Cannabis sativa
This information has been compiled in response to an influx of questions regarding the use of Cannabis sativa as an antiepileptic medication, since a recent court decision in Ontario confirming a defendant's legal right to use marijuana to try to control seizure disorder.
The Plant
Cannabis sativa is an herbaceous annual with erect, very slightly branched, rough (with grayish-green hairs), angular stems 1-3 metres or more high; bearing numerous opposite (or alternate near the top) palmate leaves of five to seven leaflets (three on the upper leaves) on long thin petioles with acute stipules. The leaves are linear-lanceolate, tapering at both ends, with sharply serrate margins. The upper surface is smooth and dark green; the underside, lighter and downy. Small, green, unisexual flowers are borne on separate plants: males having five almost separate, downy, pale yellowish segments borne on axillary panicles; females having a single, hairy, glandular, five-veined sheath enclosing a smooth, one-celled ovary with hanging ovule and two long, hairy, thread-like stigmas extending beyond the flower for more than its own length, borne in spike-like clusters. The fruit is a small, smooth, light brownish-gray achene. The entire plant smells resinous.
Cannabis sativa is indigenous to Persia, northern India, southern Siberia and China. Formerly, it was extensively cultivated for fibre and oil throughout Asia, Europe and North America, where now it is found as a weed growing in dry, sandy soil.
Historical Uses
Hemp fibre once rivalled cotton for clothing. The best was produced from plants grown in cooler latitudes: Russia, north-central USA and Canada; Italy was once renowned for the quality of its hemp. Before the Second World War, Britain alone imported about 1.5 million hundredweight annually for cordage, sacking, and sail-cloths. Oil for cooking and lighting was pressed from the seeds; a varnish was also made from the remnants. It is said that 2 or 3 green twigs collected in spring and placed in beds will drive bedbugs away from the room!
In 1937, American industry successfully lobbied against growing it in that country.
Medicinal History
Cannabis sativa was official in various European and American pharmacopoeia until the late 1930s. In Britain and elsewhere, only hemp grown in the area north of Calcutta, India, was recognized as official. The USA levied a heavy tax on any active Cannabis sativa, whether grown domestically or imported from Africa, Turkey, Turkestan, Asia Minor, Italy or Spain.
Medicinal Uses
Various catalogues describe Cannabis sativa as: analgesic-hypnotic; topical anaesthetic; antiasthmatic; antibiotic; antiepileptic and antispasmodic; antidepres-sant and tranquilizer; antitussive; appetite stimulant; oxytocic; preventive and anodyne for neuralgia and migraine; aid to psychotherapy; agent to ease withdrawal from alcohol and opiates.
Principal uses of Cannabis sativa in medicine included easing pain, inducing sleep and soothing nervous disorders. It was said to not cause constipation nor negatively affect the appetite as do opiates. It was considered useful in neuralgia, gout, rheumatism, delirium tremens, insanity, infantile convulsions, insomnia, etc. The tincture was used to help parturition, and in senile catarrh, gonorrhoea, menorrhagia, chronic cystitis and all painful urinary affections. An infusion of the seed was used in after-pains and prolapus uteri. The resin was combined with ointments, oils or chloroform for inflammatory and neuralgic complaints. Because the constituents deteriorate rapidly (due to oxidation) and therefore are very variable, it was considered best given in ascending quantities to produce its effect.
Action
Cannabinone (hemp resin) is soluble in alcohol and ether. Cannabinol, an active principle separated from it, is fawn-coloured, in thin layers, and burns with a clear, white flame, leaving no ash. There is a small amount of amber-coloured volatile oil, one of the linseed-oil group. It may be resolved into a colourless liquid (cannabene) and a solid hydride of this. A volatile alkaloid resembling nicotine is found in the tops. It also contains alcoholic extract, ash, and the alkaloid, choline.
The action of cannabis seems to be almost entirely on the higher nerve centres. It can produce intoxication, with hallucinations in large doses. Its medical history suggests that it has only low toxicity, with no confirmed deaths attributed to cannabis poisoning. Cannabidiol (CBD) has been shown to have some anticonvulsant properties. Isomers of tetrahydrocannabinol (THC), the euphorigenic substance of cannabis, have been shown to both cause and suppress seizures.
The Law
At present, both the possession and cultivation of cannabis is illegal in all Canadian jurisdictions, carrying maximum prison sentences of 7 years each. Trafficking may be punished by imprisonment for life.
In other jurisdictions, cannabis has been approved for recommendation by physicians in cases of AIDS/HIV, Alzheimer's disease, cancers, epilepsy, glaucoma and multiple sclerosis. Potential beneficial effects may include increased appetite, weight gain, reduced nausea, reduced anxiety and possible anticonvulsant effects.
Conclusion
Dependable documentation of the effectiveness of Cannabis sativa as an antiepileptic medication is severely limited at this time. Some accounts show a reduction in seizure frequency and/or severity for some people with epilepsy. Whether this is due to anticonvulsant properties of cannabis or to a reduction in physical and/or psychological stress levels is not fully known and cannot be clarified without further comprehensive scientific scrutiny. Potentially negative side effects also need to be considered. Pseudo-scientific "research" (conducted to support political, moralistic or economic positions in approaching this and other once commonly used medicinal plants) does not help anyone with seizure disorder.
Like any drug, cannabis probably has potential to both harm and heal. Without bone-fide scientific investigation and evaluation, the efficacy of Cannabis sativa as an antiepileptic drug cannot be safely or surely ascertained.
For Further Historical Reading
Grieve, Margaret (FRHS). A Modern Herbal: The Medicinal, Culinary, Cosmetic and Economic Properties, Cultivation, and Folklore of Herbs, Grasses, Fungi, Shrubs and Trees, with all their Modern Scientific Names. Jonathan Cape. 1931 (rev. 1994).
Lust, J. (ND, DBM). The Herb Book. Bantam. 1974.
Under no circumstances should any person with seizure disorder change, augment or substitute any prescribed antiepileptic medication for another registered drug or other (alternative, complementary or herbal) treatment without specific instructions to do so from their neurologist or attending physician.
Sudden withdrawal from antiepileptic medications may cause rebound seizures or status epilepticus.
