US senator, Charles Grassely, says that the US Food and Drug Administration is dragging its heels in changing the labelling for Pfizer’s erectile dysfunction drug, Viagra (sildenafil), to highlight an increased risk of an increased risk of blindness amongst users.

In a letter to the FDA, Grassley, who also chairs the Senate Finance Committee, questioned why the drug’s label had not yet been changed even though a safety evaluator first recommended a label change back in March 2004, according to a Reuters report.

The issue came to a head back in May, when Pfizer said it was talking with the FDA with a view to changing the Viagra label to highlight the risk of nonanterior ischemic optic neuropathy – a type of stroke affecting the eye – even though it does not believe that the condition occurs any more frequently with Viagra than in the general population [[31/05/05a]]. Late last month, the company said that a review of the product had concluded that there was evidence of an increased risk of blindness amongst users, albeit the company has agreed to include the fact of these reports in the Viagra label to help inform physicians and patients [[28/06/05c]]. Pfizer’s chief medical officer, Dr Joseph Feczko, said: “Men taking Viagra are at no greater risk for blindness – including vision loss from NAION – than men of similar age and health not taking the medicine.”