Volume 2

Cannabis : the scientific and medical evidence / Select Committee on Science and Technology.

  • Great Britain. Parliament. House of Lords. Science and Technology Committee.
Date:
1998
Catalogue details

Licence: Open Government Licence

Credit: Cannabis : the scientific and medical evidence / Select Committee on Science and Technology. Source: Wellcome Collection.

    42/316 (page 34)
    28 April 1998] Lord Walton of Detchant contd.] (Professor Wall) You ask two interesting questions there. The specific model that I mentioned of nerve damage is the nearest approach in animal models to a state of causalgia. It has all of the characteristics of on-going pain sensitive to the sympathetic system itself. Now you ask what might be the action of these. You understand I am not going to be able to tell you the answer to that, but I can say that work is going on and one knows what work should be done. You have read that what has appeared is that there are two quite separate groups of receptors for these cannabis drugs. One group is present in the brain and also on the terminals of peripheral nerve fibres, that is the receptor type one; and receptor type two is hardly present at all in the central nervous system but markedly present out in the periphery. That brings up the first question of whether we are talking here about an action on the central nervous system, including perhaps the autonomic system, or are we talking about action in the peripheral tissues? Of course, it could be both. When you think of the strong stories that we have been hearing about therapeutic action, glaucoma, asthma, nausea, bladder, all of those actions could be actually in the periphery, on blood vessels, on the sympathetic system and so on and this is one of the major questions at the moment. In the case of this work of Andrew Rice at St Mary’s, they actually think they are looking at a peripheral action of the development of inflammation. This leads on to questions you will be asking me about whether one could separate central actions from these therapeutic actions. It is an exciting period and one does not know the precise answer to your question, which is the most important question for the scientists, but there are ways of finding out. Lord Winston 102. The analgesic effects we are describing, do these occur before the more psychoactive effects, the feeling of being stoned, for example? (Professor Wall) In some ways Clare Hodges is precisely the person to answer that. She does not like getting stoned, as she has told us, it disturbs her life. (Miss Hodges) I feel that when you are ill your overwhelming motivation is to get better and to be as well as you can and I am as well as I can by taking a small amount. I have experienced this stoned or high feeling or whatever and I do not really like it, to be honest. I do it on my own. What fun is it? I have got two young kids. I want to function. I want to get up, make the tea, converse with them and be alive rather than concentrating on whether or not I have got to go to the toilet. I am not interested in getting stoned. It is not the object of the exercise at all. Chairman 103. Can we perhaps come back to the question of natural cannabis and the problem with that as opposed to the cannabinoids. I understand the Alliance wants medical preparations of natural cannabis to be made available on prescription. What sort of preparations would they be and who would make them available? How do you see exempting [Continued cannabis from the usual procedures for licensing medicines? Would the benefits of self-treatment be lost, particularly since doctors are unlikely to be willing to prescribe cigarettes? (Professor Wall) That is a large number of questions. Shall we start first with the question since there are pure synthetic single molecules available, why not concentrate on those, which is in fact one of the conclusions of the BMA report. There are a series of such molecules available. Cannabis itself is a mixture of a number of active compounds. Have the active components already been _ extracted, synthesised and made available in pure form? You have a paper in front of you and Dr Notcutt has tested a number of patients by giving them the available pure cannabinoids, patients who were reporting an effect of cannabis. Not one of them said that Nabilone was as effective as cannabis. That really is anecdotal. You may say, “Well, they would say that, wouldn’t they?”, but all the same, I think it needs to be taken into account. Certainly I am not saying cannabis is superior to any of these alternatives. That is precisely the sort of question that needs testing because it is quite possible that cannabis contains a mixture of compounds which act synergistically. We know that there are two major routes of action of cannabis. It could be that they are working together. Again going back to the narcotics example, opium contains a mixture of effective compounds, not just morphine and it is still widely used as Omnipon which is a mixture of the compounds from opium. All that we are saying in pushing for cannabis is it would be premature at this stage of our knowledge to say, “Right, we can get rid of cannabis and concentrate on one of the purified cannabinoids.” Your next questions was on the method of administration. I think it is completely unrealistic to consider a serious investigation of smoking anything, including cannabis. So that is out for a number of extremely obvious reasons. Many patients that we could be talking about simply are not used to smoking. We cannot teach them how to smoke let alone all the obvious things against smoking. There are, therefore, a number of other ways of administration under investigation and, after all, until 1972 tincture of cannabis was available. That is what Queen Victoria used for her period pains. Oral cannabis is available, it has the disadvantage of slow absorption, slow onset, but serum levels can be measured. There are other methods being investigated such as an inhaled spray. Dr Pertwee will tell you about suppositories and patches are under investigation. So, yes, as with all drugs the route of administration has to be looked at. Lord Porter of Luddenham 104. Clare, you have given us a very vivid and interesting description of your own experiences of this. Have you taken cannabis any other way than smoking it? (Miss Hodges) Yes, I did. I have varied it. It depends very much. Fora while I grew it at home and that was a perfect situation because I knew the strength and I could measure it much more easily and