There is no rush to act on the legalisation of cannabis for medical purposes

TESTING: The benefits of medicinal marijuana for a host of conditions requires further study, with experts arguing there is no need to hurry to legalise its use.
TESTING: The benefits of medicinal marijuana for a host of conditions requires further study, with experts arguing there is no need to hurry to legalise its use.

EVERY week there seems to be a new dramatic and exciting story about the ‘benefits’ of medical marijuana, and the ‘need’ to legalise it for medical purposes. Marijuana is sometimes described as a miracle drug. No need for skilled clinical staff, other drugs, palliative care, and devoid of side effects – the first such drug in history. One could be forgiven for thinking it sounds too good to be true. 

There seems to be a sudden rush to make it available, as if the world was going to run out, or the evidence to use it was new and overwhelmingly good. Sadly, none of this is a reality. There is no new evidence. For all of the conditions discussed, apart from one or two uncommon medical conditions, we already have safe and effective therapies available, and funded by the taxpayer.

It is possible research will find some extract from the plant with benefits for some specific medical conditions. But this will take time. ‘Medical use’ should not be equated to smoking the plant recreationally. It contains a huge number and combination of chemicals. Different growing conditions can change the psychoactive components.

Currently available cannabinoid products have little quality control, testing or certification. Contaminants such as heavy metals, fungicides/pesticides and other chemicals are known to be common in herbal medications. Other psychoactive drugs have been mixed with ‘medical’ cannabis. The stability of the product over time, in heat and light, and its potentially toxic degradative products are also uncertain. These issues are of considerable significance for sick medical patients, often elderly or children.

Medical marijuana should refer to specific cannabinoid molecules isolated from the plant, grown in Good Manufacturing Process (GMP) facility, tested in the usual cell culture lines, animal and human studies, and formulated into capsules or aerosols. This development of a ‘therapeutic good’ requires specific growing, testing, and formulating evidence in addition to clinical trials. We are years away from this.

Despite the hype, the patient experience of medical marijuana is not always good. “It was so frightening I lay down all day until the ‘afraidness’ went away “ (patient with heart failure). “It made me cough and I couldn’t get my breath.” ”Panic attacks and being frightened”. Reports of arteritis and fungal lung infections are not uncommon.

There is a particular danger of enthusiastic promotion of any unconventional therapy. It may lead to unrealistic hopes. Worse, it may divert patients from evidence-based therapies that may have less mystique and glamour, but have been shown to work.

The safety and benefit of any drug that is taken by humans when they are sick and using it for treatment needs rigorously controlled study. Several research groups in NSW are undertaking this work, and our Newcastle team is heavily involved in this aspect. The various molecules in cannabis have pharmacological potential. Whilst this research will not report for several years, we do not believe there is any rush to bring medical marijuana into widespread use. 

Finally, one nagging thought. If marijuana provided such a uniquely beneficial drug, why haven’t the major pharmaceutical companies been into it?

The Newcastle Institute will host a public forum on ‘Drug Myths and Realities: Marijuana and Ice’ at Souths Newcastle Leagues Club on Wednesday, August 17, from 6pm.

Jennifer Martin is a general physician and a Professor of Clinical Pharmacology at the University of Newcastle. She is leading a research program studying medical uses of marijuana.