More than 400 active compounds have been isolated from the C sativa plant. Sixty active compounds are unique to the plant and are collectively known as cannabinoids. Delta-9-tetrahydrocannanbinol (THC) is the most psychoactive cannabinoid, producing euphoria, relaxation, intensification of ordinary sensory experiences, perceptual alterations, diminished pain, and difficulties with memory and concentration.
==Special Precautions of Cannabinoids==
Acute cannabis toxicity results in difficulty with coordination, decreased muscle strength, decreased hand steadiness, postural hypotension, lethargy, decreased concentration, slowed reaction time, slurred speech, and conjunctival injection. Large doses of THC may produce confusion, amnesia, delusions, hallucinations, anxiety, and agitation, but most episodes remit rapidly. Long-term users may experience paranoia, panic disorder, fear, or dysphoria.There is little evidence on the extent of risk for adverse cardiovascular outcomes among cannabis users with pre-existing conditions.
==Health benefits and uses of Cannabinoids==
Cannabis preparations have been used to relieve nausea, improve appetite and reduce pain for thousands of years.1 The development of synthetic drugs in the 20th century supplanted these and other herbal remedies, but in the past several decades there has been a resurgence of interest in using cannabis and cannabinoid preparations for medical purposes. There is evidence from controlled trials that cannabinoids are effective in relieving nausea and vomiting, alleviating acute pain and improving appetite in people with HIV-related disorders. A number of synthetic cannabinoids (e.g., dronabinol) have been approved for medical use in Canada, the United Kingdom and the United States. More recently, a cannabis extract (Sativex) has been provisionally approved in Canada for the treatment of multiple sclerosis. Not all patients have found that the drugs relieve their symptoms, primarily because they find it difficult to control the desired dose of orally administered cannabinoids.2,3 In 2001, the Canadian government responded to demands to allow medical use of smoked cannabis, if authorized by a doctor, among patients experiencing severe symptoms related to cancer, HIV infection, multiple sclerosis and epilepsy.4 Symptoms include nausea, pain, weight loss and persistent muscle spasms and seizures. This decision was made in the absence of strong evidence supporting the efficacy of cannabinoids in many of these applications.