Can Viagra cause violence?

In a controversial research review, toxicologist Harold Milman and S. B. Arnold recently raised the possibility that the drug Viagra, used to treat erectile dysfunction, may contribute to violent behavior.

Milman and Arnold uncovered 274 reports of mental side effects linked to Viagra (sildenafil), including amnesia, aggression, and disorientation. In addition, they note that the drug has been suggested as a contributing factor in 22 cases involving aggression, 13 involving rape, and 6 involving murder.

Milman notes, "Published studies [report] that sildenafil crosses the blood-brain barrier, that it exerts various biochemical and physiologic effects in the brain, and that it affects information processing." He acknowledges that his data on behavioral side effects is anecdotal, but says, "It's clear that these men are behaving abnormally."

He concludes, "It is recommended that before prescribing sildenafil for erectile dysfunction, clinicians should caution their patients and their partners on the possibility of neurologic, emotional, or psychological disturbances; amnesia or loss of consciousness; or aggressive behavior."

The study's conclusions are challenged by several scientists, including Kevin McKenna who says studies of rodents suggest that Viagra would be likely to reduce aggression rather than increasing it.

"Neurologic, psychological, and aggressive disturbances with sildenafil," H. A. Milman and S. B. Arnold, Annals of Pharmacotherapy, Vol. 36, No. 7-8, July-August 2002, 1129-34. Address: Harold Milman, ToxNetwork.com, Rockville, MD 20853-2345.

"Scientists debate possible Viagra-aggression link," Todd Zwillich, Reuters, December 6, 2002.