

Most HRT programs include progestin treatment with estrogen compounds. Progestins—sometimes called progestogens—are synthetic forms of progesterone that are given to reduce the possibility that estrogen by itself will cause cancer of the uterus. Progestins are commonly prescribed under the brand names Provera and Depo-Provera. Other common brand names are Norlutate, Norlutin, and Aygestin.

Estrogen/testosterone combinations

Women's ovaries secrete small amounts of a male sex hormone (testosterone) throughout their lives. Women who have had both ovaries removed by surgery are sometimes given testosterone along with estrogen as part of HRT. Combinations of these hormones are available as tablets under the brand name Estratest or as vaginal creams. Women who cannot take estrogens can use 1% testosterone cream by itself for problems with vaginal soreness.

Estrogen/tranquilizer combinations

There are several medications that combine estrogen with a tranquilizer like chlordiazepoxide (sold under the trade name Menrium) or meprobamate (sold under the trade name PMB). Many doctors warn against these combination drugs because the tranquilizers can be habit-forming.

Purpose

HRT has two primary purposes: preventive treatment against osteoporosis and heart disease; and relief of physical symptoms associated with menopause.

Menopausal symptoms

Women in midlife enter a stage of development called menopause, when their menstrual periods become irregular and finally stop. The early phase of this transition is called the perimenopause. In the United States, the average age at menopause is presently 50 or 51, but some women begin menopause as early as 40 and others as late as 55. It can take as long as 10 years for a woman to complete the process. Women who have had their ovaries removed surgically are said to have undergone surgical menopause.

Doctors have not always agreed on definitions of the menopause. Some use age as the baseline. Others define menopause as the point when a woman has had no menstrual periods for a full calendar year. Still others define menopause as the end of ovulation. It is not always clear, however, when a woman has had her last period or when she has stopped ovulating. In addition, women who take oral contraceptives can have breakthrough bleeding long after they have stopped ovulating. As a result, some doctors now measure the level of follicle-stimulating hormone (FSH) in a woman's blood to estimate whether the woman has entered menopause. During perimenopause, the FSH levels in a woman's blood rise as her body attempts to stimulate the release of ripe ova. An FSH level over 40 is considered an indicator of menopause.

During the menopausal transition, the levels of estrogen in the woman's body drop. The lowered estrogen level is responsible for a group of symptoms that include hot flashes (or flushes), weight gain, changes in skin texture, mood swings, heart palpitations, sleep disturbances, a need to urinate more frequently, and loss of sexual desire. The estrogen that is given in HRT can eliminate hot flashes, night sweats, lack of vaginal lubrication, and urinary tract problems. HRT will not prevent weight gain or wrinkles. It also does not cure depression in most women.