Acetaminophen may do little for acute back pain

Nancy Ferrari

Managing Director and Executive Editor, Harvard Health Publishing

When back pain strikes, all you want is relief—as quickly as possible. Many folks turn to over-the-counter pain relievers to help take the edge off and keep them moving. Acetaminophen and non-steroidal anti-inflammatory drugs, or NSAIDs (ibuprofen, naproxen, aspirin), are common and reasonable choices.

Australian researchers set out to see just how helpful acetaminophen is for people with back pain that comes on suddenly (so-called acute back pain). They wanted to know if acetaminophen shortened the time from the start of back pain to complete relief—meaning a pain rating of 0 or 1 (on a scale from 0 to 10, with 10 being the worst) for at least 7 days.

What they found was a bit surprising.

For people who used acetaminophen only when their back pain bothered them, it took about 17 days to get complete relief. For those who took the medication three times a day, it also took about 17 days for full relief. And for those who took a placebo—a sugar pill with no medicine at all—the time to recovery was 16 days. In other words, in this group of volunteers the medication made no difference in how fast back pain went away and stayed away. The researchers also found that all three groups had similar experiences in terms of the severity of their pain, disability, and function. Their findings were published online yesterday in The Lancet.

Does this mean that you shouldn’t bother to use acetaminophen for back pain? Not necessarily. It may work well for some people. And, the alternatives may be worse. Some people should steer clear of NSAIDs. They can irritate the digestive tract and increase bleeding risk among people who take drugs that reduce blood clotting. Muscle relaxants tend to be sedating.

But acetaminophen isn’t without risks and side effects. Taking too much acetaminophen can seriously damage the liver, sometimes leading to liver failure or death. Ideally, the average healthy adult shouldn’t take more than 3,000 milligrams a day. Because combination cold, headache, and sleep products contain acetaminophen, you need to pay careful attention.

Back pain is tricky. Acute back pain may follow something you did at work or at play. It can also be caused by a pinched nerve or a degenerative condition such as arthritis. For one-third of people with acute low back pain, discomfort greatly improves in as little as one week.

Here are some tips for trying to get through the worst of your back pain without medication:

  • Use cold compresses or an ice pack, not heat, immediately after an injury. About 48 hours after back pain hits, heat may be more helpful. The warmth soothes and relaxes aching muscles.
  • Try to keep moving. A limited amount of activity is better than lying in bed. In fact, ask your doctor about appropriate exercises to start sooner rather than later. Exercise therapy can help heal acute back pain and help prevent a repeat episode.
  • Chiropractic manipulation, acupuncture, massage, or yoga provide relief for some people with acute back pain. Several studies support using these alternative/complementary therapies.

Most back pain isn’t dangerous, but it is important to know “red flag” situations that require immediate medical attention. “Be sure to see your doctor right away if you have unexplained back pain with fever, weight loss, or neurological symptoms such as numbness, weakness, or incontinence,” says Dr. Robert Shmerling, clinical chief of rheumatology at Beth Israel Deaconess Medical Center and associate professor in medicine at Harvard Medical School.


  1. Bradley

    Informative Post


    It is a popular form or exercise, but can cause great harm when done in the wrong way. Since it is known to cause injury, many people also think that running is one of the causes of how to strengthen lower back.

  3. Mike

    In the recent Harvard Medical School Special Health Report, Back Pain, there was no mention of Spinal Cord Stimulator (SCS)as an alternative. Why no mention of this technology that has been available for 30 yrs?

  4. Sophia

    Apparently taking too much acetaminophen can seriously damage the liver. Do you know the daily dosage for safe use?

    • Bill

      The current daily limit is four grams but an FDA advisory panel has recommended lowering it in the United States. Health Canada is also re-evaluating the evidence

      A toxic dose for adults is generally considered between 7.5 and 10 grams, with the latter equivalent to roughly 30 regular-strength acetaminophen pills. Anyone who takes that much at once is probably attempting suicide — but it is also possible to hit 10 grams a day without realizing it.

  5. How To Strengthen Lower back

    Physicians will attest that the human body was not created to run marathons. Often, many men and women’s knees are terribly injured because they have jogged a great deal in the past. It is a popular form or exercise, but can cause great harm when done in the wrong way. Since it is known to cause injury, many people also think that running is one of the causes of how to strengthen lower back.

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