Older men who take Viagra risk suffering a severe heart attack even if they seem completely healthy, a new study suggests.
Doctors investigating the case of a 65-year-old man who had a heart attack after taking Viagra concluded that the anti-impotence drug was the cause. The man, prescribed Viagra by a doctor in the United States, began to experience acute chest pain half an hour after taking a single 50mg tablet.
In hospital, an electrocardiogram showed that he had suffered a severe heart attack. The man was treated and made a full recovery.
A report on the case in The Lancet medical journal, published today, said the man had no high blood pressure, diabetes, or previous history of heart disease. He did not smoke and consumed only about five alcoholic drinks a week.
The attack could not have been triggered by sexual exertion - a recognised heart attack hazard - because he had not made any attempt to have intercourse in the 30 minutes after taking the drug.
Investigator Dr J. Feenstra, from Erasmus University Medical School, Rotterdam, and colleagues from the Netherlands and Dutch West Indies, said they could not rule out pre-existing coronary-artery disease.
But they wrote: "The close temporal relation between ingesting sildenafil (Viagra) and onset of severe chest pain due to acute mycardial infarction (heart attack) in a patient without a history of previous chest pain or risk factors for cardiovascular disease . . . suggests that sildenafil was causally related to the acute mycardial infarction.
"Since the chest pain occurred before any attempt at sexual intercourse was made, sexual exertion cannot be regarded as a precipitating factor."
In the US, where Viagra is widely available on prescription, there have been 69 reported deaths of men who have taken the drug. The EU regulating authority decided that these were not sufficient reason to withhold it.