Blood pressure drug is male contraceptive; Also, gel for women acts as potent anti-HIV agent


TORONTO -- Scientists have announced the development of two contraceptives, a pill for men and a gel for women that doubles as a potent anti-HIV agent.

At an international conference on reproductive medicine, researchers from New York said they had found that a drug widely used to control high blood pressure can also knock out sperm's ability to penetrate an egg.

Although pharmaceutical companies are reluctant to pursue the discovery, the drug holds promise on two fronts: It has been declared safe and does not affect male hormones, long a stumbling block in the development of a pill for men.

At the same time, a Minnesota researcher announced that he was beginning clinical trials of a vaginal gel that protects against pregnancy and the human immunodeficiency virus, which causes AIDS. About 90 percent of HIV cases worldwide are heterosexually transmitted.

Acquired immune deficiency syndrome is the third-leading cause of death in American women of reproductive age.

Researcher Susan Benoff stumbled upon the idea for a male contraceptive when many of her male infertility patients with normal sperm counts were unable to fertilize eggs.

Taking their medical histories, she noticed that many of the men had high blood pressure and were taking a class of drugs known as calcium channel blockers, such as Procardia by Pfizer or Cardizem by Hoechst Marion Roussel.

When the men switched to other anti-hypertensives, their fertility returned within three months.

Possible side effects are minimal -- headaches or gum bleeding -- and far less severe, Benoff said, than side effects associated with oral contraception for women.

Meanwhile, Osmond D'Cruz, director of reproductive biology at Hughes Institute in St. Paul, Minn., said Tuesday that he had formulated a compound for women that was 439 times more effective against HIV infection than nonoxynol-9 and 14 times more potent as a spermicide. The compound is a derivation of AZT, the commonly used AIDS treatment.

Human clinical trials of that compound are to begin in the next few months. The gel is expected to be on the market in two years.

Pub Date: 9/30/99

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