Rapid Responses to:
|
|
Rapid Responses: Rapid Responses published:
-
![[Read Rapid Response]](/icons/misc/sectionDOWN.gif)
Psychosocial factors in research on cannabinoids
- Brenda Coldwell (14 July 2001)
-
Cannabis exacerbating pain
- Sian Koppel (31 July 2001)
-
Endpoints need to be clinically relevant
- Jean Potter (7 August 2001)
|
|
|||
|
Brenda Coldwell, Consultant in Clinical Psychology, Addictions Specialist Duchess of Kent's Psychiatric Hospital
Send response to journal:
|
I read with interest the research papers by Tramer et al, (1), Campbell et al, (2) and the editorial regarding the above research. That cannabinoids are less effective and have more adverse side effects than more modern drugs is unsurprising. It is also possible to predict that research on the use of cannabis to alleviate pain and tremors in multiple sclerosis will produce similar results, however, any research needs to take into account that people always amount to more than their bio- chemical make up. When considering the use of an illicit drug to self medicate we must place the behaviour and outcome into context. Multiple Sclerosis, a chronic and incurable condition, often leaves the sufferer with feelings of helplessness and hopelessness. Anger at the medical and other caring professionals at their failure in "curing" the disease, distress at the inevitable deterioration of the body and anxiety about the loss of control over bodily functions and the future often leads people to seek alternative "therapies". In procuring a "treatment" denied by the government, the law and the medical profession, the person is able to perceive themselves as taking control. Whilst most people are law abiding the very fact of going beyond the law in order to secure effective "help" is likely to be empowering. This "law breaking" behaviour is tacitly supported by the wider law abiding public in that sympathy with the sufferers plight can make the law appear wrong. In addition to the beneficial side effects identified in some people Tramer et al (1), I would suggest that the very act of seeking and "using" cannabis is likely to increase the persons self esteem, decrease feelings of helpless and hopelessness, and "taking control of one's destiny" will, initially, alleviate anxiety and depression. These effects go beyond any chemical property or action of the drug. In the unlikely event that research finds cannabis to be more effective (and have less adverse side effects) than current treatments, the very fact of legalisation for medical use may prove counterproductive as a strategy in that the context, behaviour and personal control issues are inevitably altered. If, in the future, cannabis or cannabis compounds should be prescribed, further evaluation and research taking the above points into account would be essential. Brenda Coldwell, The author is expressing her own views in this response and not those of the Ministry of Defence. 1 Martin R. Tramer, Dawn Carroll, Fiona A Campbell, D John M Reynolds, R Andrew Moore, Henry J McQuay: Cannabinoids for control of chemotherapy induced nausea and vomiting: quantitative systematic review. BMJ 16-21, Vol 323 (July 2001) 2 Fiona Campbell, Martin R Tramer, Dawn Carroll, D John M Reynolds, R Andrew Moore, Henry J McQuay: Are Cannabinoids an effective and safe treatment option in the management of pain? A qualitative systematic review. BMJ 13-16 Vol 323 (July 2001) 3 Eija Kalso: Editorial - Cannabinoids for pain and nausea. BMJ 2-3 Vol l323 (July 2001) |
|||
|
|
|||
|
Sian Koppel, SpR in Forensic Psychiatry Caswell Clinic, South Wales
Send response to journal:
|
It was for personal reasons that I read with interest the article assessing the efficacy of cannabinoids in controlling pain. No reference was made to the phenomenon I observed (when I tried cannabis for the first time, for its analgesic properties) of cannabinoids causing an increase in pain. As one symptom of early onset Parkinson’s Disease, I experienced a chronic pain associated with right-quadriceps muscle spasm. It is not relieved by paracetamol or non-steroidal anti-inflammatory drugs. Temporary relief is achieved through osteopathic massage. On a trip to Jamaica I sought to avail myself of the freely available cannabis (ganja) in the hope of gaining pain relief. The leaves and (predominantly) flower heads of the plant were dried and rolled in cigarette paper without supplementary tobacco. I felt sufficiently “odd” after two inhalations to