A company spokesman says Pfizer is talking with federal regulators about whether the impotence drug Viagra needs a new warning label.
The Food and Drug Administration today announced it's investigating 38 cases of blindness among men using Viagra and four cases among Cyalis users.
The Pfizer spokesman says there's no proof Viagra caused the condition, but the company may mention it on the label. He says men taking the drug often have high blood pressure and high cholesterol, both of which are associated with conditions that can cause blindness.
A GlaxoSmithKline spokesman says the impotence drug Levitra hasn't been linked to any reports of blindness. It works in the same way as Cialis and Viagra, but the company says each medication "is unique."
An industry expert says he doesn't expect Viagra sales to fade, since the number of cases is so small.