What are the types of hormone therapy (HT)?
Doctors usually prescribe hormone therapy (HT) as a combination of estrogen and another female hormone, progesterone. Synthetic progesterone compounds are referred to as progestins. Long-term estrogen use without progesterone increases the risk of uterine cancer (endometrial cancer), whereas addition of progesterone counteracts this risk. Therefore, estrogen without progestin is usually only recommended for women who have had their uterus removed (hysterectomy). Estrogen is available as pills, tablets, patches, creams, mist sprays, or vaginal preparations (vaginal rings, vaginal tablets, or vaginal cream). The choice of estrogen preparation recommended by the doctor depends on the women's symptoms. For instance, vaginal creams, vaginal tablets, and vaginal rings are used for vaginal dryness, while pills or patches are used to ease hot flashes. Estrogen pills are also useful for vaginal dryness and are sometimes used along with vaginal creams, tablets, or rings.
Although progestin is usually taken in pill form, it is also available, together with estrogen, in patch form.
Doctors may prescribe different schedules for taking hormone therapy (HT). Every woman's hormone therapy (HT) treatment and schedule should be individualized based on her particular situation. Below are some standard forms of hormone therapy (HT) that are used:
Pills (oral therapy)
In order to avoid monthly vaginal bleeding, some women choose to take small doses of estrogen and progesterone together every day. This is called daily continuous therapy. Sometimes, daily continuous therapy can cause some irregular, unexpected vaginal bleeding for the first several months of treatment, especially in younger women entering menopause. For these women, and for some other women, planned cyclic bleeding is more acceptable. In these women, progesterone is usually added to estrogen for the first 12 calendar days of the month.
Patches and spray mists (transdermal therapy)
Hormone therapy (HT) skin patches are to be worn on a continuous basis. Newer patches need to be changed once or twice per week. Combination estrogen/progesterone patches are available for women who have not undergone hysterectomy to prevent cancer of the uterus. Patches are as effective as oral hormone therapy (HT) for controlling hot flashes. Spray mists for ET are available as a transdermal spray used once daily.
Vaginal tablets, rings, and Creams
Estrogen vaginal tablets and creams are generally prescribed nightly for 2 weeks, and then reduced to twice per week as a long-term "maintenance therapy." There is a low level of absorption of estrogen into the body with the use of vaginal preparations as directed. Circulating blood levels of estrogen are slightly increased from vaginal estrogen use, and the long-term safety of vaginal estrogen rings, creams and tablets has not been clearly established (for example risk of uterine cancer, heart disease, or breast cancer). For this reason, occurrence of vaginal bleeding during any type of vaginal estrogen use should be promptly evaluated.
Vaginal estrogen rings are approved to treat genital dryness and irritation that can occur due to the lack of estrogen in women after menopause. A higher dose vaginal ring is available to treat hot flashes, so the hormone released from this higher dose ring clearly reaches sufficient levels to affect other parts of the body besides the genital area. The vaginal ring remains in place for 12 weeks, after which it can be changed by either the woman herself or her physician. The long-term safety of estrogen rings is not yet clear, but there is a low level of absorption of the hormone into the bloodstream with use of the vaginal estrogen ring.
Bioidentical hormone therapy
There has been increasing interest in recent years in the use of so-called "bioidentical" hormone therapy for perimenopausal women. Bioidentical hormone preparations are medications that contain hormones that have the same chemical formula as those made naturally in the body. The hormones are created in a laboratory by altering compounds derived from naturally-occurring plant products. Some of these so-called bioidentical hormone preparations are U.S. FDA-approved and manufactured by drug companies, while others are made at special pharmacies called compounding pharmacies, which make the preparations on a case-by-case basis for each patient. These individual preparations are not regulated by the FDA, because compounded products are not standardized.
Advocates of bioidentical hormone therapy argue that the products, applied as creams or gels, are absorbed into the body in their active form without the need for "first pass" metabolism in the liver, and that their use may avoid potentially dangerous side effects of synthetic hormones used in conventional hormone therapy. However, studies to establish the long-term safety and effectiveness of these products have not been carried out.