EFFECTIVENESS OF MEDICAL MARIJUANA

Effectiveness of Medical Marijuana

Effectiveness of Medical Marijuana

Marijuana is derived from the hemp plant (Cannabis sativa). Its most important psychoactive chemical, delta-9-tetrahydrocannabinol (delta-l-tetrahydrocannabinol in another nomenclature), is contained in a resin that covers the flower clusters and top leaves of the plant; the resin also contains many chemically related substances with lesser effects. Its preparations vary widely in quality and potency depending on the type of plant, climate, soil, and methods of cultivation and manufacture. The resin can be ingested in the form of a drink or in foods, but usually the leaves and flowering tops are smoked, either in a pipe or in a cigarette called a joint.

Like cocaine and other psychoactive drugs derived from natural plant sources; marijuana has been used for thousands of years as a medicine as well as an intoxicant. It was listed in an herbal published by a Chinese emperor that may go back to 2800 B.C. In Jamaica, where it was introduced in the seventeenth century by African slaves, it has become the most popular folk medicine. Cannabis in the form of an alcoholic tincture was commonly used in nineteenth-century Europe and the United States as an anticonvulsant, sedative, and analgesic, and also in tetanus, neuralgia, uterine hemorrhage, rheumatism, and other conditions. It was thought to be a milder but less dangerous sedative than opium, and it was also considered an appetite stimulant. Between 1839 and 1900 more than a hundred articles appeared in scientific journals on the therapeutic uses of marijuana. After the introduction of injectable opiates in the 1850s and synthetic analgesics and hypnotics in the early twentieth century, the medical use of cannabis declined. But even as late as 1937, extract of cannabis was still a legitimate medicine marketed by drug companies. The Marijuana Tax Act of 1937 imposed a registration tax and record keeping requirements that made medical use of cannabis so cumbersome that it was dropped from the U.S. Pharmacopoeia and National Formulary.

The Marijuana Tax Act was introduced under the influence of a growing concern about the use of marijuana as an intoxicant, especially among blacks and Mexican-Americans in the South and Southwest. The law passed after a strong campaign by the Federal Bureau of Narcotics, despite a lack of empirical evidence on the harmfulness of marijuana. The legislative counsel for the American Medical Association at the time objected to the law, saying that future investigations might show substantial medical uses for cannabis. But the American Medical Association soon changed its stance and for the next thirty years maintained a position on marijuana very similar to that of the Federal Bureau of Narcotics. Recent years have seen some relaxation of legal restrictions and increasing clarification of the medical potential of cannabis and cannabis derivatives, but considerable obstacles remain and considerable research still has to be done.

The greatest advantage of Marijuana as a medicine is its unusual safety. The ratio of lethal dose to effective dose is estimated on the basis of extrapolation from animal ...