PUBLIC HEALTH by Ross ColquhounNews Weekly
Case for legalising cannabis up in smoke
, June 20, 2015
The question of whether cannabis is harmless or even has therapeutic properties and should therefore be freely available is one for medical and scientific evidence to establish.
It is not an issue for politicians to decide based on political objectives or for pro-drug groups to undermine the medical evidence or the majority views opposing illicit drug use through relentless media campaigns. According to the 2013 National Drug Strategy Household Survey, a survey of more than 24,000 Australians, 90 per cent of Australians did not approve of the recreational use of cannabis.
After rigorous examination of all the facts, the case put by pro-cannabis advocates to have the drug downgraded from Schedule 1 (a drug of addiction prohibited for use for all purposes) in the US has been rejected. A District Court Judge, who was expected to find in favour of downgrading the drug, recently ruled that the continued classification of cannabis as a Schedule 1 drug was justified.
Drug Free Australia and others have for some years now been presenting the same medical and scientific evidence to inquiries in Australia. Politicians have either not understood the harm associated with cannabis use or decided to ignore it. They have decriminalised its use in some states and have approved trials for medical use in other states.
Cannabis has consistently failed to meet any legal standard that would allow authorities to decide it is not a harmful drug and should not be prohibited. It has never been established that it safe to use as a medicine for certain ailments let alone that it should be allowed for unfettered social use. If its use cannot be justified for medical purposes (where any side effects may be outweighed by the medical benefits) then the case to decriminalise or regulate its use, and to downgrade its classification as a prohibited drug, has no rational argument to sustain it.
The court found that cannabis has a high potential for abuse as it is addictive, it is harmful and there are no acceptable standards for its use, medical or otherwise, and that there is no accepted medical use for it. Moreover, unlike any approved medication, smoking it means that dosage is uncontrolled and therefore strength of dosage is unknown, making it unacceptable to medical authorities and the community.
Crude cannabis contains hundreds of chemicals. Smoking cannabis causes full and partial oxidation of thousands of chemicals, many of them toxic and carcinogenic, including tars, polycyclic hydrocarbons and aromatic amines similar to those found in tobacco smoke. No regulatory authority in the world (for example, the Food and Drug Administration (FDA) in the US or the Therapeutic Goods Administration (TGA) in Australia) acknowledges any smoked preparation as a valid form of dosing of any medication.
Moreover, the cannabis plant contains some 400 chemicals that vary with habitat, making it impossible to standardise and it is often contaminated with microbes, fungi or pesticides.
The harm associated with cannabis use is well documented and irrefutable. Studies have shown that long-term use of cannabis affects memory, concentration, decision-making, coordination, psychological functioning, respiratory health and fertility, and that these effects have been shown to be worse in adolescents. There is some evidence of increased risk of psychosis.
Drug Free Australia has argued that there are at present TGA-approved alternatives to smoked or vaporised cannabis in the form of isolated tetrahydrocannabinol (THC), THC-cannabidiol (CBD) mixtures, CBD alone and other plant-derived and synthetic cannabinoids that have been found useful as medicines. These types of preparations have been legally used in Australia since the mid-1990s, when the THC capsule developed in the US called Marinol was imported into Australia under TGA Special Access for 100 patients. Marinol can be imported today under the same arrangement.
Alternatively, the whole-leaf extract of cannabis, called Sativex, was approved by the Australian TGA in 2012 for MS spasticity. Both medications are pharmaceutically standardised in terms of dosage, strength and purity, which crude cannabis products are not.
Clinical trials have previously shown promise, for both medications can be used for nausea, AIDS wasting, chronic pain and MS spasticity.
A third pharmaceutical medicine which is high in CBD, Epidiolex, is being tested in the US and could be tested here under similar arrangements. CBD is the component within cannabis believed to be responsible for the relief of severe seizures in epilepsy-like syndromes for some sufferers, including children.
There is consequently no need to legalise crude cannabis in Australia. Drug Free Australia has suggested that if it can be proven that other medicines are not better to treat specific ailments, then these cannabis derivatives should be listed under PBS rules to allow ready access for those who need them.
If the pro-cannabis lobby believed that the easier case to win was to win its approval as a medication, then it has failed. Rather, the evidence is overwhelming that for any purpose cannabis is properly prohibited and should remain so.
A recommended recent publication to get all the facts on cannabis is Quit Cannabis by Professor Jan Copeland (Allen and Unwin, 2015)
Dr Ross M. Colquhoun is an executive member of Drug Free Australia and research fellow and a member of the Drug Advisory Council of Australia.