If you’re currently taking a diuretic and a renin-angiotensin system (RSA) inhibitor for hypertension, researchers from the University of Waterloo warn that taking ibuprofen could be a very harmful combination. Scientists report combining the three drugs can result in acute kidney injury among certain medical profiles. In some cases, these kidney injuries can be permanent.

Available under a wide variety of pharmaceutical brand names, diuretics and RSA inhibitors — such as an angiotensin converting enzyme (ACE) inhibitor or angiotensin receptor blockers — are routinely prescribed together to help treat high blood pressure. Ibuprofen, on the other hand, is a widely available over-the-counter painkiller.

Researchers used a series of computer-simulated drug trials to reach these conclusions. This strategy allowed them to model the interactions between the three drugs, as well as any impact on the kidneys.

“It’s not that everyone who happens to take this combination of drugs is going to have problems,” says Anita Layton, professor of applied mathematics at Waterloo and Canada 150 Research Chair in mathematical biology and medicine, in a university release. “But the research shows it’s enough of a problem that you should exercise caution.”

Dehydration plays a major role in kidney damage

Human clinical trials can take months or longer to produce results. Computer-simulated drug trials, however, are much faster. So, Prof. Layton and her team use their expertise in math and computer science to create computer-simulated drug trials, affording medical practitioners a much earlier indication of any potential drug interaction problems.

This time around, their findings apply directly to many, many people currently taking drugs for their blood pressure. Such individuals may take an ibuprofen and have no idea they are putting their kidneys at risk.

“Diuretics are a family of drugs that make the body hold less water,” Prof. Layton concludes. “Being dehydrated is a major factor in acute kidney injury, and then the RAS inhibitor and ibuprofen hit the kidney with this triple whammy. If you happen to be on these hypertension drugs and need a painkiller, consider acetaminophen instead.”