"Cannabis preparations exert numerous therapeutic effects. They have antispastic, analgesic, antiemetic, neuroprotective, and anti-inflammatory actions, and are effective against certain psychiatric diseases. Currently, however, only one cannabis extract is approved for use. It contains THC and CBD [cannabidiol] in a 1:1 ratio and was licensed in 2011 for treatment of moderate to severe refractory spasticity in multiple sclerosis (MS). In June 2012 the German Joint Federal Committee (JFC, Gemeinsamer Bundesausschuss) pronounced that the cannabis extract showed a 'slight additional benefit' for this indication and granted a temporary license valid up to 2015.
"The cannabis extract, which goes by the generic name nabiximols, has been approved by regulatory bodies in Germany and elsewhere for use as a sublingual spray. In the USA, dronabinol has been licensed since 1985 for the treatment of nausea and vomiting caused by cytostatic therapy and since 1992 for loss of appetite in HIV/Aids-related cachexia. In Great Britain, nabilone has been sanctioned for treatment of the side effects of chemotherapy in cancer patients (Box 1).
"In addition to these confirmed indications, there is solid evidence from a large number of small controlled trials that cannabinoid receptor agonists have an analgesic action, particularly in neuropathic pain; however, no country has yet approved their use for this purpose."

Source

Franjo Grotenhermen, Dr. med., and Kirsten Müller-Vahl, Prof. Dr. med., "The Therapeutic Potential of Cannabis and Cannabinoids," Deutsch Arzteblatt International, 2012 July; 109(29-30): 495–501. doi: 10.3238/arztebl.2012.0495
http://www.ncbi.nlm.nih.gov/p…