Pubdate: Fri, 01 Apr 2016
Source: Mail and Guardian (South Africa)
Copyright: Mail & Guardian, 2016
Authors: Charles Parry, Bronwyn Myers & Nandi Siegfried
Note: Professor Charles Parry is the director of the alcohol, tobacco 
and other drug research unit at the Medical Research Council. 
Professors Bronwyn Myers and Nandi Siegfried are chief specialist 
scientists in the same unit.


African regulatory authorities such as the South African Medicines 
Control Council should consider applications to approve medicinal 
cannabis for the treatment of chronic pain.

This is especially needed in the case of patients who are not 
responding well to conventional medication and where the use of 
medicinal cannabis may have a positive effect on its own or as an 
adjunct to existing medications.

But regulatory bodies must be guided by good evidence rather than by 
anecdotal reports or pressure from recreational users promoting a 
legalisation agenda.

Policymakers on the continent, and particularly in South Africa, need 
not be passive consumers of research conducted in Europe and the 
United States. Instead, our researchers should investigate the 
medicinal effects of cannabis in areas where the quality of the 
science to date is poor or where more research needs to be undertaken.

The Medical Research Council is well positioned to take a leading 
role as a conduit for local and international funding of, and support 
for, clinical trials of medicinal cannabis as well as other research 
in this vein.

Through the ages, many cultures have used cannabis as a medicine, but 
in the past 60 years prohibition has hampered research into its 
potential therapeutic effects.

Cannabis is the generic term for drugs produced from the plant 
Cannabis sativa. The principal active ingredient of cannabis is the 
cannabinoid, THC. Chemicals derived directly from the cannabis plant 
or those manufactured synthetically in pill form, like nabilone and 
dronabinol, are known as cannabinoids.

Cannabidiol (CBD), another cannabinoid, is not psychoactive but is 
thought to have anti-anxiety and antipsychotic effects. The 
therapeutic effects of cannabis depend on the concentration of THC 
and the ratio of THC to CBD. Cannabinoids can be ingested orally, 
placed under the tongue, absorbed through the skin in patches or 
balms, smoked, inhaled, used as a suppository or drunk as a herbal tea.

Research has increased substantially over the past decade - but in 
the West, not in sub-Saharan Africa, despite the region's good 
conditions for growing high-quality cannabis products outdoors.

In January the Medical Research Council released a policy brief on 
cannabinoids for medical use, in which we appraised a systematic 
review evaluating the medicinal use of cannabis, first published by 
Dr Penny Whiting and colleagues in the Journal of the American 
Medical Association in June 2015.

The systematic review was commissioned by the Swiss federal office of 
public health and focused on randomised controlled studies evaluating 
cannabinoids for managing 10 conditions, including nausea and 
vomiting linked to chemotherapy, chronic pain, appetite stimulation 
in people with HIV, spasticity caused by multiple sclerosis or 
paraplegia, and glaucoma.

The authors identified 79 eligible randomised controlled studies and 
found evidence of a moderate quality to support the use of 
cannabinoids to treat chronic pain and to reduce spasticity in 
multiple sclerosis patients, but the clinical significance of the 
latter remains unclear. Evidence for a beneficial effect of 
cannabinoids in nausea and vomiting from chemotherapy was low, and 
similarly for weight gain in HIV patients. Safety concerns were 
raised, with some short-term adverse events reported, and the lack of 
long-term data from rigorous studies was noted.

Research to address these gaps will require making medical-grade 
cannabis available for research in various forms, and encouraging 
governments and international agencies to fund both preclinical 
research (cellular-level and animal studies) and human trials.

Support for research into medicinal cannabis must not be contrasted 
with a prohibition agenda against recreational use. Society has not 
forgone the use of morphine for fear of the recreational use of 
heroin. In fact, a study from the US published in 2015 in the Journal 
of Policy Analysis and Management suggests that medicinal cannabis 
policies reduce recreational cannabis consumption, except in states 
that permit dispensaries or home cultivation.

Before medicinal cannabis can be made more widely available, even for 
conditions such as chronic pain, where the evidence of benefit is 
strongest, policymakers will need to consider issues such as the safe 
supply and regulation of medicinal cannabis, the best routes for 
administration, cost-effectiveness and, at a later stage, issues such 
as selection criteria for eligible patients. Training of doctors, 
pharmacists and others in prescribing and administering medicinal 
cannabis and the instruction of patients in its use will also need to 
be developed.
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MAP posted-by: Jay Bergstrom