Drugs - therapeutic use of cannabis
August 2001
The BMA believes that the law should be changed to allow the therapeutic use of cannabis based medicines so that certain cannabinoids - cannabis derivatives – can be prescribed to patients with particular medical conditions that are not adequately controlled by existing treatments.
The BMA draws a clear distinction between the beneficial use of certain cannabinoids for medical purposes and the recreational misuse of crude cannabis. The BMA recognises the adverse effects of smoking crude cannabis which contains many toxic ingredients, some of which are potentially harmful to health in varying combinations and quantities. It can also lead to loss of concentration, affecting, for example, the ability to drive and work, and also has other unpredictable side effects.
Although the BMA believes that crude cannabis is not a suitable medicinal product, the BMA recognises that many normally law abiding citizens have resorted in desperation to the illegal use of cannabis to relieve the pain and other distressing symptoms of medical conditions when conventional drugs have failed to work. The BMA argues that people who break the law in this way should be treated with compassion.
Whilst many such case histories sound convincing, they do not by themselves constitute scientific evidence. Because cannabis contains more than 400 chemical compounds (including more than 60 cannabinoids), simply smoking or eating the drug will not tell us which agents are beneficial. The BMA therefore supports ongoing clinical trials to evaluate the potential therapeutic uses of cannabinoids, alone or in combination, and/or in combination with other drugs.
The main issue for the BMA is to find a drug which can be given in measurable doses and where the side effects are limited. Whilst it is recognised that cannabis has an impact on driving, for example, the scale of the effect (severity and duration) are not known. The BMA would prefer to see a single agent with known bioequivalence which does not have a long term effect on spatial awareness, concentration etc.
Successful trials will lead to the development of targeted medicines, as opposed simply to prescribing crude cannabis which will not resolve the uncertainty and lack of evidence on its pharmacological effects. A central registry should be kept of patients prescribed cannabinoids to allow follow up of long term effects.
A summary of ‘Therapeutic uses of cannabis’ .(BMA Board of Science and Education 1997) is available.
For further information, please contact the parliamentary unit:
E--mail: parliamentaryunit@bma.org.uk.