RESEARCH - Assessment of the efficacy, tolerability and safety of a cannabis-based medicine for RA pain

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Rheumatology Advance Access originally published online on November 9, 2005

Preliminary assessment of the efficacy, tolerability and safety of a

cannabis-based medicine (Sativex) in the treatment of pain caused by

rheumatoid arthritis

D. R. Blake, P. Robson1, M. Ho2, R. W. Jubb3 and C. S. McCabe

Royal National Hospital for Rheumatic Diseases, Bath, 1 Cannabinoid Research

Institute, Oxford Science Park, Oxford, 2 Department of Rheumatology,

Northampton General Hospital, Northampton and 3 Department of Rheumatology,

Selly Oak Hospital, Birmingham, UK.

Objectives. To assess the efficacy of a cannabis-based medicine (CBM) in the

treatment of pain due to rheumatoid arthritis (RA).

Methods. We compared a CBM (Sativex) with placebo in a randomized,

double-blind, parallel group study in 58 patients over 5 weeks of treatment.

The CBM was administered by oromucosal spray in the evening and assessments

were made the following morning. Efficacy outcomes assessed were pain on

movement, pain at rest, morning stiffness and sleep quality measured by a

numerical rating scale, the Short-Form McGill Pain Questionnaire (SF-MPQ)

and the DAS28 measure of disease activity.

Results. Seventy-five patients were screened and 58 met the eligibility

criteria. Thirty-one were randomized to the CBM and 27 to placebo. Mean

(S.D.) daily dose achieved in the final treatment week was 5.4 (0.84)

actuations for the CBM and 5.3 (1.18) for placebo. In comparison with

placebo, the CBM produced statistically significant improvements in pain on

movement, pain at rest, quality of sleep, DAS28 and the SF-MPQ pain at

present component. There was no effect on morning stiffness but baseline

scores were low. The large majority of adverse effects were mild or

moderate, and there were no adverse effect-related withdrawals or serious

adverse effects in the active treatment group.

Conclusions. In the first ever controlled trial of a CBM in RA, a

significant analgesic effect was observed and disease activity was

significantly suppressed following Sativex treatment. Whilst the differences

are small and variable across the population, they represent benefits of

clinical relevance and show the need for more detailed investigation in this

indication.

http://rheumatology.oxfordjournals.org/cgi/content/abstract/45/1/50

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