|The CAMS trial is an RCT of the effects of cannabis on the symptoms of Multiple Sclerosis (MS).
Cannabis has been used medicinally for over 2000 years including for the relief of pain, cramps, nausea, and fits. Famously, Queen Victoria was prescribed cannabis for menstrual cramps by her personal physician, Sir Russell Reynolds. In 1971, the drug was reclassified as a Schedule One drug, meaning that it is regarded as having no medical value and a high potential for abuse. More recently, many sufferers from multiple sclerosis have reported that using cannabis (illegally) has helped their symptoms and in 1998 the House of Lords called for further research.
The CAMS trial investigates whether cannabis, as either whole plant extract or one of its active components, can help the muscle stiffness and spasms. The trial closed in October 2002 having met its recruitment target with 667 patients.
All trial treatments are given orally (i.e. no patients will be asked to smoke cannabis): Treatment A (given to 1/3 patients) is cannabis oil and Treatment B (given to 1/3 patients) is tetrahydrocannabinol, which is believed to be the active ingredient in cannabis; the remaining patients receive a placebo.
This is a double-blind, placebo-controlled trial. Because of difficulties in making the active treatments look alike, there are two treatment arms and two placebo arms (see figure 5). Patients may know that they are on an A arm, but not whether they are on treatment A or placebo A (and similarly with B).
The primary outcome measure is muscle spasm (also known as spasticity) using a clinical assessment scale known as the Ashworth scale. The secondary outcome measures are mobility, quality of life, disability and side-effects. Results should be available in Summer 2003.
The trial is sponsored by the MRC. It is led from Plymouth by Dr John Zajicek and coordinated by Dr Jane Vickery. Support is being provided by the MRC Clinical Trials Unit. Over 20 UK sites are taking part.