NORML New Zealand: working for marijuana law reform - Vapourisers for smokeless inhalation

NORML NEWS SUMMER 2008. BY JONATHAN RENNIE

Inhalation of cannabis provides optimal dose delivery due to its rapid action and easy titration. However this usually requires smoking, which raises separate health issues. This can be overcome by the use of vapourisers, which allow lung delivery without smoking. Moreover, it should be noted that especially for those suffering from terminal illnesses, the cumulative damage caused by smoking is of minor concern. It would seem pernicious to deprive them of relief in deference to anti-smoking sentiment.

Smoking & Lung Cancer

Because cannabis smoke contains similar carcinogens to tobacco smoke, it has long been suggested that the cannabis smokers would begin to suffer from increased lung cancer incidents . However a substantial recent epidemiological study has failed to support this prediction. The 2005 study of over 2,000 people found no increase in lung cancer risk for marijuana smokers.

The research, presented to the May 2006 meeting of the American Thoracic Society in San Diego, was lead by pulmonary scientist Donald Tashkin of the University of California, Los Angeles, who had previously conducted research that predicted a carcinogenic effect from cannabis smoking. But looking at residents of Los Angeles County, he found that even those who smoked more than 20,000 joints in their life did not have an increased risk of lung cancer.

After controlling for tobacco, alcohol and other drug use as well as matching patients and controls by age, gender and neighbourhood; marijuana smoking could not be linked to lung cancer. In fact, in some data groups, cannabis-only smokers fared better than non-smokers. Tashkin conceded that the results suggest cannabis smoking could even be protective against lung cancer and speculated that this may be due to the anti-tumoural actions of various cannabinoids.

Smokeless Delivery

Although fears that cannabis smoking leads to lung cancer are probably unfounded, there are other respiratory problems associated with smoking which are clearly best avoided. However, a safe and effective alternative form of inhalation exists.

Vapourisation involves heating cannabis until the resins evaporate, but without burning the solid plant matter. The cannabinoids are inhaled as a vapour, not smoke. Doses can be delivered through the lungs without the combustion of plant matter.

A recent study (Abrams et al, 2007) at the University of California examined the effectiveness of vapourisers and found peak plasma concentrations and bioavailability of THC were similar to smoking. But unlike smoking, vaporisation did not increase the amount of carbon monoxide in the lungs. Researchers concluded vapourisation of cannabis is “a safe an effective mode of delivery of THC.”

Another recent study, by Mitch Earlywine and Sara Barnwell at the University of New York, found vapouriser users were 60 per cent less likely than smokers to report respiratory symptoms such as coughing or phlegm. The report noted “the impact of a vaporizer was larger as the amount of cannabis used increased. These data suggest that the safety of cannabis can increase with the use of a vaporizer. Regular users of joints, blunts, pipes, and water pipes might decrease respiratory symptoms by switching to a vaporizer.”

Vapouriser technology is constantly improving, both in terms of effective dose delivery and ease of use. A number of models are available, with their popularity as a safer alternative to smoking steadily increasing among medicinal and recreational users alike. It would be a small step for the Ministry of Health to approve and supply a standard vapouriser model for prescribed medicinal marijuana use.