From a heart drug to a safe male Pill

日期:2019-03-07 08:09:02 作者:宣匠 阅读:

By Alison Motluk A DRUG for treating high blood pressure could be the key to developing a male contraceptive pill, says a scientist from New York. Nifedipine belongs to a class of drugs known as calcium channel blockers. It controls blood pressure and eases angina by interfering with the conduction of electrical signals in the muscles of the heart and blood vessels. However, in lab tests Susan Benoff of New York University and her colleagues found that treating sperm with nifedipine significantly reduced the effectiveness of receptors that help them bind to an egg during fertilisation. This means that the drug may block fertility, the researchers say. The effect might come about because the drug changes the levels of cholesterol in the membranes of the sperm. This makes the drug an ideal candidate for a male contraceptive pill, says Benoff. Unlike other male birth-control pills on the drawing board, nifedipine works without interfering with the body’s normal sex hormones. What’s more, its effect on sperm reverses after treatment stops. And because the drug has been in use for over 20 years, its safety is well established, which should ease its approval by drug authorities. Benoff wants to alter nifedipine slightly and subject it to clinical trials as a contraceptive. “Now that we know the structure of the drug we can start modifying it,” she says. But six major drugs companies have so far declined to finance the work. Corey Toal, director of scientific development at Bayer Canada in Toronto, could not confirm nifedipine’s contraceptive effect. “It has not been studied clinically in men,” he says, arguing that Bayer is not a birth control company. More on these topics: