Medical cannabis



Medical cannabis refers to the use of the drug Cannabis as a physician recommended herbal therapy, most notably as an antiemetic. The term medical marijuana post-dates the U.S. Marijuana Tax Act of 1937, the effect of which made cannabis prescriptions illegal in the United States.

Due to widespread illegal use of cannabis as a recreational drug its legal or licensed use in medicine is now a controversial issue in most countries.

There are many studies regarding the use of cannabis in a medicinal context. . Cannabis was listed in the United States Pharmacopeia from 1850 until 1942, however the United States federal government does not currently recognize any legitimate medical use, although there are currently seven patients recieving cannabis for their various illnesses through a Federal Medical Marijuana program that was closed to new patients by President George H. W. Bush. (See also DEA). Regardless, Francis L. Young, an administrative law judge with the Drug Enforcement Agency, has declared that "in its natural form, (cannabis) is one of the safest therapeutically active substances known".

History
Cannabis has been used for medicinal purposes for over 4,800 years. Surviving texts from Ancient India confirm that its psychoactive properties were recognized, and doctors used it for a variety of illnesses and ailments. These included a whole host of gastrointestinal disorders, insomnia, headaches and as a pain reliever, frequently used in childbirth.

Cannabis as a medicine was common throughout most of the world in the 1800s. It was used as the primary pain reliever until the invention of aspirin. Modern medical and scientific inquiry began with doctors like William Brooke O'Shaughnessy and Jacques-Joseph Moreau de Tours who used it to treat melancholia, migraines, and as a sleeping aid, analgesic and anticonvulsant.

By the time the United States banned cannabis (the third country to do so) with the 1937 Marijuana Tax Act, the plant was no longer extremely popular. One of the main opponents to the bill was the representative of the American Medical Association.

Later in the century, researchers investigating methods of detecting cannabis intoxication discovered that smoking the drug reduced intraocular pressure. 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. In 1972 Tod H. Mikuriya, M.D. reignited the debate concerning marijuana as medicine when he published "Marijuana Medical Papers 1839-1972".

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; many patients only smoke enough to feel the medical effects — many complained that Marinol was more potent than they needed, and that the mental effects made normal daily functioning impossible. In addition, Marinol was far more expensive, costing upwards of several thousand dollars a year for the same effect as smoking a plant easily grown throughout most of the world. Many users felt Marinol was less effective, and that the mental effects were far more disastrous; 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 US 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.

In 2003, the American Academy of Ophthalmology released a position statement asserting that "no scientific evidence has been found that demonstrates increased benefits and/or diminished risks of marijuana use to treat glaucoma compared with the wide variety of pharmaceutical agents now available."

New Mexico
Approved by the United States Food and Drug Administration the study included 250 patients and compared smoked cannabis to oral THC. All participants were referred by a medical doctor and had failed to control vomiting using at least three alternative antiemetics. Patients chose smoking cannabis or taking the THC pill. Multiple objective and subjective standards were used to determine the effectiveness.


 * Conclusion: cannabis is far superior to the best available drug at the time of testing, Compazine, and smoked cannabis is clearly superior to oral THC. "More than ninety percent of the patients who received cannabis... reported significant or total relief from nausea and vomiting".  No major side effects were reported, though three patients reported adverse reactions that did not involve cannabis alone.  The report can be read here.

Tennessee
27 patients had failed on other antiemetic therapies, including oral THC.


 * Conclusion: 90.4% success for smoked cannabis; 66.7% for oral THC. "We found both marijuana smoking and THC capsules to be effective antiemetics. We found an approximate 23% higher success rate among those patients administered THC capsules. We found no significant differences in success rates by age group. We found that the major reason for smoking failure was smoking intolerance; while the major reason for THC capsule failure was nausea and vomiting so severe that the patient could not retain the capsule.

California
A series of studies throughout the 1980s involved 90–100 patients a year. The study was designed to make it easier for patients to enter the oral THC part of the study. Patients who wanted to smoke cannabis had to be over 15 years old (oral THC patients had to be over 5) and use the drug only in the hospital and not at home. Smoked cannabis patients also had to receive rare and painful forms of chemotherapy.


 * Conclusion: Despite the bias towards oral THC, the California study concluded that smoked cannabis was more effective and established a safe dosage regimen that minimized adverse side effects. The full text of the study can be seen here.

Georgia
119 patients that had failed using other antiemetics were randomly assigned to oral THC pills and either standardized or patient-controlled smoking of cannabis.


 * Conclusion: All three categories were successful — patient controlled smokers at 72.2%; standardized smokers at 65.4%; oral THC at 76%. Failure of oral THC patients was due to adverse reaction (6 out of 18) or failure to improve (9 out of 18); failure of smoking cannabis was due to intolerance for smoking (6 out of 14) or failure to improve (3 out of 14).

Citations of modern medical reports on cannabis

 * Official FDA Statement Regarding Claims of Smoked Marijuana as medicine
 * Report on and index of marijuana medical studies by Todd Mikuriya, M.D.]
 * Cannabis-In-Cachexia-Study-Group; Strasser F, Luftner D, Possinger K, Ernst G, Ruhstaller T, Meissner W, Ko YD, Schnelle M, Reif M, Cerny T: Comparison of orally administered cannabis extract and delta-9-tetrahydrocannabinol in treating patients with cancer-related anorexia-cachexia syndrome: a multicenter, phase III, randomized, double-blind, placebo-controlled clinical trial from the Cannabis-In-Cachexia-Study-Group. J Clin Oncol. 2006 Jul 20;24(21):3394-400.
 * Synthetic THC or low doses of cannabis extract administered orally for cancer-related cachexia (anorexia, weight-loss, emaciation) not better than placebo.
 * Janet E. Joy, Stanley J. Watson, Jr., and John A Benson, Jr., "Marijuana and Medicine: Assessing the Science Base", Division of Neuroscience and Behavioral Research, Institute of Medicine (Washington, DC: National Academy Press, 1999).
 * "The accumulated data indicate a potential therapeutic value for cannabinoid drugs, particularly for symptoms such as pain relief, control of nausea and vomiting, and appetite stimulation." and "At this point there are no convincing data to support (the concern that medical marijuana would lead to an increase in recreational use). The existing data are consistent with the idea that this would not be a problem if the medical use of marijuana were as closely regulated as other medications with abuse potential."
 * Index of studies involving marijuana and multiple sclerosis
 * Doblin et al., Marijuana as Antiemetic Medicine: A Survey of Oncologists' Experiences and Attitudes," Journal of Clinical Oncology, Vol. 9, No. 7, July 1991.
 * Khamsi, R: Cannabis compound benefits blood vessels. Nature, 4 Apr 2005 (premium content).
 * THC has been found to combat formation of arterial blockages. A random survey of oncologists found that 44% had illegally recommended marijuana for the control of vomiting and that 48% would do so if it were legal; 54% thought it should be available by prescription.
 * Vinciguerra et al., Inhalation Marijuana as an Antiemetic for Cancer Chemotherapy," The New York State Journal of Medicine, pgs., 525-527, October 1988
 * 56 Patients who had achieved no success with other antiemetics; 72% found success — the study also concluded that smoked marijuana was more effective than oral THC pills.
 * Chang et al., Delta-9-Tetrahydrocannabinol as an Antiemetic in Cancer Patients Receiving High Dose Methotrexate; Annals of Internal Medicine, Volume 91, Number 6, pg. 819-824, December 1979
 * A double-blind controlled study found a 72% reduction in nausea and vomiting; the study also concluded that smoked marijuana was more effective than oral THC
 * Foltin RW, Brady JV, Fischman MW: Behavioral analysis of marijuana effects on food intake in humans. Pharmacol Biochem Behav. 1986 Sep;25(3):577-82.; RW, Fischman MW, Byrne MF: Effects of smoked marijuana on food intake and body weight of humans living in a residential laboratory. Appetite. 1988 Aug;11(1):1-14.; and Greenberg I, Kuehnle J, Mendelson JH, Bernstein JG: Effects of marihuana use on body weight and caloric intake in humans. Psychopharmacology (Berl). 1976 Aug 26;49(1):79-84.
 * These three studies concluded that marijuana increases appetite.
 * Sallan SE, Zinberg NE, Frei E 3rd: Antiemetic effect of delta-9-tetrahydrocannabinol in patients receiving cancer chemotherapy. N Engl J Med. 1975 Oct 16;293(16):795-7.
 * Study concluded that smoked marijuana was more beneficial than synthetic THC for some patients.
 * Donald P. Tashkin, MD, "Effects of Smoked Marijuana on the Lung and Its Immune Defenses: Implications for Medicinal Use in HIV-Infected Patients"; Journal of Cannabis Therapeutics, Vol. 1, No. 3/4, 2001, pp. 87-102
 * "Frequent marijuana use can cause airway injury, lung inflammation and impaired pulmonary defense against infection. The major potential pulmonary consequences of habitual marijuana use of particular relevance to patients with AIDS is superimposed pulmonary infection, which could be life threatening in the seriously immonocompromised patient. In view of the immonosuppressive effect of THC, the possibility that regular marijuana use could enhance progression of HIV infection itself needs to be considered, although this possibility remains unexplored to date."
 * Guy A. Cabral, PhD, "Marijuana and Cannabinoids: Effects on Infections, Immunity, and AIDS"; Journal of Cannabis Therapeutics, Vol. 1, No. 3/4, 2001, pp. 61-85
 * "However, few controlled longitudinal epidemiological and immunological studies have been undertaken to correlate the immunosuppressive effects of marijuana smoke or cannabinoids on the incidence of infections or viral disease in humans. Clearly, additional investigation to resolve the long-term immunological consequences of cannabinoid and marijuana use as they relate to resistance to infections in humans is warranted."
 * Ekert H, Waters KD, Jurk IH, Mobilia J, Loughnan P: Amelioration of cancer chemotherapy-induced nausea and vomiting by delta-9-tetrahydrocannabinol. Med J Aust. 1979 Dec 15;2(12):657-9.
 * In children receiving cancer chemotherapy delta-9-tetrahydrocannabinol (THC) has an antinausea and antivomiting effect.
 * Sallan SE, Cronin C, Zelen M, Zinberg NE: Antiemetics in patients receiving chemotherapy for cancer: a randomized comparison of delta-9-tetrahydrocannabinol and prochlorperazine. N Engl J Med. 1980 Jan 17;302(3):135-8.
 * THC seems to be an effective antiemetic in many patients who receive chemotherapy for cancer and for whom other antiemetics are ineffective.

