July 25, 2014
News Review From Harvard Medical School -- Tylenol May Not Relieve New Back Pain
Though it's used widely for many kinds of pain, acetaminophen (Tylenol and generics) may not help new back pain, a study suggests. The study included 1,650 adults with new pain in the lower back. They were randomly divided into 3 groups. One group got usual doses of paracetamol for up to 4 weeks. That's the name for acetaminophen in Australia, where the study was done. A second group received identical placebo (fake) pills. A third group got some of each. On average, people in all groups felt better in just over 2 weeks. There were no differences among the groups in pain, sleep problems, disability or quality of life. The journal Lancet published the study. HealthDay News wrote about it July 23.
By Mary Pickett, M.D.
Harvard Medical School
What Is the Doctor's Reaction?
When it comes to drug benefit, there is nothing quite like a randomized, placebo-controlled study for showing the facts. This week, a high-quality study has surprised doctors and patients alike. It found that acetaminophen (Tylenol and generics) is no more helpful than placebo pills for low back pain.
The study had 1,643 patients and was based in Australia. The drug tested was paracetamol. That's the name in most countries for the medicine we call acetaminophen. People in the study had new back pain, not long-term (chronic) back pain. They were randomly divided into groups. Some patients got usual doses of acetaminophen and some got placebo pills. A third group had some of each.
All of the groups had the same rate of recovery. Acetaminophen and placebo had the same amount of effect on:
- Quality of life
Hold it. I have trusted in acetaminophen. I recommend it to my patients multiple times per day, for many different pain problems. Is this study telling us that it does not help pain?
This study has convincing results. But its message is limited to back pain. For example, acetaminophen has seemed helpful in studies for dental pain, cancer pain and pain after surgery. So was this study flawed? Were the other studies flawed? Is this a huge "placebo effect," feeling better because you believe you are taking a real medicine? Or is back pain special?
Maybe, in some ways, back pain is special. New back pain often involves two pain problems that we know acetaminophen can't help very well. The first is inflammation. The second is nerve pain.
Inflammation happens when there is a ruptured disc in the back. It can last a couple of weeks. This is what happened in the study. For all groups, back pain went away within about 17 days.
About 20% of patients had obvious nerve pain. They had burning or pain that extended down the leg, lower than the knee.
I respect this study's findings. And I have to say, I feel let down by my trusted Tylenol. I would have expected to see at least a small benefit.
This study reminds me that we truly don't understand the way acetaminophen works. It has very weak similarities to ibuprofen and other non-steroidal anti-inflammatory drugs (NSAIDs). But experts can only guess at the way Tylenol works.
Because of this study, acetaminophen is now much lower on my list of recommended treatments for back pain. It is well worth a try, though, if you are not getting relief from NSAIDs.
Remember that this study was only for people with new back pain. Long-term back pain often involves deconditioned muscles. In this case, there is no inflammation or nerve pain. Perhaps acetaminophen still can offer a benefit in these cases.
What Changes Can I Make Now?
This study reminds us of an important fact about new back pain. It almost always goes away within a few weeks. Even though acetaminophen didn't help pain any more than placebo, three out of four patients in each study group were satisfied with their treatment. So with or without treatment, you can expect most cases of new low back pain to go away.
To help low back pain, I recommend simple measures:
- Stay active. Movement is medicine. Keeping your back in use will prevent loss of muscle tone, which can cause its own back pain problem.
- Use NSAID medicines, such as ibuprofen (Motrin, Advil and generics) or naproxen (Naprosyn, Aleve and generics). If you can't take an NSAID or if it doesn't help, I don't see any harm in trying usual doses of acetaminophen. If it does not seem to help, just stop taking it.
- Check your workstation. Good posture at work can be a major help for back pain.
- Check your shoes. They should have good cushioning. Avoid high heels, which can strain the curvature of your back.
- Consider your mattress. It may be time to get a mattress with better back support.
- Try applying heat. You can buy warming adhesive patches (such as the brand "ThermaCare") at pharmacies. These patches release heat for 8 hours or more. They can be very helpful.
- Build a team of caregivers. Involve your doctor in your pain management, as well as a physical therapist and potentially other specialists.
What Can I Expect Looking to the Future?
If we believe the findings in the study, acetaminophen should be used less often as a first treatment for low back pain. The study authors are cautious. They say we should repeat a similar study, to see if we get similar results. Meanwhile, they advise us not to discard acetaminophen as a treatment for back pain. That seems like a prudent idea.
In prior studies, acetaminophen and NSAIDs have seemed to offer similar benefit. I guess this means that neither type of drug can really knock the socks off back pain. NSAIDs deserve a similar placebo-controlled trial. That will help us update our expectations about how well those medicines work for back pain, too.