French Study Suggests That Skin Patches Are a Safe Alternative for HRT

The use of skin patches instead of pills may not increase the risk of blood clotting in the legs or lungs, even for those with a history of blood clots, a new study reports.

The report, published in the journal Menopause, goes on to say skin patches may even be safer than pills for women looking to use hormone replacement therapy (HRT) to treat uncomfortable menopause symptoms.

HRT use declined drastically in 2002 when a after an extensive U.S. clinical trial found that women on estrogen-plus-progesterone pills had elevated risks of heart attack, blood clots, stroke and breast cancer compared to placebo users.

Until then, HRT had been widely given out by doctors to prevent heart disease and osteoporosis. This is no longer the case.

Despite this, HRT is still the most reliable way to alleviate menopausal hot flashes, so a significant number so some women with severe symptoms decide to use it. However, because of the perceived risks, experts suggest that women use HRT at the lowest possible dose and for the shortest time possible.

There is now an increasing amount of evidence, though, that low-dose patches may carry less risk than pills. A number of studies have found that, compared to pills, patches don't raise the risk of a first-time venous thromboembolism (VTE) - blood clots, typically in the leg veins or the lungs.

A British study earlier this year produced results that suggested that women using low-dose patches for hormone therapy suffered no increased risk of stroke or varicose veins than those not on HRT. Women on hormone pills or high-dose patches, however, did have a higher stroke risk than non-users.

Strokes are most often caused by clots that disrupt blood flow to the brain.

In the new study, researchers investigated hormone therapy and the risk of repeat VTEs in women who had previously suffered this condition.

From the 1,023 women studied, 103 started used hormone patches to treat menopausal symptoms after stopping their VTE treatment, which typically involves many months on anti-clotting medicines. Another ten subjects used oral HRT, while the rest did not use any hormone replacement.

Over a period averaging 6.5 years, 77 women (1% per year) had a repeat blood clot. For women using hormone patches, the risk was found to be no greater than it was for women not on HRT.

Out of the 103 women who chose to use the patches, six of them had a repeat blood clot. In comparison, two of the 10 who used hormone pills suffered a repeat clot. When other factors were considered, such as the women's weight and age, those on pills showed a six-fold greater risk of a repeat blood clot compared to those women who did not use hormone therapy.

Results suggest that for all women, even those at high risk of VTE, hormone patches may not further that risk.

Researchers believe that hormone patches may be less risky than pills because of the way they work. Unlike oral hormones, those delivered by the skin patch bypass the liver, and so may not promote the formation of clot-promoting proteins in the blood.

This study is the first to suggest that high-risk women who use hormone patches have no extra risk of repeat blood clots.

However researchers said that it remains a personal decision for women to make after talking with their doctor about the risks and benefits.