When something hurts, most Americans open their medicine cabinets and pop a few capsules, tablets or gel-caps.
Acetaminophen, aspirin, ibuprofen, naproxen: More than 80% of us report using these four main over-the-counter analgesics, according to the market research firm Mintel. Two-thirds of us keep stashes on hand, not just at home but also at work, in our handbags or in the car. And about half of us have multiple bottles available, just in case.
All that pill popping certainly affects our health — and not always for the better. Used correctly, over-the-counter analgesics can help with acute aches and pains. Even more enticing, growing evidence suggests that some of them might also help fight Alzheimer's and Parkinson's disease, as well as heart attacks and some cancers.
But there are real risks. It's easy to overdose, with dangers that include stomach upset, organ failure, strokes, even death. And the safe upper limits may vary from one person to the next, depending on body size, genes and prior health conditions.
Even healthy people can get themselves in trouble by thinking that if a little bit helps a little, a lot will help more. For some groups, including serious athletes and people with migraines, new evidence suggests that taking painkillers the wrong way or at the wrong time can do the opposite of what users took them for in the first place — create pain.
As data roll in about both the benefits and risks of over-the-counter painkillers, experts say the only good advice for everyone is to think twice before taking them.
"They are powerful drugs that are safe when taken as directed," says Janet Engle, a pharmacist at the University of Illinois at Chicago and a member of the Non-prescription Drugs Advisory Committee at the U.S. Food and Drug Administration. "If you don't take them as directed — and something like 50% of patients don't — you can get into all kinds of issues."
Consumers may be glad to know that over-the-counter painkillers work better than sugar pills in trials, though placebos do have some effect. A 2004 study in the Journal of Rheumatology, for example, found a 30% to 45% reduction in pain symptom scores in knee osteoarthritis patients who took either naproxen or ibuprofen, compared with a 20% to 25% improvement for those who received placebos.
Many times, in fact, over-the-counter painkillers work as well as a group of anti-inflammatory medications called Cox-2 inhibitors, which are prescription only.
It's not clear whether any one painkiller works better than the others for all people or for all types of pain: Scientists haven't done many head-to-head comparisons. And since all bodies and metabolisms are different, one drug might work best for one person while a different one works best for another, says Wayne Nicholson, a clinical pharmacologist at the Mayo Clinic in Rochester, Minn.
In one of the most comprehensive comparisons done on an extremely common pain condition, a 1991 study randomly assigned about 150 patients with osteoarthritis of the knee to get 1,200 milligrams of ibuprofen, 2,400 mg of ibuprofen or 4,000 mg of acetaminophen a day. A month later, all three groups reported the same amount of improvement — a reduction of up to 15% in their reported levels of overall pain. The study did not include a placebo.
The higher dose of ibuprofen used in that study is recommended by prescription only. But half as much worked just as well on most measures of pain and range of motion, Nicholson notes — and that kind of result pops up in many studies.
It contradicts what many people do: take larger doses when the pain is particularly bad.
"There's actually a pharmaceutical ceiling effect," Nicholson says. "For the average person, you get a certain effect at a certain level. You could take a ton more medicine, but it's not going to work more for you. It's just going to cause more side effects. That's where people get in trouble."
Uses beyond pain
People most commonly turn to over-the-counter painkillers for headaches and sore muscles. But at low levels, according to growing research, these medicines may also help fight far more serious diseases. Aspirin is the most well-known example. For more than 30 years, doctors have been prescribing a small daily dose to patients at high risk of heart disease.
Unlike the other nonsteroidal anti-inflammatory drugs (NSAIDs), aspirin inhibits enzymes that make platelets in the blood clump and stick together. That, in turn, reduces the risk of clotting. According to the U.S. Health and Human Service's U.S. Preventive Services Task Force, a daily dose of baby aspirin (81 mg) or a dose of regular aspirin (325 mg) taken every other day can reduce the risk of heart attack in men ages 45 to 79 by 32%. For women ages 55 to 79, the risk of stroke from blood clotting drops by 17%.
Those benefits, which are greatest for people who already have existing risk factors for heart disease, must be weighed against the risks of frequent aspirin use, and it's important to talk with your doctor before starting any regular aspirin regimen.
Daily aspirin use may also help prevent cancer, according to a study published in December in the journal the Lancet. Based on eight British trials that included more than 25,000 patients, the authors reported that the chances of dying of certain types of cancer were more than 20% lower in people who took about 75 mg of aspirin daily for a few years. That's a slightly lower dose than in one American baby aspirin.
After 20 years, risks were between 30% and 60% lower for a range of cancers, including lung, colorectal and esophageal. Scientists are still trying to figure out why this may be.
Ibuprofen too might have disease-fighting powers, especially in the brain. Several studies have linked its use with a lowered risk of Parkinson's disease. One analysis of close to 150,000 people, reported in 2005, found that those who had taken the NSAID daily were nearly 40% less likely to develop Parkinson's compared with people who didn't take the drug. People who took ibuprofen less than two times a week lowered their risk by 27%.
And a 2008 study of nearly 50,000 U.S. veterans with Alzheimer's and nearly 200,000 without the disease found that regular use of ibuprofen over a period of five years was linked to a more than 40% reduced risk of developing Alzheimer's. The benefit was larger for ibuprofen than for any other type of NSAID, and the longer the veterans took the drug, the more protection they got.
It's not yet clear why NSAIDs in general and ibuprofen in particular might help protect the brain, says lead researcher Steven Vlad, a rheumatologist and epidemiologist at the Boston University School of Medicine. But plaques in the brain associated with Alzheimer's are known to generate low levels of inflammation. And researchers think that ibuprofen may target an enzyme involved in producing these plaques.
Still, Vlad adds, though the numbers in all of these studies might seem striking, there are major caveats. It's not clear exactly how many people could be expected to benefit from the drug. And it's not yet possible to know whether the drugs are responsible for the drop in disease risk or if there's something else about the people who choose to take the drugs that might protect them.
For now, Vlad says, the risks and unknowns of long-term use of NSAIDs are too great for doctors to recommend them as prophylactics against cancer or dementia.
If you find yourself frequently and repeatedly taking any kind of painkiller for any reason, it may be time to reexamine your behavior and talk with your doctor about your concerns, adds Peter Goadsby, director of the headache program at UC San Francisco.
"It's just worthwhile for people to ask themselves, 'Do I really keep these everywhere? Have medications become part of my lifestyle?'" he says. "If so, then it's a lifestyle you might want to change."