Scientists also insist the element of the drug which creates the "high" is an essential therapeutic component of the treatment and cannot be removed.

The authors of the study are now calling for a larger trial to back up their findings to help the 600,000 rheumatoid arthritis sufferers in the UK.

The trial was led by David Blake, professor of bone and joint medicine at the Royal National Hospital for Rheumatic Diseases, Bath, and the University of Bath.

Taken via a Mouth Spray

Of the 56 patients taking part, 31 were given a cannabis-based medicine (CBM) -- brand name Sativex -- while 27 received a placebo.

Sativex uses two key components from a cannabis plant, Tetrahydrocannabinol (THC) and cannabidiol (CBD), which are shown to have anti-inflammatory properties.

Patients took the medicine in the evening via a mouth spray and started with one dose, gradually building up to a maximum of six doses. The trial lasted 49 days and patients were seen seven to 10 days after the treatment finished.

The results, published in the medical journal Rheumatology show that the CBM produced "statistically significant" results.

On a scale of 0-10 for pain on movement, with 0 equalling no pain, those taking the CBM reduced their pain from seven to 4.8. Those on the placebo went from 6.7 to 5.3.

Regarding quality of sleep, those on the CBM went from 5.7 to 3.4, while the placebo group moved from 5.8 to 4.6.

On a scale of 0-100 for intensity of pain at present, patients taking CBM reduced from 48 to 33, while those on the placebo stayed the same at 50.

'Results Are Encouraging'

Dr. Ronald Jubb, consultant rheumatologist at University Hospital Birmingham NHS Foundation Trust, said: "The results are encouraging, with improvements in pain on movement, at rest, the quality of sleep and in the overall conditions of the patient's arthritis.

"Whilst the differences are small and variable across the patient group, they represent benefits of clinical relevance and indicate the need for more detailed investigation through larger trials."

(c) The Herald; Glasgow (UK)
(c) 2005 Daily News Central. All rights reserved.