Bitter pill: Paracetamol deemed effectively useless for back pain

A study has found the common painkiller paracetamol is effectively useless in providing relief for lower back pain and osteoarthritis.

Tapping into a global database of the best evidence, the review published in the British Medical Journal found that paracetamol was ineffective for lower back pain.

Meanwhile, the benefits for osteoarthritis of the hip and knee were considered too small to be worthwhile.

There is also the risk of liver toxicity; patients were nearly four times more likely to have abnormal liver function tests.

Other potential harms include increased risk of cardiovascular disease and in rare cases, death.

Given the strength of the latest findings, researchers say an urgent review of existing guidelines is needed.

"When you balance out the context of the very little benefit and the potential for harms, then there's very little incentive to encourage patients to continue to take this on a regular basis for their osteoarthritis pain,” Professor David Hunter of the University of Sydney told 9NEWS.

"There are better, safer and more effective treatment options than paracetamol, and so we should be revising the guidelines accordingly.”

For more information, visit MyJointPain.org.au.