Like Viagra before it, a drug once studied to treat heart problems may help treat sexual dysfunction. But this time it’s being tested exclusively for women.

A new study shows that a modified version of the experimental heart drug Candoxatril was effective at increasing blood flow to the vagina in animal tests.

If further research confirms these results in humans, the drug may be used to treat female sexual arousal disorder (FSAD).

Researchers say an estimated 40 percent of women suffer from FSAD or other forms of sexual dysfuction, such as low libido or pain during intercourse.

Candoxatril went into clinical trials in the 1990s as a heart failure medication but has since become the focus of efforts to develop a medication to treat female sexual arousal disorder.

How the Drug Works

Candoxatril is one of several compounds that targets levels of vasoactive intestinal peptide (VIP), which controls blood flow to the vagina. Researchers say decreased blood flow to the vagina is thought to be a key factor in female sexual arousal disorder.

An enzyme called NEP degrades VIP in the body, and Candoxatril works by blocking NEP.

In a new study, published in the Journal of Medicinal Chemistry, researchers altered the molecular structure of Candoxatril in order to focus the drug to treat female sexual arousal dysfunction.

In animal tests, researchers at Pfizer Global Research and Development in the U.K., found the new compound effectively blocked NEP, took effect quickly, and the effect lasted for a relatively short time.

They say the results suggest that the drug might have similar effects in humans, but further research is needed.

By Jennifer Warner, reviewed by Louise Chang, MD

SOURCES: Pryde, D. Journal of Medicinal Chemistry, July 13, 2006; vol 49: pp 4409-4424. News release, American Chemical Society.