Erectile dysfunction drugs may reduce fertility but help depression
Two recent studies reveal that drugs belonging to the phosphodiesterase type-5 inhibitor class have both negative and positive side effects.
Researchers from Belfast say that sildenafil (Viagra) may affect a man’s
fertility, reducing his chances of starting a family. They incubated
45 samples of semen with sildenafil or a control solution and found that
the samples treated with sildenafil had increased motility. Active drug
also seemed to speed up the acrosome reaction, which normally occurs
when the sperm reaches the egg.
The reaction releases digestive enzymes that break down the egg’s
outer layer, allowing the sperm to penetrate. The researchers say that
if these enzymes are released too early, the sperm are rendered infertile.
Presenting the results at the annual British Fertility Society meeting
last week, David Glenn, of Queen’s University, commented: “Nearly
half of licensed fertility units in the UK currently use sildenafil to
assist patient semen production. Our study raises
questions about the drug’s use in assisted
reproduction.”
A spokeswoman for Pfizer, manufacturer of Viagra, told The Journal that
there is no clinical evidence that Viagra decreases male fertility. “In
fact, Viagra has helped men father children who may not have otherwise
due to fertility problems caused by a multitude of conditions such as
premature ejaculation, spinal cord injury and other serious conditions.”
She added that previous studies have demonstrated mixed results. “What
occurs in the laboratory, however, does not necessarily translate to
what happens in humans.”
It is not all bad news though. A
second study showed that vardenafil (Levitra) can improve symptoms of
depression. Researchers from Bayer compared the effects of the drug with
placebo in 280 men with erectile dysfunction and untreated mild major
depressive disorder. They found that the drug improved depression scores
(as measured by the Hamilton Depression Scale) as well as having positive
effects on erectile function.
The data were presented at the European Association of Urology congress
held in Vienna last month. |
The
Pharmaceutical Journal
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