by Emma Rayner, University of Nottingham

Medication normally used to treat depression and anxiety could give new hope to chronic pain suffers.

Researchers at the Arthritis Research UK Pain Centre, based at The University of Nottingham and Nottingham City Hospital, are inviting people to take part in a clinical trial to determine whether a drug called Duloxetine can be used to treat chronic knee pain, known as osteoarthritis.

Patients who participate in the study are put into one of two groups. One group is given Duloxetine, while the other group receives a dummy treatment, known as a placebo.

Diane Reckziegel from The University of Nottingham and Chief Investigator for the study, said: "As we get older or sustain injuries our joints, especially the knees, begin to show signs of deterioration. This causes pain that may become chronic over time.

"The most effective treatments for knee osteoarthritis are typically quite invasive, involving steroid injections into the joint or surgery to remove the diseased joint, which is then replaced with an artificial joint."

Before taking the medication patients undergo MRI scans of their brain. After the six week course of medication they then return for an MRI scan where the effects of the medication will be assessed through questionnaires, imaging and sensory tests.

Diane added: "Duloxetine has already been shown to be effective in relieving different types of chronic pain, however what we don't know is how this drug works to reduce pain, and to whom it may be more useful.

"By comparing the brains of patients with osteoarthritis before and after the treatment we hope to achieve a better understanding of the mechanisms of pain relief. This will help us select patients who might benefit more from Duloxetine treatment, hopefully avoiding the need for invasive procedures."

The trial, which began at the start of the year, is aiming to recruit 81 patients before May 2016. So far 44 patients have been recruited.

One patient who is taking part in the trial is 64-year-old Catherine Parnaby from Keyworth. The retired school supervisor was diagnosed with osteoarthritis eight years ago. She said: "My knees get very painful, even painkillers don't work at times. I joined the trial after receiving a letter from my GP and wanted to see if a different approach would help my pain."

During the trial Catherine was unaware whether she was taking Duloxetine or the placebo, however after the trial she was told that she was on the Duloxetine drug. Catherine said: "During the trial my pain went away. I was able to swim further and walk quicker and the tablets I took were much better than the painkillers I had been taking. I really hope this trial makes a difference and Duloxetine becomes a recognized treatment for osteoarthritis because it helped me.

"If anyone else gets the chance to get involved in this trial then I would tell them to go ahead and try it. It was great for me."

The Arthritis Research UK Pain Centre is a partnership between NUH, The University of Nottingham and Arthritis Research UK. It is hosted at Nottingham City Hospital and was established over five years ago to investigate the mechanisms that lead to the chronic pain experienced by sufferers of arthritis and improve the treatment of arthritic pain.

Provided by University of Nottingham