Smoking cannabis is just as harmful as smoking tobacco. It can cause lung complaints and possibly lung cancer. You are therefore advised not to smoke medicinal cannabis.
Vaporised cannabis results in rapid absorption, it enters your bloodstream via your lungs within minutes of inhaling it. You can begin to feel the effects of cannabis within 2 to 10 minutes.
Cannabis is heated at a lower temperature than smoking, producing fewer toxins and no sidestream smoke, making passive smoking less of a problem. Inhalers vaporise the cannabis compounds (cannabinoids, terpenoids and flavonoids) at temperatures between 170 and 210 degrees celsius whereas smoking cannabis combusts at 230 degrees celsius which leads to the inhalation of myriad polynuclear aromatic hydrocarbons (PAHs) which are by-products of combustion and often carcinogenic. Compared to smoking, consistent, reproducible THC extraction is possible, delivering higher therapeutic levels of THC.
For vaporisation to be truly effective, the cannabis product used with it must be of pharmaceutical quality. A fully standardised cannabis flower assures dosage composition, repeatability, and the ability for the patient and prescriber to effectively adjust dose by titration.
Cannabis-based medicines consumed in the oral form, such as oils or liquid capsules, are more slowly absorbed than products administered by vaporising. They take at least 30 to 90 minutes before any effects are felt.
Bioavailability of oral cannabinoids is lower (10 to 20 per cent) because of intestinal and first pass liver metabolism.
Peak effects can occur two to four hours after consumption. Given the longer time frame for
peak effects, it is important to allow at least three hours between administration of single oral doses to avoid possible overdose. Effects can last for up to eight hours and as long as 24 hours.
This may be of particular importance in relation to the timing of SACT in order to get the maximum benefit. Given the slower onset and longer duration, it is expected that taking cannabis-based products via the oral route would be more useful for medical conditions or symptoms where control over longer periods of time is sought — similar to the use of slow release medications
(Queensland Health, 2017).