Harm reduction
Many medical cannabis opponents note that smoked cannabis is harmful to the respiratory system. However, this harm can be minimalized or eliminated by the use of a vaporizer. Vaporizers are devices that vaporize the active constituents (cannabinoids) and the fragrant aromatic substances in the preparation without combusting the plant material and thus causing the formation of toxic substances. Studies have shown that vaporizers can dramatically reduce or even eliminate the release of irritants and toxic compounds. Another way to eliminate the harm associated with smoking is to totally bypass it by oral consumption.

Indications
In the United States, the Federal Food, Drug, and Cosmetic Act makes the Food and Drug Administration (FDA) the sole government entity responsible for ensuring the safety and efficacy of new prescription and over-the-counter drugs, overseeing the labeling and marketing of drugs, and regulating the manufacturing and packaging of drugs. The FDA defines a drug as safe and effective for a specific indication if the clinical benefits to the patient are felt to outweigh any health risks the drug might pose. The FDA has not approved smoked cannabis as a legitimate medicine for any disease.

According to a survey on the perscription of cannabis in California, cannabis is indicated for over 250 conditions. Cannabis is most importantly indicated as an antiemetic for the treatment of nausea and anorexia associated with treatments for cancer, AIDS, and hepatitis. Cannabis also acts as an antispasmodic and anticonvulsant and is indicated for neurological conditions such as epilepsy, multiple sclerosis, and spasms. As an analgesic and an immunomodulator it is indicated for conditions such as migraine, arthritis, spinal and skeletal disorders. As a bronchodilator it is beneficial for asthma. it also reduces the intraocular pressure and is indicated for glaucoma. Cannabis is also used to treat some mood disorders such as post traumatic stress disorder, depression, Obsessive-compulsive disorder, panic disorder, and bipolar disorder. It is also indicated for Premenstrual syndrome, hypertension, andinsomnia.

Despite this, cannabis remains illegal throughout the United States and is not approved for prescription as medicine.

Proponents

 * Dana Rohrabacher - United States Congressman who proposed a bill to stop Department of Justice from arresting medical cannabis patients.
 * Peter McWilliams - Author who used cannabis to relieve pain.
 * Bill Mescher - A South Carolina state senator who proposed legalization of medical cannabis.
 * Keith Stroup - Founder of NORML.
 * Ethan Nadelmann - President of Drug Policy Alliance.
 * Angel Raich - U.S. activist, plaintiff in Gonzales v. Raich.
 * Marc Emery - Cannabis Culture Magazine, former seed merchant facing extradition to the US.
 * Loretta Nall - United States Marijuana party

Opponents

 * Hamid Ghodse - International Narcotics Control Board president.
 * John Walters - Current drug czar of United States.
 * Mark Souder - U.S. Congressman who filed an amicus brief in support of the U.S. government in Gonzales v. Raich. The federal government may ban the use of marijuana even where states approve its use for medicinal purposes).
 * Andrea Barthwell - Former deputy drug czar under George W. Bush.

Pharmacologic THC and THC derivatives
In the USA, the FDA has approved two cannabinoids for use as medical therapies: dronabinol and nabilone. It is important to note that these medicines are not smoked. Dronabinol is a synthetic THC medication, while nabilone is a synthetic cannabinoid, never marketed in the U.S.

These medications are only approved in the setting of failure of previous medications for nausea because of the relatively high likelihood of "psychotomimetic" side effects. The other commonly-used antiemetic drugs are not associated with these side effects.

In 2005, Canada approved Sativex, a plant-derived mouth spray for neuropathic pain of multiple sclerosis sufferers.

Criticism
The medical use of cannabis has drawn critisism and controversy, mostly in the United States. The United States Food and Drug Administration (FDA) issued an advisory against medical marijuana stating that, "marijuana has a high potential for abuse, has no currently accepted medical use in treatment in the United States, and has a lack of accepted safety for use under medical supervision. Furthermore, there is currently sound evidence that smoked marijuana is harmful." . The medical use of cannabis was not accepted by other American groups, For example:, the National Multiple Sclerosis Society , the American Glaucoma Society, the American Academy of Ophthalmology and the American Cancer Society. (Federal Register, 1992).  On June 6, 2005, the U.S. Supreme Court handed down a decision which supported the Federal Government's position against medical cannabis. 

While some claim medical cannabis is effective for a wide spectrum of medical problems, others limit its efficacy to a few specific circumstances. On the other side of the debate, there are those who feel that cannabis simply that the smoked form of the drug no legitimate medical uses, and others who feel that there are theoretical uses that are superseded by more effective treatments using other drugs.

Those who doubt that smoked cannabis has medical value point out that any determination of a drug's valid medical use must be based on the best available science undertaken by medical professionals. The Institute of Medicine, run by the United States National Academy of Sciences and funded by the United States federal government, conducted a comprehensive study in 1999 to assess the potential health benefits of cannabis and its constituent cannabinoids. The study concluded that smoking cannabis is not recommended for the treatment of any disease condition, but did conclude that nausea, appetite loss, pain and anxiety can all be mitigated by marijuana. While the study expressed reservations about smoked marijuana due to the health risks associated with smoking, the study team concluded that until another mode of ingestion was perfected that could provide the same relief as smoked marijuana, there was no alternative. In addition, there are more effective medications currently available. For those reasons, the Institute of Medicine concluded that there is little future in smoked cannabis as a medically approved medication. The report also concluded for certain patients, such as the terminally ill or those with debilitating symptoms, the long-term risks are not of great concern.

In a recent study by the Mayo Clinic, THC was shown to be less effective than standard treatments in helping cancer patients regain lost appetites.

Progress continues to be made in the development of effective antiemetics for cancer patients. 5-HT3 antagonists such as ondansetron, and the new NK-1 antagonist aprepitant have been used extensively in mitigating the nausea of cancer and chemotherapy. Unlike marijuana, these medications are supported by randomized, controlled studies in the medical literature. The necessity of medical cannabis, at least for the control of cancer-related nausea, may be diminishing as scientists develop a more sophisticated understanding of the neurochemical mechanisms underlying nausea.

Legal and medical status of cannabis
Cannabis is in Schedule IV of the Single Convention on Narcotic Drugs, making it subject to special restrictions. Article 2 provides for the following, in reference to Schedule IV drugs:


 * A Party shall, if in its opinion the prevailing conditions in its country render it the most appropriate means of protecting the public health and welfare, prohibit the production, manufacture, export and import of, trade in, possession or use of any such drug except for amounts which may be necessary for medical and scientific research only, including clinical trials therewith to be conducted under or subject to the direct supervision and control of the Party.

This provision, while apparently providing for the limitation of cannabis to research purposes only, also seems to allow some latitude for nations to make their own judgments. The official Commentary on the Single Convention indicates that Parties are expected to make that judgment in good faith.