Miscellany . . .
Pages: 38 to 38
Creation Date: 1968/01/01
THE EFFECTS OF CANNABIS
The drug cannabis is more potent in its effects when smoked than when taken orally.
For the first time experiments have been made on man using a single substance of well-identified chemical structure, which is the presumed active principle of cannabis, to establish this fact. The substance is Δ 9-THC (one of the tetrahydrocannabinol isomers).
Isbell and co-workers have studied the marijuana-like activity of this substance together with that of other tetrahydrocannabinol isomers at the Addiction Research Center in Kentucky upon healthy former opiate addicts who had used marijuana by smoking it and were familiar with the effects of the crude drug.
These workers found it was possible to assay the relative potencies of substances causing marijuana-like effects in man. The same results were obtained when the "objective" measure of taking pulse rates was used, and the same when replies were obtained to a questionnaire, this latter being considered a "subjective measure". In both tests Δ 9-THC was found to be more potent when smoked than when it was taken orally.
The Δ 6a and Δ 10a-THC (isomers of Δ 9-THC), cannabidiol dimethyl ether and cannabichromene produced no effects in doses ranging up to 2.5 mg/kg taken orally.
In an experiment using ten patients tolerant to 1.5 microgrammes/kg LSD, no cross tolerance to Δ 9-THC was observed when the latter was taken in a dose of 250 microgrammes/kg by smoking. Isbell and his co-workers concluded that this indicates that the two psychotomimetics probably act by way of different mechanisms. In addition, the mental effects of the two drugs is somewhat different. ( Psychopharmacologia 11, 184, 1967.)
The Division of Narcotic Drugs of the United Nations in Geneva has received several enquiries about certain less-known hallucinogens to which attention has recently been attracted. The following are some data about some of these substances:
STP is 4-methyl-2,5-dimethoxy-amphetamine. According to Smythies et al * this substance shows a longlasting hallucinogenic activity.
TMA is another methoxy-derivative of amphetamine, namely 3,4,5-trimethoxy-amphetamine. This substance is a very active hallucinogen.
Nature 216, 128, 1967.
PMA is yet another methoxy-derivative of amphetamine, namely, 4-methoxy-amphetamine and in its case the strongest hallucinogenic activity has been observed.
These data are taken from a study of Smythies and his co-workers who compared the hallucinogenic activity of STP, TMA and PMA with that of other amphetamine and mescaline derivatives. *
DMT: This substance is dimethyl tryptamine. It produces markedly significant mental effects including anxiety, hallucinations, perceptual distortions and autonomic changes consisting of pupillary dilation, increase of systolic and diastolic blood pressure, and a decrease in the kneejerk threshold.