‘’False hope’’ driving claims medicinal cannabis is ‘’magic pill’’ for chronic pain relief

Prescribing medicinal cannabis for patients with chronic non-cancer pain is not going to revolutionise their treatment and should not be supported until there is substantial proof of its effectiveness, according to a leading pain specialist.

Professor Milton Cohen is presenting Medicinal cannabis for chronic non-cancer pain: promise or pothole? at the Australian and New Zealand College of Anaesthetists (ANZCA) annual scientific meeting in Brisbane on Saturday May 13.
 
“There is no reason to be enthusiastic about cannabinoids in the treatment of non-cancer related chronic pain,’’ Professor Cohen said.
 
‘‘On the basis of what we know about cannabis as a treatment it’s not going to revolutionise the field of chronic pain management.’’
 
Professor Cohen is a specialist pain medicine physician in Sydney and Director of Professional Affairs for ANZCA’s Faculty of Pain Medicine. The Faculty does not support the use of cannabinoids in chronic non-cancer pain ‘’until such time as a clear therapeutic role for them is identified in the scientific literature.’’
 
Professor Cohen said he was concerned that ‘’anecdote and clamour’’ and ‘’community enthusiasm’’ had preceded science on the issue of prescribing medicinal cannabis for patients who suffered chronic non-cancer pain. As a result, a culture of ‘’false hope’’ based on the elusive idea of a ‘’magic pill’’ was driving community misinformation about medicinal cannabis as a treatment for such patients.
 
The Federal government last year legalised a pathway for access of patients to Australian-grown and manufactured medicinal cannabis, subject to state and territory government regulations. In New Zealand, the use of cannabis-based products for medicinal purposes is available only on prescription authorised by the Ministry of Health.
 
‘’It’s a classic example of the cart being put before the horse with a political imperative to facilitate access to an unproven medicine,’’ Professor Cohen said. International studies that have assessed the effectiveness of medicinal cannabis for non-cancer chronic pain have revealed very ‘’modest’’ effects, he said.
 
‘’The international data on which one could make an informed decision about the effect of medicinal cannabis on chronic non-cancer pain is in fact very poor. The conclusions have been oversold,’’ he said.
 
Professor Cohen said the management of chronic non-cancer pain is complex as it required consideration of a range of factors including the medical, physical, psychological and social.
 
‘’We know that chronic pain is a much more complex phenomenon which requires a holistic approach to management that is tailored to the individual's circumstances. To rely only on medicines is just not going to work.
 
‘’If doctors are to prescribe substances—that is if they are to be available on doctors’ prescriptions—they should be proven substances,’’ Professor Cohen explained.
 
Professor Cohen cited an ongoing study of 1500 people who had been prescribed opioids for chronic non-cancer pain, undertaken by the National Drug and Alcohol Research Centre at the University of New South Wales. Almost half of those surveyed said they had used cannabis for recreational purposes, one in six admitted to using cannabis in search of pain relief and one quarter said they would use cannabis in search of pain relief if they could.
 
‘’We know that cannabis is freely available but we also know that drugs are not the mainstay of managing chronic pain,’’ Professor Cohen said.
 
Professor Cohen said that, given the legislative changes introduced by the Federal government and some states and territories, the introduction of individualised trials of medicinal cannabis for patients with chronic non-cancer pain to monitor and evaluate its effectiveness and adverse effects might be considered. This would require the development of a patient register, similar to an approach introduced in Israel, to ensure that the trial was properly monitored and managed.
 
‘’Given the reality of the situation – these substances are going to be produced in Australia and will be marketed -- so there now is an opportunity for individual, personalised clinical studies to ascertain if there is a benefit from this treatment,’’ Professor Cohen said.

Saturday May 13, 2017 

 
Copyright © Australian and New Zealand College of Anaesthetists.