A group of Australian researchers have said paracetamol is ineffective at treating back pain and osteoarthritis, BBC reports.

In their review of 13 clinical trials  involving more than 5,000 patients which was published in the British Medical Journal, they said the drug did not reduce disability or improve quality of life, instead it increased the odds of liver problems.

Furthermore, in osteoarthritis in the hip or knee, they found a small improvement with paracetamol. Yet the impact was so small it was "not clinically important".

According to Dr Christian Mallen, from Keele University in the UK, he said options other than drugs should be the "cornerstone" of managing the conditions.

Meanwhile, in the UK, the safety of over-the-counter drugs is being reviewed by the medicines safety regulator.

Throwing more light on pink killers, Jane Tadman from Arthritis Research UK said:

"We've known for some time that paracetamol may not work for everyone with severe pain from their arthritis, but some people find it helps them and allows them to sleep and to exercise without discomfort."

Prof Roger Knaggs, from the Royal Pharmaceutical Society also said there were other medicines, such as nonsteroidal anti-inflammatory drugs and opioids, which may provide better pain relief but they are associated with a range of other side-effects.