Central nervous system effects Cannabis sativa

A9-Tetrahydrocannabinol (A9-THC) is considered to be the predominant compound in preparations of C. sativa (marijuana, hashish, bhang) that is responsible for the central nervous system effects in humans. The recognized central nervous system responses to these preparations include alterations in cognition and memory, euphoria, and sedation. Potential therapeutic applications of cannabis preparations that are of either historical or contemporary interest include analgesia, attenuation of the nausea and vomiting of cancer chemotherapy, appetite stimulation, decreased intestinal motility of diarrhea, decreased bronchial constriction of asthma, decreased intraocular pressure of glaucoma, antirheumatic and antipyretic actions, and treatment of convulsant disorders. These effects have been reviewed recently (Howlett, 1995). 

A -frar s-Tetrahydrocannabinol (THC) is the major psychoactive (euphoriant) constituent of marijuana. Cannabis sativa. The synthetic form of THC (dronabinol) was approved approximately 20 years ago to treat nausea and vomiting associated with cancer chemotherapy, and it has been used for a lesser amount of time to treat appetite loss in patients with HIV/AIDS (44). More recently, an approximately 1 1 mixture of THC and the structurally related marijuana constituent cannabidiol has been approved in Canada for the alleviation of neuropathic pain and spasticity fcr patients with multiple sclerosis and is administered in low doses as a buccal spray (53). Ccnsiderable interest exists in using cannabinoid derivatives based on THC for medicinal purpcses, but it is necessary to minimize the central nervous system effects of these compounds. 

Cannabis sativa plants contain at least 400 different compounds, of which as many as 60 are structurally related to 5 -tetrahydrocannabinol (5 -THC), the primary psychoactive constituent of cannabis. When cannabis is smoked, hundreds of additional compounds are produced by pyrolysis, which may contribute to both acute and chronic effects (Abood and Martin, 1992). The central nervous system actions of canna-binoids are mediated primarily through the CBj receptor. A second type of cannabinoid receptor, termed the CB2 receptor, is distributed primarily in the periphery (Gifford et ah, 1999). Activation of central cannabinoid receptors modulates neurotransmitter release at... 

The opium alkaloids codeine and morphine served as models for the synthesis of naloxone, an important analog used to treat and diagnose opiate addicts, and also led to the discovery of endogenous opioids (enkephalins and endorphins) (see Chapter 47). Similarly, A9-tetrahydro-cannabinol (THC), the component of Cannabis sativa responsible for the central nervous system (CNS) effect, has also been found to reduce nausea associated with cancer chemotherapy (see Chapter 18). 

Delta-9-Tetrahydrocannabinol (Delta-9-THC) and, to a small extent, also Delta-8-THC are the biologically active constituents in extracts of the plant Cannabis sativa (marihuana, hashish) and are responsible for the effects on the human central nervous system (CNS). Potential historical and contemporary therapeutic uses of cannahis preparations include, interalia, analgesia, emesis, anorexia, glaucoma and motor disorders. 

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