Wikipedia: History of Medical Cannabis

Ancient China

The use of cannabis, at least as fiber, has been shown to go back at least 10,000 years in Taiwan. "Dà má" (Pinyin pronunciation) is the Chinese expression for medicinal cannabis, the first character meaning "big" and the second character meaning "hemp," a pictograph of 2 cannabis plants inside of a house or sheltered area.
Cannabis sativa from Vienna Dioscurides, 512 A.D.

Cannabis, called dà má (??) in Chinese, is known to have been used in Taiwan for fiber starting about 10,000 years ago. Cannabis has been used for medicinal purposes for approximately 4,000 years. In the early 3rd century AD, Hua Tuo was the first known person in China to use cannabis as an anesthetic, which he reduced to powder and mixed with wine.Cannabis was prescribed to treat vomiting, plus infectious and parasitic hemorrhaging.

Ancient Egypt

The Ebers Papyrus (ca. 1,550 B.C.) from Ancient Egypt describes medical marijuana. Other ancient Egyptian papyri that mention medical marijuana are the Ramesseum III Papyrus (1700 BC), the Berlin Papyrus (1300 BC) and the Chester Beatty Medical Papyrus VI (1300 BC). The ancient Egyptians even used hemp (cannabis) in suppositories for relieving the pain of hemorrhoids. The egyptologist Lise Manniche notes the reference to "plant medical marijuana" in several Egyptian texts, one of which dates back to the eighteenth century B.C.

Ancient India

Surviving texts from ancient India confirm that cannabis' psychoactive properties were recognized, and doctors used it for a variety of illnesses and ailments. These included insomnia, headaches, a whole host of gastrointestinal disorders, and pain: cannabis was frequently used to relieve the pain of childbirth.

Medieval Islamic world

In the medieval Islamic world, Arabic physicians made use of the diuretic, antiemetic, antiepileptic, anti-inflammatory, pain killing and antipyretic properties of Cannabis sativa, and used it extensively as medication from the 8th to 18th centuries.

Modern history

An Irish doctor, William Brooke O'Shaughnessy, was held mainly responsible for showing his Western colleagues about the healing properties of marijuana. He was an herb professor at the Medical College of Calcutta, and conducted a marijuana experiment in the 1830s. O'Shaughnessy created preparations and tested animal effects. He continued on to administer this marijuana to patients in order to help treat muscle spasms/stomach cramps or general pain.
An advertisement for cannabis americana distributed by a pharmacist in New York in 1917.

Cannabis as a medicine became common throughout much of the world by the 19th century. It was used as the primary pain reliever until the invention of aspirin. Modern medical and scientific inquiry began with doctors like O'Shaughnessy and Moreau de Tours, who used it to treat melancholia and migraines, and as a sleeping aid, analgesic and anticonvulsant.

By the time the United States banned cannabis in a federal law, the 1937 Marijuana Tax Act, the plant was no longer extremely popular.[15][citation needed] Skepticism about marijuana arose in response to the bill.[citation needed] The situation was exacerbated by the stereotypes promoted by the media, that the drug was used primarily by Mexican and African immigrants.

Later in the century, researchers investigating methods of detecting cannabis intoxication discovered that smoking the drug reduced intraocular pressure.

In 1972 Tod H. Mikuriya, M.D. reignited the debate concerning marijuana as medicine when he published "Marijuana Medical Papers." High intraocular pressure causes blindness in glaucoma patients, so many believed that using the drug could prevent blindness in patients. Many Vietnam War veterans also believed that the drug prevented muscle spasms caused by battle-induced spinal injuries. Later medical use has focused primarily on its role in preventing the wasting syndromes and chronic loss of appetite associated with chemotherapy and AIDS, along with a variety of rare muscular and skeletal disorders. Less commonly, cannabis has been used in the treatment of alcoholism and addiction to other drugs such as heroin and the prevention of migraines. In recent years, studies have shown or researchers have speculated that the main chemical in the drug, THC, might help prevent atherosclerosis.
Medical cannabis card in Marin County, California, U.S.A.

Later, in the 1970s, a synthetic version of THC, the primary active ingredient in cannabis, was synthesized to make the drug Marinol. Users reported several problems with Marinol, however, that led many to abandon the pill and resume smoking the plant. Patients complained that the violent nausea associated with chemotherapy made swallowing pills difficult. The effects of smoked cannabis are felt almost immediately, and is therefore easily dosed. Marinol (Jojel), like ingested cannabis, is very psychoactive, and is harder to titrate than smoked cannabis.[19] Marinol has also consistently been more expensive than herbal cannabis. Some studies have indicated that other chemicals in the plant may have a synergistic effect with THC.

In addition, during the 1970s and 1980s, six U.S. states' health departments performed studies on the use of medical marijuana. These are widely considered some of the most useful and pioneering studies on the subject.[citation needed] Voters in eight states showed their support for marijuana prescriptions or recommendations given by physicians between 1996 and 1999, including Alaska, Arizona, California, Colorado, Maine, Nevada, Oregon, and Washington, going against policies of the federal government.
Cannabis female flowers closeup with trichomes (white). These plant parts contain the highest concentration of medicinal compounds.

In May 2001, "The Chronic Cannabis Use in the Compassionate Investigational New Drug Program: An Examination of Benefits and Adverse Effects of Legal Clinical Cannabis" (Russo, Mathre, Byrne et al) was completed. This three-day examination of major body functions of four of the five living US federal cannabis patients found "mild pulmonary changes" in two patients.

On October 7, 2003, a patent (#6,630,507) entitled: "Cannabinoids as Antioxidants and Neuroprotectants" was awarded to the United States Department of Health and Human Services, based on research done at the National Institute of Mental Health (NIMH), and the National Institute of Neurological Disorders and Stroke (NINDS). This patent claims that cannabinoids are "useful in the treatment and prophylaxis of wide variety of oxidation associated diseases, such as ischemic, age-related, inflammatory and autoimmune diseases. The cannabinoids are found to have particular application as neuroprotectants, for example in limiting neurological damage following ischemic insults, such as stroke and trauma, or in the treatment of neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease and HIV dementia."

Historian Jacob Appel has argued that the medicinal marijuana movement bears striking similarities to the medicinal beer movement of the 1920s. Both efforts attempted to muster medical expertise in the face of a national Prohibition and both pitted the rights of physicians against the authority of the federal government.

Source: http://en.wikipedia.org/wiki/Medical_Cannabis