ABSTRACT

The acute toxicity of cannabinoids is extremely low: they are very safe drugs and no deaths have been directly attributed to their recreational or therapeutic use. Centrally acting cannabinoids such as Δ9-Tetrahydrocannabinol and nabilone generate the majority of unwanted effects; adverse effects relevant to the therapeutic uses of cannabinoids are summarised. Whether the recreational use of cannabis encourages escalation of dosage and progression to other dependence-producing drugs remains debatable. In addition to the many chemical compounds which make up the cannabis plant, street and illicit cannabis can contain both adulterants added by those cultivating and processing the plant and naturally occurring contaminants such as microbes and fungi. Some of the psychological effects of psychoactive cannabinoids experienced by patients, particularly dysphoria and anxiety, could probably be minimised by preparation, explanation and reassurance given before the start of treatment.