With
its famous leaf in the form of a hand with seven fingers, Cannabis sativa is an
annual herb of the cannabinacee family originating from the
central Asia. Hemp grows in all latitudes and it can be cultivated
in most temperate and tropical regions of the whole world. Its
principal agent is the tetra-hydro-cannabinole D9 (THC),
especially available in the resin. The resin is to be found
specifically in the tip of flowers and the female plants are two
times richer in THC than the male ones. The most concentrated
product is the oil of hashish which contains 70% ofthe THC. The resin
(hashish) can contain 25% of THC whereas in marijuana (also called
grass), the dried leaves and tips of flowers of the plant, contain
between 2 and 25%, depending where the plant has grown. THC may
have mood elevating, stimulating, muscle-relaxant, anti-epileptic,
and antalginetic effects; it may also relieve nausea, stimulate
the appetite, relieve bronchospasm and reduce blood pressure.
THC
is one of the 60 aromatic hydrocarbons of hemp called cannabinoids
and it is probably responsible for the majority of the
pharmacological effects. In order to produce their effect in man,
there has to be specific receptor in the human body capable of
reacting to the cannabinoids (two receptors have been identified
CB1 and CB2).
Cannabis
is usually smoked with toxic results equal to the cigarette
smoking (carcinogenic, destruction of mucus in the bronchi,
diminution of the antibacterial activity of macrophages). Oral
administration diminishes these harmful effects but does not seem
to be fully trusted due to the different individual variations of
absorbing of the gastro-intestinal tract. More secure ways ofpreparation and
administration are being examined.
Cannabis and MS
Many studies, even when they are few andcriticised for the level
of their methodology, show the favourable effects on
spasticity.
The
following table summarises these results:
Form
and dose
Type
of study
Result
Ref:
Marijuana
postal
112/233
MS pat
97%
reduced spasticity and pain
Consroe
1997
Marijuana
clinical
study
1
patient
reduced
spasticity and improved ataxy
Meinck,
1989
Marijuana
double-blind
Placebo
10 pat.
better;
but balance problems
Greenberg,
1994
THC
oral
open
study
8
patients
5
subjective improvements
2
objective diminishments of trembling
Clifford,
1983
THC
oral
double-blind
Placebo
9 pat.
improved
spasticity
Petro,
1981
THC
oral
double-blind
Placebo
13 pat
subjective
improvement but not objective
Ungerleider,
1987
THC
oral
Placebo
1 MS
patient
improvement
during the treatment
Martyn,
1995
A study published on 2 March 2000 in ‘Nature’ confirms the
effect of four cannabinoids on spasticity and trembling in an
experimental form of MS in mice.Similar by-products could
be developed for human use.
Debate
For a healthy debate one should not mix the
therapeutic use of cannabis by MS patients and its common use for
the leisure purposes.
From
the medical point of view there is sufficient amount ofgiven information to
motivatefurther
studiesto examine
positive effects of oral cannabis on spasticity in MS. A similar
study on 660 MS patients in Great Britain has just begun and it
looks to me a good start to begin to favourably introducecannabis amongst the multitude
of available drugs.
Dr Renй Metz, Neurologist
, Luxembourg
(Reproduced with kind permission)
NB.
The Cannabinoids in Multiple Sclerosis Study is being conducted by
Dr John Zajicek of the University of Plymouth, UK. Information
about this trial can be found at
this link.