A few hours later, doctors diagnosed the problem — rhabdomyolysis, a potentially fatal precursor to kidney failure. Though dehydration and overexertion contributed to Ehret’s condition, doctors told her that the 12 ibuprofen pills she’d taken during the 24-hour race had pushed her kidneys into the danger zone.
Kidney pain can accompany failure, or it can come so fast you don't even feel it.
When used properly, over-the-counter pain medications can be a godsend. Acetaminophen (Tylenol) can tame many pains. And non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen, aspirin, and naproxen can reduce pain and swelling in the first few days following an acute injury like an ankle sprain. The trouble comes, doctors say, when people, like Ehret, misuse these drugs. “A couple of ibuprofens really helped, so I figured more was better,” Ehret says. Indeed, many runners treat anti-inflammatory drugs like “vitamin I,” says pharmacologist Joe Graedon, co-author of The People’s Pharmacy book series. “They think, I’m putting my body through a lot, so I’ll just dose up on ibuprofen, without appreciating how potentially dangerous this drug can be.”
Runners beware Runners may think that as long as they don’t go overboard like Ehret, they’ll be safe. But experts say the benefits of popping even one pill before a 10K don’t outweigh the risks. NSAIDs inhibit prostaglandins, hormones that help normalize blood flow to the kidneys. Mix an NSAID with physical exertion and dehydration, and you can overwhelm your kidneys.
What’s more, NSAIDs can bump up your blood pressure, and when you add this to the natural rise that occurs when you exercise, “suddenly you have two things increasing your blood pressure,” Graedon says. If you already have high blood pressure, “you could have a mini stroke or a heart attack,” he says. NSAIDs also block an enzyme called cyclooxygenase (COX) that normally protects the heart, and this might explain why many NSAIDs, including ibuprofen, may raise the risk of heart attack.
Some forms of COX also protect the stomach lining from digestive acids, so when an NSAID blocks this enzyme, you may experience nausea, diarrhea, intestinal bleeding, and cramps. When used during a marathon or ultra, NSAIDs also seem to boost the risk of hyponatremia, an electrolyte imbalance that can cause the brain to swell. “It’s something you can die of during a race,” says Martin Hoffman, M. D., director of research at the Western States Endurance Run.
Many runners believe that NSAIDs increase their pain tolerance, but studies contradict this notion. In 2005, David Nieman, Dr. P.H., director of the human performance lab at Appalachian State University in Boone, North Carolina, examined ibuprofen use at Western States. About 70 percent of the racers said they took it to help them manage the discomfort of racing. But when he measured pain and muscle soreness in these pill poppers, he found no reduction compared with nonusers. Worse, ibuprofen takers had more inflammation. “There’s no good reason to use ibuprofen during a race,” Nieman says. “There are too many potential negatives.” Any pain and inflammation that turns up while running is not something you should medicate but a signal that it’s time to reevaluate your training regimen, he says.
Watch the dosage For relief during or after exercise, Hoffman recommends acetaminophen since it works via a different mechanism than NSAIDs, and the drug doesn’t have the side effects associated with aspirin or ibuprofen. “It’s a relatively safe drug, and it doesn’t present problems with the kidney or gut,” he says.
But watch the dosage. While it’s safe at recommended doses, acetaminophen can be toxic to the liver, especially when mixed with alcohol. “You can hit the tipping point pretty fast with acetaminophen,” says Graedon. Acetaminophen overdose is the most common cause of acute liver failure in the United States, in part because the drug is found in many over-the-counter cold and allergy medicines, so it’s easy to overdose if you take one of these drugs with Tylenol.
And limit the number of days you take meds. “Studies show that NSAIDs can impair the healing process for soft-tissue injuries, so you should never use them long-term for injuries,” says Hoffman.