Cannabis research has led to the development of synthetic cannabinoids. These lab-based alternatives to the naturally occurring cannabinoids found in marijuana have been shown to help patients cope with pain, improve appetite and reduce the effects of cancer treatment. But despite their chemical similarities, plant-based cannabinoids and synthetic cannabinoids are not the same.
When research into the effects of cannabis began, scientists identified and isolated the plant's compounds to find those that may be beneficial. They found that marijuana contains about 85 active cannabinoids. Two of these, tetrahydrocannabinol (THC) and cannabidiol (CBD), have been widely studied. They have been shown to:
As a result of studies into the medical efficacy of cannabis, synthetic forms of these compounds were developed. The idea was to eliminate the negative effects of the naturally occurring cannabinoids -- the high and addiction potential -- while improving the health benefits through dosage control and the removal of impurities.
The Federal Drug Administration has approved two synthetic THC medications, dronabinol (Marinol®) and [nabilone](http://pubchem.ncbi.nlm.nih.gov/compound/Nabilone# section=Top) (Cesamet®) for medical use. Dronabinol is approved for nausea and vomiting related to chemotherapy and as an appetite stimulant in AIDS patients. Nabilone is used to treat nausea and vomiting.
Isolating one single compound, however, eliminates any collaborative effects of the naturally occurring compounds. For example, researchers have reported that the antiemetic effects of THC are enhanced, and side effects are reduced, when taken with CBD. Another study found that the combination of THC and CBD improved results of radiation treatment for glioma, a type of brain cancer. Similarly, Sativex, a cannabis plant-derived medication containing both THC and CBD, has been approved in Canada and other countries for treating pain and spasticity in multiple sclerosis patients.
Another problem with synthetic cannabinoids is delivery method. For example, dronabinol, a gelatin capsule, is ingested. For those suffering from nausea or wasting, it may be difficult to keep pills down or to swallow them. Inhaled cannabinoids may offer an alternative.
Delivery method also influences drug effects. With an ingested cannabinoid, onset of action is about 30 to 60 minutes after it is taken. With inhaled medication, effects can be felt in minutes.
More research is needed into the symbiotic relationship of the naturally occurring cannabinoids and how they compare to the synthetic medications. The most important goal is providing access to patients who could benefit from medical marijuana because they are not getting relief from current medications.