THERAPEUTIC USE OF CANNABIS

Sir--I disagree with Kelly Morris' (Dec 20/27, p 1828)1 assumption that
"for groups genuinely interested in therapeutic uses, the position is
clear. They are advocating proper trials of individual cannabinoids for
specific disorders". Why not include natural cannabis? This statement
probably would have sounded different if the discussion about therapeutic
potential was not so unfortunately connected to the debate about
legalisation of cannabis and if the pharmaceutical industry were able to
earn as much money from the natural product as from single cannabinoids.

Single cannabinoids are expensive medicaments and are seldom used. Although
we might ignore it as scientists, as physicians we should realise that the
use of illegal natural cannabis products of uncertain quality will continue
as long as there is no easy legal access to cheap medical cannabis
preparations. There have to be strong scientific arguments against the
medical use of the whole plant to justify this unsatisfactory situation.

Talking about "individual cannabinoids for specific disorders" suggests a
selective effect. But neither 9-tetrahydrocannabinol (THC) (Dronabinol) nor
Nabilone act more selectively than a standardised extract of the cannabis
plant. I do not have the impression that the variability of the components
of cannabis, with the exception of THC and cannabidiol, play a major part
in the reproducibility of effects in comparison with other indices. Many
patients with various illnesses profit therapeutically on a daily basis by
reproducing the known medicinal effects of cannabis with illegal
preparations of different origin; this could be carried out more safely
with standardised, carefully produced preparations.

We often forget that cannabis has been an accepted medicament of western
medicine, and that it was available in many countries until some decades
ago. There is still much to learn about cannabis, but that is also true for
single cannabinoids, especially for new synthetic cannabinoid analogues.
Leaving aside the route of administration and the hazards (eg,
contamination) caused by its legal status, I cannot see that the plant as a
whole would cause any more health risks than THC alone would do.

The argument for cannabinoids, versus cannabis, is based on the wish to
restrict those who want cannabis use to be legalised. Maybe it is based on
fear of not being taken seriously by the scientific community, but in fact
this fear may undermine the credibility of the scientific argument.

Franjo Grotenhermen

Arbeitsgemeinschaft Cannabis als Medizin, Maybachstraße 14, D-50670
Køln, Germany

1 Morris K. The cannabis remedy--wonder worker or evil weed. Lancet
1997; 350: 1828.