What Is Premphase?
) is a prescription medication that contains a mixture of natural estrogen hormones (the same hormones in Premarin®
), along with a progestin hormone. Premphase is only approved for women who still have a uterus (who have not had a hysterectomy). This hormone medication is approved the following uses:
- Preventing osteoporosis in postmenopausal women
- Treating moderate-to-severe hot flashes due to menopause
- Treating moderate-to-severe itching, burning, or dryness in or around the vagina due to menopause.
Who Makes It?
Premphase is made by Wyeth Pharmaceuticals, Inc.
How Does Premphase Work?
This medicine is a mixture of natural equine (horse) estrogens, combined with a progestin hormone (medroxyprogesterone). It helps relieve menopausal symptoms by replacing the estrogen and progesterone that the ovaries no longer produce.
Because estrogen helps keep the bones strong, the decrease that occurs during menopause causes a significant weakening of the bones, often resulting in osteoporosis. By providing estrogen, Premphase can help prevent these menopause-related bone changes.
Medroxyprogesterone (a progestin) is added to Premphase because giving estrogens without a progestin to postmenopausal women can increase the risk of cancer of the lining of the uterus. Of course, this applies only to women who still have a uterus (who have not had a hysterectomy). For women without a uterus, the medroxyprogesterone component is usually considered unnecessary.
Only the last 14 tablets in each pack of Premphase contain medroxyprogesterone, while all 28 tablets contain estrogen. Taking the medroxyprogesterone for only half a cycle usually causes regular withdrawal bleeding, similar to a normal monthly period.