The cannabinoids dronabinol (Marinol, and generics) and nabilone (Cesamet) are effectivefor treatment of chemotherapy-induced nausea and vomiting, for which they have been approved in the US. Cannabinoid products may also be effective for second-line treatment of cancer pain and the neuropathic pain and spasticity of multiple sclerosis, but none are currently approved for these indications. Cannabidiol (CBD) alone, which is not psychoactive, may be effective for treatment of epilepsy, but more documentation is required. No adequate studies of cannabis (botanical marijuana) are available for any of these indications.
The Medical Letter on Drugs and Therapeutics : Cannabis and Cannabinoids