Study Links Painkillers, Hypertension

Common over-the-counter painkillers may be linked to an increased risk of high blood pressure in women, according to a new study by researchers at Harvard Medical School (HMS) and the Harvard School of Public Health (HSPH).

The study, published in yesterday’s Archives of Internal Medicine, concluded that nonsteroidal anti-inflammatory drugs, found in Advil and Motrin, among other painkillers, and acetaminophen, an ingredient in Tylenol, “were significantly associated with increased risk of hypertension.”

Aspirin use was not associated with such a risk.

But the study’s authors urge caution in interpreting the study’s results.

One of the authors, Walter C. Willett, said the study’s findings do not necessarily recommend patients stop using specific medications.

“If someone is taking these painkillers on a regular basis, I don’t think they should just stop taking them,” said Willett, an HSPH professor of epidemiology and nutrition. “[But] it would be a good idea to discuss it with their doctor.”

The study tracked 80,020 female nurses, ages 31-50, who had no previous history of hypertension.

The women were surveyed in 1995 about their use of painkillers, and hypertension data was collected two years later.

During that two-year period, 1,650 of the women developed high blood pressure, according to the study.

Women using nonsteroidal anti-inflammatories 22 or more days each month had an 86 percent greater chance of developing hypertension, according to the study.

The study also found that women using acetaminophen that regularly were twice as likely to develop high blood pressure as non-users.

But makers of Tylenol warn that the study findings may not be reliable.

“These study results must be viewed with great caution,” said Mark Gutsche, spokesperson for McNeil Consumer & Specialty Pharmaceuticals, the maker of Tylenol products. “These results are not consistent with fairly overwhelming data from well-controlled clinical trials.”

Gary C. Curhan, assistant professor of medicine at HMS who is the study’s primary author, said that self-reported nature of hypertension diagnoses could be one variable in the study.

“[Self-reported diagnosis] certainly is one source of potential misclassification,” said Curhan, who added that self-reported diagnosis has nevertheless proved reliable in other studies.

The study’s subjects were asked to report the frequency of painkiller use, but not the number of tablets taken per day or dosage, another potential variable, according to the study.

The researchers currently do not have information on how long the medications have to be used before the risk of hypertension increases.

Ibuprofen and other nonsteroidal anti-inflammatories may cause hypertension by inhibiting the production of prostaglandins, substances that improve blood flow, and by increasing sodium retention, the study said.

The link between ibuprofen and hypertension is a well-established one, said Randall M. Zusman, director of the division of hypertension and vascular medicine at Massachusetts General Hospital and a HMS associate professor of medicine.

“I strongly advise my patients not to take [ibuprofen] chronically,” said Zusman, who had not seen the report. “Any patient with high blood pressure should be vigilant about taking anti- inflammatories. In general, no one should take drugs they don’t need.”

Acetaminophen may also inhibit prostaglandin production, according to the study. No definite conclusion explaining the drug’s effect on blood pressure was reached.

“There’s no scientific mechanism by which acetaminophen can cause increased blood pressure,” said Gutsche.

Given the ready availability of the painkillers studied, possible associations with hypertension merit further study, the researchers said.

The study’s results “definitely need to be replicated by other independent groups,” said Curhan.

“It’s not a matter to be alarmed over,” but is something to be aware of, said Meir J. Stampfer, an HSPH professor of epidemiology and nutrition and one of the study’s authors.

“We’ll be exploring other populations to get a better handle on this,” he said.