The Advil label includes a warning to consumers to take a maximum of six tablets daily and for no more than 10 days, he said.

The new study relied on data reported by patients and didn't control for conditions such as lifestyle and health that may have contributed to high blood pressure, said Bill Pearse, a spokesman for the McNeil Consumer Healthcare unit of New Brunswick, New Jersey-based J&J, in an e-mailed statement today.

"The safety and efficacy of acetaminophen at recommended doses has been established through more than 50 years of clinical use and scientific investigation," he said. "In addition, published studies of acetaminophen used for as long as two years have not demonstrated an increased risk for these cardiovascular events."

Nonsteroidal anti-inflammatory drugs, or NSAIDs, are used to relieve some arthritis symptoms such as inflammation, swelling, stiffness and joint pain, according to the National Institutes of Health. Advil and Motrin are a form of NSAID called ibuprofen. Another type, naproxen, is sold as Aleve by Bayer AG of Leverkusen, Germany.

Aspirin is used to reduce fever and relieve mild to moderate pain, to prevent heart attacks in people who have had a previous attack or who have chest pain, and to prevent certain kinds of strokes. Acetaminophen is used to relieve mild to moderate pain, and to lower fever.

In another development, the heart association said in a statement published today in the journal Circulation that doctors should change the way they prescribe medicines for pain in patients who have heart disease or are at risk for it.

The association said doctors have been prescribing newer NSAIDs, called Cox-2 inhibitors, before trying other treatments. These drugs include Celebrex, made by New York-based Pfizer Inc.

"For chronic pain in patients with known heart disease or who are at risk for heart disease, these drugs should be the last line of treatment," wrote Elliott Antman, the statement's lead author and a professor at Harvard Medical School and Brigham and Women's Hospital in Boston. "We advise physicians to start with non-pharmacologic treatments such as physical therapy and exercise, weight loss to reduce stress on joints and heat or cold therapy."

U.S. regulators require Cox-2 inhibitors and older NSAIDs to carry a warning, saying the pills may increase risk of heart attacks. Merck & Co., based in Whitehouse Station, New Jersey, in 2004 pulled the Cox-2 inhibitor Vioxx from the market after studies showed increased cardiovascular risk.