Arthritis 'pain blocker' success

Scientists say they have discovered a new way to potentially block the pain of osteoarthritis without significant side effects.

They explored the suggestion that a protein called TRPV1 plays a major part in the often debilitating and chronic pain associated with the condition, according to findings published in the journal Annals of the Rheumatic Diseases and highlighted by Nature Reviews Rheumatology.

TRPV1 is produced by nerve cells in the human body that are responsive to pain, including those that respond to stimulation of joints.

Dr Sara Kelly, a lecturer in neuroscience at the University of Nottingham and one of the lead researchers, explained that previous research has indicated that drugs able to 'block' TRPV1 have the potential to reduce the level of pain.

However, she said that these types of drugs, which are known as TRPV1 antagonists, have been linked to overheating of the body - hyperthermia - in clinical trials.

'Using a model of human osteoarthritis pain we wanted to investigate if by blocking these receptors locally within the diseased joint, could we reduce the pain caused by osteoarthritis without the side effect of hyperthermia - and the answer is - yes,' she revealed.

Dr Kelly explained: 'By targeting the joint directly, we did not see the side effect of hyperthermia, which is thought to be generated outside of the joint at the level of abdominal organs.'

Older people at risk of osteoarthritis

She pointed out that osteoarthritis is a 'very common' disease that can cause severe and lifelong pain.

Especially given that many osteoarthritis patients are older people, she continued, it would be preferable to have an effective drug treatment rather than having to undergo a major surgical procedure such as a joint replacement.

'The annual cost of joint replacement to the NHS is close to £200 million, which is another reason to look for a more effective solution.'

Currently, patients in severe pain from osteoarthritis are offered pain relieving drugs that reduce inflammation, such as steroid injections and non-steroidal anti-inflammatory drugs.

However, the use of such treatments is often limited because some of these drugs can be associated with major side effects.

The new drug treatment will now go through extensive trials before it can be considered safe for patients.

Copyright Press Association 2014