Despite advice that people with kidney disease avoid non-steroidal anti-inflammatory drugs (NSAIDs), a new study suggests that they may be using the painkillers even more often than other people do.
Researchers found that of more than 12,000 Americans in a government health survey, those with moderate to severe kidney disease were more likely to be using NSAIDs: five percent currently were, versus 2.5 percent of adults with healthy kidneys and 2.5 percent of those with mild kidney disease.
What's more, two-thirds of NSAID users with more-serious kidney disease had been taking the painkillers for at least a year.
Some studies, though not all, have suggested that the painkillers may worsen kidney disease. So experts recommend that people with any degree of chronic kidney dysfunction avoid NSAIDs (except for aspirin, which is usually taken for its heart benefits), and instead reach for acetaminophen to treat aches and pains.
It's not clear what kinds of conditions the people in this study with kidney disease were treating with NSAIDs.
In some cases, the NSAIDs were prescribed -- about 10 percent of the time among users with moderate to severe kidney disease.
People with kidney disease are also likely to have other health problems, including painful arthritic conditions. So in some cases, a doctor might have weighed the risks of NSAIDs against the benefits -- easing chronic pain -- and decided to prescribe the drug, according to lead researcher Laura Plantinga, of Emory University in Atlanta.
In other cases, though, people with kidney disease may not have been aware that NSAIDs, including over-the-counter versions, are to be avoided.
"People sometimes assume over-the-counter medications are safe," Plantinga said in an interview.
The bottom line for people with kidney disease is to be aware that all medications can have risks, according to Plantinga. And it's always a good idea, she added, to ask your doctor before taking any drug.
The findings, which appear in the Annals of Family Medicine, are based on information from 12,056 U.S. adults who took part in a government health study. They gave blood and urine samples to have their kidney function tested and answered questions on their medication use.
Overall, nine percent had mild kidney disease and 11 percent had moderate to severe disease.
And for most of them, that was news. Nearly 96 percent of participants with mild kidney disease had been unaware of it. The same was true of nearly 90 percent with moderate to severe kidney dysfunction.
Such a lack of awareness is so common, Plantinga said, because kidney disease usually causes no symptoms until it is advanced -- when problems like fatigue, frequent urination, appetite loss, darkening of the skin and swelling in the hands and feet may show up.
NSAID use, however, was just as frequent among people who did know they had kidney disease. About four percent were currently taking an NSAID, as were four percent of those who had been unaware of their kidney problems.
The most common causes of chronic kidney disease are high blood pressure and diabetes, and people with those conditions should have their kidney function periodically tested. If you have not had that testing done, or aren't sure if you have, Plantinga said, ask your doctor about it.