Men who take over-the-counter painkillers, such as Johnson & Johnson's Tylenol, have more risk of developing high blood pressure than those who don't take the drugs, a study found.

Taking acetaminophen-based drugs such as Tylenol six to seven times a week raised the risk 34 percent, researchers said in the Feb. 27 Archives of Internal Medicine. Men who took non-steroidal anti-inflammatory pills, a category that includes Wyeth's Advil and J&J's Motrin, raised their risk 38 percent, according to the study. The figure was 26 percent for aspirin.

The drugs studied are among the most widely used pills. The medicines, except for aspirin, earlier were linked to increases in high blood pressure in women. People should exercise caution when taking the drugs, said the leader of the new study, John Forman, a doctor at Brigham and Women's Hospital in Boston.

"We are by no means saying that people with pain should not receive treatment," Forman said in an e-mail on Feb. 23. "Rather, we are highlighting potential risks associated with certain commonly used drugs."

The researchers examined questionnaires from 16,031 men without any history of high blood pressure. The men, whose average age was about 65, were asked in 2000 and in 2002 whether they used the three types of painkillers and how often.

During four years of follow up, 1,968 of the men developed high blood pressure, the researchers found. Men who weekly took 15 or more pain pills, regardless of the type, had a 48 percent greater risk of high blood pressure, compared with men who took no pills.

"While we are highlighting certain potential risks, these medications also have benefits, including pain control, and in the case of aspirin for some people, reduction in heart attack risk," Forman said.

The study, funded by the American Heart Association and the National Institutes of Health, didn't examine specific doses.

"One should not assume from this that one or two pills per week are perfectly safe," Forman said. The medicines may raise blood pressure by interfering with the ability of blood vessels to relax, he said.

Blood pressure is the force that blood exerts inside vessels. High blood pressure affects about 72 million Americans age 20 and over, according to the heart association. The condition can lead to stroke, heart attack, heart failure or kidney failure.

"Increased blood pressure is a known side effect when ibuprofen is used at higher prescription doses," said Fran Sullivan, a spokesman for Madison, New Jersey-based Wyeth, in a Feb. 23 e-mail. "We do not believe that this article will have an impact on the sales of Advil, as the product has a long track record of safe and effective use."