Medical cannabis, or medical marijuana, is cannabis and cannabinoids that are recommended by doctors for their patients. The use of cannabis as a medicine has not been rigorously tested due to production restrictions and other governmental regulations. Limited evidence suggests cannabis can: reduce nausea and vomiting during chemotherapy, improve appetite in people with HIV/AIDS, and reduce chronic pain and muscle spasms.
Short-term use increases the risk of both minor and major adverse effects. Common side effects include dizziness, feeling tired, vomiting, and hallucinations. Long-term effects of cannabis are not clear. Concerns include memory and cognition problems, risk of addiction, schizophrenia in young people, and the risk of children taking it by accident.
The Cannabis plant has a history of medicinal use dating back thousands of years across many cultures. The use of medical cannabis is controversial. A number of medical organizations have requested removal from the list of Schedule I controlled substances followed by regulatory and scientific review. Others such as the American Academy of Pediatrics in 2015 opposed the legalization of medical cannabis.
Medical cannabis can be administered using a variety of methods, including liquid tinctures, vaporizing or smoking dried buds, eating cannabis edibles, taking capsules, using lozenges, dermal patches or oral/dermal sprays. Synthetic cannabinoids are available as prescription drugs in some countries; examples include: dronabinol and nabilone. Recreational use of cannabis is illegal in most parts of the world, but the medical use of cannabis is legal in certain countries, including Austria, Canada, Czech Republic, Finland, Germany, Israel, Italy, the Netherlands (where it is also essentially legal recreationally), Portugal and Spain. Australia has passed laws to allow the use of marijuana for medical and scientific purposes in some states. In the United States, 29 states and the District of Columbia have passed legislation permitting the possession, use, and distribution of medical cannabis in some form. Although cannabis remains prohibited for any use at the federal level, the Rohrabacher–Farr amendment was enacted in December 2014, limiting the ability of federal law to be enforced in states where medical cannabis has been legalized.