According to a new U.S. study women who take higher doses of common, over-the-counter painkillers, such as Ibuprofen and even Tylenol, have higher blood pressure than women who do not.
The study monitored two groups of women, who were followed for three to four years, to see which ones developed high blood pressure.
It was found that only aspirin did not raise the risk of high blood pressure among the women.
The researchers said their findings, support a growing list of research that suggests all painkillers, both prescription and non-prescription, have some health risks and should be used carefully.
This list includes Acetaminophen or Paracetamol, sold by Johnson & Johnson under the brand name Tylenol.
Dr. John Phillip Forman of Harvard Medical School and Brigham and Women's Hospital in Boston, who led the study, says that women who took 500 milligrams or more of Acetaminophen per day, on average, were almost twice as likely to develop high blood pressure as women who did not use Acetaminophen.
It was also found that older women, from age 51 to 77, who used an average of 400 mg or more per day of Ibuprofen, were around 80 percent more likely to develop high blood pressure, compared to older women who did not use this drug.
While younger women, ages 34 to 53, who used more than 400 mg a day of Ibuprofen had a 60 percent higher chance of developing high blood pressure.
Forman and colleagues, in their research, studied one group of 1,903 women aged 51 to 77 and a second group of younger women aged between 34 and 53.
At the outset the women did not have high blood pressure but were regularly questioned about various aspects of their health and lifestyle, including what drugs they took, and monitored.
The study is especially important today as prescription drugs called COX-2 inhibitors have also been shown to raise the risk of blood pressure, stroke and heart attack, and many now carry warnings.
As a result patients are turning to over-the-counter alternatives, despite evidence that these can cause gastrointestinal bleeding and can also raise blood pressure.
Apparently Forman is not advocating that these medications be abandoned, as he says that people with chronic pain need to be able to treat their pain.
But he says, because people see these drugs on the shelf, available without a prescription, they assume that they have no risks and are completely safe.
The researchers found that whether the women used the drugs for headache, arthritis or other aches and pains, the findings remained the same.
This might possibly explain why high blood pressure, which itself raises the risk of stroke, heart attack and heart failure, is so common in the U.S.
Even though aspirin has been shown to prevent heart disease, the research is unclear on the other non-steroidal anti-inflammatory drugs or NSAIDS.
But although Acetaminophen was not believed to affect heart risk either way, Forman's team did note that Acetaminophen and NSAIDS can affect endothelial function, an altering of the healthy workings of the linings of blood vessels.
The researchers say that NSAIDS, apart from aspirin, do this by affecting compounds produced in the body called prostaglandins, and although aspirin also inhibits prostaglandin synthesis, it has not been associated with endothelial dysfunction, and might in fact improve endothelial function.
This has apparently been documented in patients with atherosclerosis.
The study is published in the journal Hypertension.