By Erica Mather 27/05/2016

Swiss researchers reveal that the vaporisation of cannabis oil, termed ‘cannavaping’ is a less hazardous way to administer medicinal cannabis compared to smoking, as published this week in Scientific Reports.

Vincent Varlet and colleagues used butane gas to extract the psychoactive constituents (cannabinoids) from cannabis, producing butane hashish oil concentrate, which was then atomised using e-cigarettes. By analysing the gases generated, the authors found significantly lower levels of the toxic contaminants released during the combustion of regular cannabis cigarettes – including volatile organic compounds (VOCs) and carbonyls.

The authors suggest cannavaping as an alternative to smoking marijuana for therapeutic purposes as a “gentle method” of delivering the mind altering substance tetrahydrocannabinol (THC).  They reject the possibility that recreational cannavaping will become popular; the poor solubility of the oil in commercial liquid refills makes it difficult to attain concentrations that generate the desirable psychoactive ‘high’.

This research follows continued debate around the legalisation of selling regulated cannabis products in New Zealand which featured prominently at the annual international conference on drug policy that was hosted in Auckland earlier this month by Massey University.

Cannavaping a possibility in NZ regulatory model

Leading drug researcher Dr Chris Wilkins from Massey University’s SHORE and Whariki Research Centre delivered a keynote speech at this conference, describing a potential regulatory model for recreational cannabis and legal highs in New Zealand. He proposes a not-for-profit club model for cannabis to be established where Cannabis Incorporated Societies could legally sell approved cannabis products to registered adult members, whilst promoting both an awareness of the health risks of cannabis use and local drug treatment services.

“Cannabis Incorporated Societies are a middle ground option. The sale and taxation of approved cannabis products by the government will provide tax revenue to support drug treatment services and to fund enforcement against remaining black market cannabis sales.”

Dr Wilkins also addresses the health risks from smoking cannabis and suggests less harmful alternatives, touching on the possibility of cannavaping:

“The Incorporated Societies will only be able to sell the government approved healthier forms of cannabis – meaning non-smoking products, so edibles, liquids that can be vaporised, things like that.”

A study, published last month in the New Zealand Medical Journal found that almost one in 20 New Zealanders report using cannabis for medicinal purposes. A national survey collected information from 13,000 people over the age of 15. Medicinal cannabis users tended to be young, less educated males who relied on the effects of cannabis to allievate conditions that are typically difficult to manage – chronic pain, anxiety and depression.

Medical marijuana dispensary. CC Wikipedia

The authors considered the involvement of medical practitioners, suggesting a prescription system that could provide better opportunity for professionals to advise cannabis users on appropriate quantities and methods of use, thereby minimising potential harms.  The authors note:

“This is contingent, however, on doctors having the knowledge to give to such users.”

Academics respond

In the wake of this study, three academics were interviewed in an online briefing held by the Science Media Centre to provide information about the current state of research on medical cannabis and New Zealand’s prescribing framework.

Associate Professor Michelle Glass, Head of the University of Auckland’s Pharmacology Department, stressed the need to better define medicinal cannabis, especially as the term is used more broadly in media coverage than is appropriate.

“Medicinal cannabis can refer to a wide range of products, with different active compounds. Not all products are of high or consistent quality. If cannabis products are going to be offered as medical treatments, quality and consistency needs to be ensured.”

High quality cannabis products are known to give modest pain relief for cancer patients as discussed during the online briefing by Dr John Ashton from the Pharmacology and Toxicology Department at the University of Otago.  According to Dr Ashton, emerging evidence suggests that medicinal cannabis products could provide an alternative pain relief option for people who are resistant to the effects of opiates.

Andrew Zielinski from the New Zealand Drug Foundation contributed to the online briefing by commenting on the indicators of policy changes around medicinal cannabis. As Associate Health Minister Peter Dunne is reviewing the guidelines for medicinal cannabis assessments and approval, a greater range of products could be accessed more easily.  Mr Dunn states:

“It is my hope that by releasing this feedback it will go some way to balancing out the irresponsible and ill-informed messages being passed off as fact, and provide a degree of reassurance to those who are genuinely looking for respite to significant health issues.”

This issue is not receding

Last week Labour confirmed their wish to legalise medicinal cannabis. Labour leader Andrew Little said anyone suffering from chronic pain or a terminal condition should be able to access medicinal cannabis from their medical practitioner, removing the approval that is currently required from the Health Minister.


Featured image: CC flickr,

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