The maker of Viagra has found that the deaths of six men who took the impotence drug were the result of heart attacks or strokes after sex or were linked to heart medication.
Pfizer Inc. said it plans no changes to labels on the drug. The label already warns against combining Viagra with nitrates, found in some heart medications, and of cardiac risk associated with sex.The label advises doctors to consider those factors before prescribing the drug.
"Pfizer believes that the information available in the cases does not suggest any risk to patients which is not already described in the product label or known for the population being treated with Viagra," the company said in a statement Thursday.
More than 1 million men have filled prescriptions for Viagra since the drug was approved by federal regulators March 27. Pfi-zer estimates that 85 percent of those patients are at least 50 years old.
Pfizer said it concluded that three of the deaths were heart attacks or strokes following sexual activity, while the others were attributed to the combination of Viagra and nitrates. Nitrate medications are often used to treat chest pain in heart patients, and the combination of nitrates and Viagra can cause large, sudden drops in blood pressure.
Pfizer reported the deaths to the Food and Drug Administration but has not released specifics of each case.
At least some of the men who died had serious conditions such as diabetes or high blood pressure. The three whose deaths were cardiovascular - heart attacks or strokes - were over age 60, Pfizer said.