Prostate disease (cancer) is extremely nasty: you have to go to the toilet countless times daily. Surgery can also be very tricky: it can leave you impotent. Drugs would be a measure against prostate condition, but some researches say they could induce impotence, too.

A new research made at Southwest Oncology Group says that at least finasteride does not. The research team surveyed over 17,000 subjects, 55 and older, for seven years. The research showed that men given finasteride had on average a more serious dysfunction than those given a placebo, but that small effect decreased over the seven years.

Physicians usually warn that sexual dysfunction could occur when taking into consideration this drug.

Finasteride is an FDA-approved drug against benign prostatic hyperplasia, but it does not reduce the risk of prostate cancer. "The study's large sample and long follow-up period allowed researchers to examine whether or not finasteride negatively affected sexual function and, if so, whether this effect was lasting," said lead author Dr. Carol Moinpour, of the Fred Hutchison Cancer Research Center in Seattle.

Finasteride is a chemical that stops the proliferation of prostate gland cells, preventing prostate cancer in men aged 55 and older, by 25 %, as showed by a 2003 trial made on over 18,000 men.

The new research proposed to measure how many men reported sexual dysfunction, and how the problems varied over time. Previous researches showed that some men on finasteride reported lower sex drive, impotence and decreased sexual function, but these were short-term surveys which did not take into account other factors, like age and individual variation.

The new trial surveyed the volunteers three times in the first year and then annually in the next 6 years. "Was this average decrease (in sexual function) an important difference. We concluded it was not. There were much larger differences due simply to individual variation among men in the trial.", Moinpour said.

"The study suggests that finasteride will cause little or no sexual dysfunction for most men who decide to take it," the researchers explained.