Paracetamol appears to lack efficacy for lower back pain and osteoarthritis

by Bruce Sylvester: Paracetamol is not effective for treating neck and lower back pain, and it provides only slight relief for osteoarthritis, researchers reported on March 31, 2015 the BMJ/British Medical Journal.

Worldwide, paracetamol is a first line drug treatment for both conditions.

Gustavo Machado Ph.D, (cand.) at The George Institute for Global Health at the University of Sydney in Australia and his team conducted a review and meta-analysis of relevant research, to determine the efficacy and safety of paracetamol for lower back pain and osteoarthritis of the hip or knee.

They identified 13 randomized studies comparing the clinical effects of paracetamol with those of a placebo. Ten of the studies enrolled 3,541 subjects and evaluated paracetamol treatment for pain associated with osteoarthritis of the hip or knee. Three of the studies enrolled 1,825 subjects and evaluated  paracetamol treatment for lower back pain.

The investigators pooled data and analyzed it for reduction of pain intensity, improvement of disability and quality of life, and safety and patient adherence.

For lower back pain and compared with placebo, paracetamol showed no clinical effect and failed to reduce disability or improve quality of life.

For osteoarthritis and compared with placebo, paracetamol subjects showed a statistically insignificant reduction of pain and disability.

Notably, paracetamol treatment of osteoarthritis appeared to increase abnormal results on liver function tests when compared with a placebo. However, the clinical relevance of this finding is not clear, noted the authors.

There were no differences in drop-out rates between paracetamol and placebo subjects in the trials. And adherence to treatment was similar among subjects in both treatment populations.

The authors noted that the trials in this meta-analysis evaluated short-term paracetamol and placebo use, and that more research is needed to determine any long-term clinical effects.

They concluded that, “these results support the reconsideration of recommendations to use paracetamol for patients with low back pain and osteoarthritis of the hip or knee in clinical practice guidelines.”

In an editorial  published in the same issue of the BMJ, Professors Christian Mallen and Elaine Hay from Keele University in the UK said that this new research “re-opens the debate” about efficacy and safety of paracetamol.

They noted that if paracetamol is removed from existing guidelines, the use other prescribed drugs, such as opioids, could increase. They called for the use of effective non-drug options, likes exercise, which have shown efficacy for spinal pain and osteoarthritis.