Acetaminophen is recommended as a first-line treatment for acute lower back pain according to medical guidelines. However, this recommendation has not been supported by research. A new study published in The Lancet found that acetaminophen is no better than a placebo in treating back pain.
Researchers from the George Institute for Global Health in Sydney conducted a randomized, placebo-controlled study of about 1600 people with acute, low back pain. Participants were randomized to one of three groups, each given one regular box and one as needed box. The first group received two boxes containing acetaminophen, the second group received a regular box containing acetaminophen and an as needed box containing placebos and the third group was given two boxes containing placebos. Participants were instructed to take six tablets a day from the regular box and up to two tablets a day from the as needed box. Participants were followed for three months, after which researchers found no differences among the three groups in terms of recovery time, pain, disability, function, symptom change, sleep or quality of life. And three quarters of the participants reported being satisfied with their treatment.
The study did have several limitations, the major one being that there was no group included that received no treatment, making it impossible to rule out a placebo effect. It's possible that patients in all three groups got better faster than they would have with no treatment a phenomenon known as the placebo effect, said Dr. Michael Mizhiritsky, a physical rehabilitation specialist at Lenox Hill Hospital in New York who was not involved in the study.Additionally, although the group assigned to take acetaminophen regularly and as needed was told to take about 4000 mg each day, participants reported on average taking under 3000 mg a day. It is possible that the recommended dose would have had an effect.
Dr. Bart Koes, a professor of general practice at Erasmus University Medical Center in Rotterdam, the Netherlands and author of an accompanying editorial says, The fact that it s [acetaminophen] no more effective than placebo does not mean that it doesn't work for a given patient. And study authors add that future research should focus on developing new, more effective treatments for acute lower back pain.