Diego Padro says he paid too high a price for a few days of Viagra-induced sex: a heart attack.
"Viagra changed my life, but not favourably," the 63-year-old man said after filing a £52 million lawsuit in New York state Supreme Court against the maker of the impotency treatment drug.
It is the first lawsuit against Pfizer involving the popular pill that allegedly has changed the lives of more than a million men since it appeared on the market in March.
"He was perfectly healthy, and five days after he started taking Viagra - bam," said his lawyer, Mr Ronald Benjamin.
Pfizer, which is based in New York, said Viagra is "a safe and effective medicine for erectile dysfunction when used as recommended in the approved package insert."
The drug is taken an hour before intercourse. Mr Padro suffered the attack about a day and a half after taking the last of four pills he was given by his doctor after a check-up that included a cardiogram and treadmill stress test. Mr Padro said he has diabetes but no history of heart trouble.
His doctor, Dr David Krum holz, gave him no warning about possible side effects from Viagra, Mr Padro said.
When considering whether to take Viagra, Mr Padro relied on the fact that the US Food and Drug Administration had approved the drug as safe for use without regard to age, according to the court complaint.
Mr Padro had flu-like symptoms over most of the weekend. The following Tuesday, he went to a hospital, where a cardiogram showed "that I was in the middle of having a heart attack". His lawyer said a cardiologist has linked Mr Padro's heart attack to use of Viagra. He was in hospital for eight days and still suffers from anxiety, fearing another, possibly fatal, heart attack.
At least 30 Viagra users have died since the drug hit the market. The FDA says the drug could pose serious problems for men who take nitrates, a variety of heart drug that includes nitroglycerin. The warning is printed on the label.
"My feelings are that no one needs to improve their sex life where they need to die from it," said Mr Padro.