Cannabis : it is time to lift the taboo      (Also available in French)

    MS Kontakt 2000; (2):8-9

    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% of  the 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 of  preparation and administration are being examined.

    Cannabis and MS

    Many studies, even when they are few and  criticised for the level of their methodology, show the favourable effects on spasticity.

    The following table summarises these results: 

    Form and dose

    Type of study





    112/233 MS pat

    97% reduced spasticity and pain

    Consroe 1997


    clinical study

    1 patient

    reduced spasticity and improved ataxy

    Meinck, 1989



    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


    Placebo 9 pat.

    improved spasticity

    Petro, 1981

    THC oral


    Placebo 13 pat

    subjective improvement but not objective

    Ungerleider, 1987

    THC oral


    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.


    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 of  given information to motivate  further studies  to 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 introduce cannabis amongst the multitude of available drugs.

    Dr Renй Metz,



    (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.




    18 August 2000