Marijuana, antiemetic action

Cannabinoids Marijuana derivatives, including dronabinol [droe NAB i nol] and nabilone, are effective against moderately emetogenic chemotherapy. However, they are seldom first-line antiemetics because of their serious side effects, including dysphoria, hallucinations, sedation, vertigo, and disorientation. In spite of their psychotropic properties (see p. 105), the antiemetic action of cannabinoids may not involve the brain synthetic cannabinoids having no psychotropic activity, nevertheless are antiemetic. 

Nabilone is a synthetic cannabinoid and has properties similar to tetrahydrocannabinol (the active constituent of marijuana) which has an antiemetic action. It is used to relieve nausea or vomiting caused by cytotoxic drugs. Adverse effects include somnolence, dry mouth, decreased appetite, dizziness, euphoria, dysphoria, postural hypotension, confusion and psychosis. These may be reduced if prochlorperazine is given concomitantly. 

Dronabinol (delta-9-tetrahydrocannabinol marinol) is a naturally occurring cannabinoid that can be synthesized chemically or extracted from the marijuana plant. Cannabis sativa. The antiemetic action of dronabinol probably relates to stimulation of the CBj subtype of cannabinoid receptors on neurons in and around the vomiting center. 

Darmani, N.A. (2002a) Antiemetic action of ACtetrahydrocannabinold and synthetic cannabinoids in chemotherapy-induced nausea and vomiting, in Biology of Marijuana Prom Gene to Behavior, E.S. Onaivi, Ed., pp. 356-389. London, U.K. Taylor and Francis. 

Dronabinol (Marinof) [C-ll] [Anriemeric, Appetite Stimulant/ Antivertigo] Uses N/V associated w/ CA chemo appetite stimulation Action Antiemetic 4- V center in the medulla Dose Adults Peds. Antiemetic 5-15 mg/m2/dose q4-6h PRN Adults. Appetite stimulant 2.5 mg PO before lunch dinner max 20 mg/d Caution [C, ] Contra Hx schizophrenia, sesame oil hypersensitivity Disp Caps SE Drowsiness, dizziness, anxiety, mood change, hallucinations, depersonalization, orthostatic 4- BP, tach Interactions T Effects W/ anticholinergics, CNS depressants, EtOH 4- effects of theophylline EMS Use caution w/ sympathomimetics, can T hypertension and tach use caution w/ anticholinergics and antihistamines, can T tach concurrent EtOH use can T CNS depression this is a principal psychoactive substance present in marijuana OD May cause extreme psychiatric effects (anxiety, mood changes and depersonalization) keep pt in a quiet environment and provide reassurance activated charcoal may be effective... 

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