Viagra may decrease ability to smell

NEW YORK (Reuters Health) - Higher doses of Viagra (sildenafil) may impair the ability to smell, which is possibly related to an increase in nasal congestion, German researchers report in The Journal of Urology.

A team led by Dr. V. Gudziol at the University of Dresden Medical School studied 20 healthy, young male volunteers who received Viagra, at a 50- or 100-mg dose, or inactive "placebo" and then were exposed to an odor-dispensing device.

The researchers tested the subjects' odor detection threshold, odor discrimination and odor identification ability.

They found that the 100-mg dose caused a drop in smelling or "olfactory" ability, specifically odor discrimination and odor threshold, compared with placebo. The 50-mg dose, by contrast, had no effect on olfactory function.

"In our subjects, the most likely reason for impaired...olfactory function was nasal congestion" brought on by Viagra, the authors write. They note that, while it was not evaluated in this study, previous reports have linked Viagra with a drop in nasal airflow.

SOURCE: The Journal of Urology, January 2007.