Cannabinoids may also play a role in the immune system, although that role remains unclear. Knowledge of cannabinoid biology has progressed rapidly in recent years, making it possible for the IOM to draw some science-based conclusions about the medical usefulness of marijuana. Basic research has revealed a variety of cellular and brain pathways through which potentially therapeutic drugs could act on cannabinoid receptor systems. Such drugs might be derived from plant-based cannabinoids, from compounds that occur naturally in the body, or even from other drugs that act on the cannabinoid system. Most of the identified health risks of marijuana use are related to smoke, not to the cannabinoids that produce the benefits.
Smoking is a primitive drug delivery system.
The one advantage of smoking is that it provides a rapid-onset drug effect. The effects of smoked marijuana are felt within minutes, which is ideal for the treatment of pain or nausea. If marijuana is to become a component of conventional medicine, it is essential that we develop a rapid-onset cannabinoid delivery system that is safer and more effective than smoking crude plant material. For drug development, cannabinoid compounds that are produced in the laboratory are preferable to plant products because they deliver a consistent dose and are made under controlled conditions. The only cannabinoid-based drug on the market is Marinol.