. The FDA stressed that there was no evidence the blockbuster impotence drug, sold by Pfizer, caused the 15 deaths - and some of the reports of deaths were completely unconfirmed. More than a million men have taken the drug since it hit the market in April. The drug works to get more blood to the penis during sexual arousal, allowing a man to have an erection. "As of June 8, 1998, the FDA has received 16 unduplicated reports for Viagra in which there was a fatal outcome," the FDA said in a statement posted on its internet web page at www.fda.gov. The statement, released as the result of a Freedom of Information request, briefly describes each of the 16 cases.