VIP TREATMENT FOR IMPOTENCE

Things are looking up for sufferers of impotence, following the development of a new, user-friendly treatment by researchers at the Weizmann Institute in Israel. Clinical trials of the new topical treatment, developed jointly by the Institute's department of organic chemistry and Tel Aviv University's Sackler School of Medicine, should begin shortly.

The treatment is based on a salve formulation of vasoactive intestinal peptide (VIP), which in its injectable form has already been shown to stimulate sexual behavior in rats with reduced masculine function. The evidence for a role of VIP in impotence comes mainly from the following facts: it ordinarily is found in the male reproductive organ; its levels increase upon sexual arousal; and its levels drop significantly in some men who suffer from impotence.

The collaborative efforts to explore the therapeutic potential of this peptide began nearly seven years ago, and in 1989 the beneficial effects of the injectable form in rats were demonstrated. While these effects were encouraging, the treatment in that form would offer little clinical advance over existing treatments. Currently, in patients who do not respond to psychological counselling, erection can be achieved via the intrapenile injection of vasoactive drugs such as papaverine (with or without phentolamine), but research suggests that while this is highly effective, compliance drops rapidly within a few months, presumably because of social issues and the inconvenience. In intractable cases, prosthetic implants may provide benefit.