Paracetamol (acetaminophen) proved to be no better than a placebo in calming lower back pain or improving levels of function or the effect it has on sleep.
The findings, published in The Lancet, calls into question the effectiveness of the widely-used drug.
National Australian guidelines cite paracetamol as the top choice for curing lower back pain, but taking the medication could be pointless. In past studies the treatment has never been solidly proven to improve lower back pain.
The The Paracetamol for Low-Back Pain Study (PACE) assigned 1,652 individuals to either take paracetamol every day for four weeks, take it as needed for four weeks, or receive a placebo. The participants were then followed up for three months.
No difference was observed between the three groups; the median recovery time was 17 days in both paracetamol groups and 16 days in the placebo group. The drug also proved to have no effect on "short-term pain levels, disability, function, sleep quality, or quality of life." The number of participants who reported adverse effects was also similar between all three groups.
"Simple analgesics such as paracetamol might not be of primary importance in the management of acute lower back pain," said lead author Dr Christopher Williams from the George Institute for Global Health at the University of Sydney in Australia. "The results suggest we need to reconsider the universal recommendation to provide paracetamol as a first-line treatment for low-back pain, although understanding why paracetamol works for other pain states but not low-back pain would help direct future treatments."
"In view of the quick timeframe in which participants in our trial improved compared with other cohorts, it would be interesting to see whether advice and reassurance (as provided in our trial) might be a more effective than pharmacological strategies for acute episodes of low-back pain," the research concluded.
