Still, Curhan said, the findings contain an important message for patients.
''Commonly used medications available over the counter at a drugstore may have adverse effects as well as beneficial effects," said Curhan, an associate professor at Harvard Medical School.
The researchers, whose study was released yesterday, first reported on a possible link between painkillers and high blood pressure in 2002.
Federal regulators earlier this year required that another class of pain relievers, nonsteroidal anti-inflammatory drugs, carry warning labels because of the risk of heart problems. Those include ibuprofen, sold as Advil and Motrin, and naproxen, sold as Aleve. Many had turned to those painkillers following problems with prescription drugs, such as Vioxx.
The new study also found that those nonsteroidal anti-inflammatories -- commonly known as NSAIDs -- appeared to increase blood pressure. Aspirin did not appear to pose a problem.
''If you're taking these over-the-counter medications at high dosages on a regular basis, make sure that you report it to your doctor and you're checking your blood pressure," said Dr. Christie Ballantyne, a cardiologist at the Methodist DeBakey Heart Center in Houston who had no role in the study.
The research found that aspirin remains the safest medicine for pain relief. It has long been known to reduce the risk of cardiovascular problems and was not included in the government's requirement for stricter labels for NSAIDs.
The study involved 5,123 women participating in the Nurses Health Study at Harvard Medical School and Brigham and Women's. None had high blood pressure when it began.
''It certainly sets the basis for more studies," said Dr. Stephanie Lawhorn, a cardiologist at St. Luke's Mid America Heart Institute in Kansas City.
