Medications

Medications

Hormone Replacement Therapy (HRT)

Doctors used to believe that HRT could help reduce the risk of heart disease and other health risks in addition to treating menopausal symptoms. The results of an important study, called the Women's Health Initiative (WHI), led doctors to revise their recommendations regarding HRT.

The WHI, started in 1991, enrolled 161,809 women between the ages of 50-79 in 40 different medical centers. Part of the study was intended to examine the health benefits and risks of hormone replacement therapy, including the risks of breast cancer, heart attacks, strokes, and blood clots.

In 2002, one component of the WHI, which studied the use of estrogen and progestin in women who had a uterus, was stopped early because the health risks exceeded the health benefits. The main reason for stopping the estrogen-progestin study was a 26% increase in breast cancer. This combination therapy study also showed an increased risk for heart attack, stroke, blood clots, and dementia. There was a reduced risk for colorectal cancer and bone fractures but these benefits did not outweigh the considerable risks.

In 2004, a second component of the WHI, which studied estrogen-only therapy in women who no longer have a uterus, was stopped early. This was primarily because of an increase in the risk for strokes and blood clots. The study also found the estrogen-only therapy had no effect on heart attack or colorectal cancer risk. An update in 2006 suggested that estrogen-only therapy does not increase breast cancer risk over the short term (average 7 years) but may increase risk when taken for a longer time (15 years or more).

While the WHI study suggests that HRT should not be prescribed for prevention of chronic diseases, many doctors still accept its use for short-term treatment of moderate to severe hot flushes and other menopausal symptoms, and in women undergoing premature menopause for medical or other reasons. Current guidelines recommend using the lowest possible dose for the shortest duration of time.