Aug 6, 2006
Heart drugs are proving rather useful to pharma companies hoping to find lucrative treatments of another kind of disorder, that maybe involves the heart, but mostly involves the loins.
A heart drug that went into clinical trials in the 1990s has become the linchpin for efforts to develop a medication to treat female sexual arousal disorder (FSAD), researchers are reporting. An estimated 40 percent of women have FSAD or another form of female sexual dysfunction, the difficulty or inability to find satisfaction in sexual expression.
Compounds that sustain the activity of vasoactive intestinal peptide (VIP) are a major target of drug research efforts. VIP controls blood flow to the vagina, and decreased blood flow is believed to be one factor in female sexual dysfunction. VIP is degraded in the body by several enzymes, including an enzyme called NEP. Blocking NEP thus allows VIP to continue working.
David Pryde and colleagues at Pfizer in the UK (the company that brought us Viagra) began work with Candoxatril, a powerful NEP inhibitor tested in the 1990s for chronic heart failure. By re-engineering Candoxatril’s molecular structure, they developed a compound with the key actions needed for an FSAD drug.
The new compound blocks NEP, takes effect rapidly, and continues having an effect for a relatively short time. “The compound demonstrates excellent efficacy in a rabbit model of sexual arousal and was expected to be similarly efficacious in humans,” the researchers state in the Journal of Medicinal Chemistry. The compound is undergoing clinical evaluation as a potential treatment for FSAD.