Pubdate: Tue, 16 Aug 2016
Source: Canberra Times (Australia)
Copyright: 2016 Canberra Times
Author: Steve Robson
Note: Professor Steve Robson is the president of the Australian 
Medical Association (ACT, Limited).


Australians are the world's heaviest users of marijuana, sharing that 
honour with the citizens of New Zealand and the United States. It's a 
kind of a pot-equivalent of the ANZUS treaty.

We seem to have a lot of experience with marijuana, so it surprises 
me that Australia has lagged behind similar countries with socalled 
"medical marijuana".

Catch-up we seem to be doing, though, with the ACT government 
recently announcing a scheme for medical marijuana. The plan is to 
"establish the ACT as a leader in the research and development of 
cannabis products . . . and develop a framework for the prescription, 
use and distribution of medicinal cannabis to those who need them on 
medical grounds". The big problem is that medical researchers are not 
clear about who actually needs medical marijuana, and that many 
doctors are anxious about prescribing such products.

Doctors are very used to prescribing medications supported by the 
Pharmaceutical Benefits Scheme (PBS), and detailed prescribing 
information is available to help determine choice and dose.

Canada is a similar country to Australia, and trials of medical 
marijuana have been under way there for a couple of years. Yet while 
Canadian doctors generally express cautious support, they are 
reluctant to prescribe it. It is likely that much of this reluctance 
results from lack of research and a paucity of clear guidance. These 
are issues that the ACT government wants to address, but how 
successful they will be I am rather sceptical about.

This is because medical marijuana is not a single product. Indeed, it 
is very difficult to study because there are up to 60 active 
molecules that could have effects. No medical trial would involve 
giving a patient 60 different tablets!

Before a new medication can be approved for patient use, 
pharmaceutical companies have to provide detailed information about 
toxicity and safety. Data about the way a molecule is metabolised in 
the body in different patients, and potential interactions with other 
medications are all critical to ensure safe use. The Therapeutic 
Goods Administration assesses this information and approves the 
information about prescribing that is provided to doctors.

There are a number of reasons that medical marijuana has not yet gone 
through such processes and trials. The fact that use has been illegal 
proved a strong barrier, but also there would be little financial 
reward for a pharmaceutical company to pursue the trials because 
there would be no profitable patent at the end. But the thought that 
an easily grown substance might be life-changing for sufferers of 
chronic pain, end-stage cancers, or terrible conditions such as 
childhood epilepsy is very enticing.

Unfortunately, the evidence we have has not convinced many 
clinicians. In particular, trials in children need to balance 
short-term effectiveness with the risk of longer-term adverse effects 
on a child's developing brain.

It seems that lots of issues have to be sorted out before medical 
marijuana goes mainstream.

In the meantime, don't expect too much to change. Australians will 
probably continue to win the competition as the heaviest dopesmokers 
on the planet.
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MAP posted-by: Jay Bergstrom