resist increasing the dose. As a psychiatrist, I was fascinated by the effects and identification of the resultant psychopathology. Without detailing all these effects, of significance was a general heightening of sensory perception: colours were brighter, sounds clearer and louder, and the pain, for the duration of the period I was under the influence of the drug, was greater. It was with some relief that I could exclude cannabis from my therapeutic armoury. In the literate on the therapeutic area of cannabis I have never seen a reference to the phenomenon of heightened pain, either this experience was unique, or more probably, attempts to establish this paradoxical effect are not routinely made. Siân Koppel Specialist Registrar |
|||
|
|
|||
|
Jean Potter, Clinical Research Fellow Dept of Palliative Care and Policy Guy's King's College and St Thomas's School of Medicine
Send response to journal:
|
Tramer et al's assertion that '[cannabinoids] are superior to conventional antiemetics'(1) is flawed. Such a comparison is limited by the inadequacy of the methods of measurement of outcome. In this systematic review the endpoint of primary interest was defined as 'the complete control of nausea or vomiting in the first 24 hours of chemotherapy'. However, nausea and vomiting may occur for a much wider time frame: 'delayed' nausea and vomiting (peaking at 48 - 72 hours post chemotherapy) are well recognised phenomena (2). In a study of 105 patients receiving outpatient chemotherapy post treatment nausea and vomiting were experienced by 73% and 33% of patients respectively (3). No patient indicated that the period during treatment was the worst, rather these symptoms tended to be at their worst some 24 hours or more after chemotherapy infusion. Tramer et al's study does not tell us how patients faired for the time period when most problems related to nausea and vomiting occur. This review also found high rates of side effects caused by cannabinoids including sedation, hallucinations and substantial effects on mood. Under these conditions patients' judgements of their experience can be severely impaired (2). Nausea can only be measured by patients' self- report. Tramer et al found that the numbers needed to be treated with cannabinoids (NNT) for control of nausea is less than the NNT for control of vomiting (NNT 6 and 8 respectively). This could, in part, be explained by patients' inability to accurately remember their experience of nausea and vomiting rather than an actual reduction in the experience in reality. Tramer et al used a validated score to rate the quality of studies (4). This scoring system assesses the adequacy of various aspects of research methodology. An assessment of the choice of outcome measure is also important. In a meta-analysis of 392 studies of the use of antiemetics Morrow et al found that whilst effect size may be relatively independent of the type of outcome measured (for example nausea or vomiting), the mean effect size did vary according to how the outcome was quantified (5). The mean effect size measured for frequency was statiscally different from measures of duration and furthemore measures of severity were statistically different from measures of duration. The nature and quality of outcome measures (and hence study endpoints)can have a substantial effect on the overall meaning and value of a study, and profound effects on the results of systematic reviews or meta-analyses. In order to be fully relevant, outcomes must address the major problems found in the clinical setting. References (1) Tramer MR, Carroll D, Campbell FA, Reynolds DJM, Moore RA, McQuay HJ. Cannabinoids for control of chemotherapy induced nausea and vomiting: quantitative systematic review. British Medical Journal 2001; 323: 16-21 (2) Olver IN. Antiemetic study design: desirable objectives, stratifications and analysis. Britsih Journal of Cancer 1992; 66: S30 - 34 (3) Watson M, McCarron J, Law M. Anticipatory nausea and emesis, and psychological morbidity: assessment and prevalence among outpatients on mild to moderate chemotherapy regimens. British journal of cancer 1992; 66: 862 - 866 (4) Jadad AR, Moore A, Carrol D, Jenkinson C. Assessing the quality of reports of randomsied clnical trials: is blinding necessary? Controlled Clnical Trials 1996; 17: 1-12 (5) Moorow GR. Methodology and assessment in clinical antiemetic research: a meta-analysis of outcome parameters. British journal of Cancer 1992; 66: S38-S41 |
|||