With recent legalization of medical and recreational marijuana in many states in the US, physicians are often facing questions from their patients regarding the potential harmful effects of this drug on their body. Once known as an illegal substance, marijuana is now legalized for medicinal purposes in many states and for recreational use in Alaska, Washington and Colorado.
Marijuana is made from drying and shredding the leaves and flowers of the plant Cannabis sativa. Tetrahydrocannabinol is the active component which primarily acts on the cannabinoid receptors I and II in the central nervous system and the periphery, respectively. In the United States, it is mostly used in its inhalational form via smoking and is the most commonly used illicit drug.
Medical marijuana plays a crucial role in the management of chronic pain syndromes, glaucoma, multiple sclerosis, HIV especially AIDS associated anorexia and wasting syndrome and epilepsy. With clinical evidence backing the use of marijuana in population with chronic, debilitating conditions, the widespread legalization raises concerns over its safety.
Cannabis has been used for medicinal purposes for over 4,800 years. The documentation of marijuana goes back to the ancient Chinese civilizations, Indian literature and Egyptian pharaohs. 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 aspirinref>http://news.bbc.co.uk/1/hi/programmes/panorama/1632726.stm</ref>. Modern medical and scientific inquiry began with doctors like O'Shaughnessy and 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. Skepticism about marijuana arose in response to the bill. 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. Marinol (Dronabinol), like ingested cannabis, is very psychoactive, and is harder to titrate than smoked cannabis. 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 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 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.
Clinical pharmacology of medical cannabis
Marijuana is classified as a schedule I substance by the FDA. As mentioned above, tetrahydrocannabinol (THC) is the principal compound found in the cannabis plant that is responsible for its psychoactive effects.
- Marijuana acts on the cannabonoid receptors CB-1 and CB-2. The CB-1 receptors are found primarily in the central nervous system. They are found in high density in the basal ganglia, hippocampus, cerebellum, hypothalamus, limbic cortex and the neocortex. The CB-2 receptors are found peripherally in the immune cells and tissues.
- CB-2 receptors are also found on the microglia. These receptors are thus studied as targets in the treatment of Alzheimer's dememtia.
- THC is a strong lipophilic compound. Its distribution phase half life is 0.5 hours, whereas its termination phase half life is variable with mean being around 30 hours owing to its lipophilic properties.
- Smoking marijuana has a bioavailability of 10 to 25% whereas orally consumed THC was found to have a bioavailability of 5 to 20% in clinical studies. Presence of acids in the stomach and first pass elimination in the liver influences bioavailability of ingested THC.
- Peak concentrations of the oral THC is achieved in 1 to 3 hours. This variability is attributed to incomplete and delayed absorption in subjects.
Early studies on efficacy
Approved by the 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.
27 patients had failed on other antiemetics 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 smoked marijuana. We found no significant differences in success rates by age group. The major reason for THC capsule failure was nausea and vomiting so severe that the patient could not retain the capsule."
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 be receiving rare and painful forms of chemotherapy to qualify.
- 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.
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).
Dronabinol, in a single study, may be worse than placebo for neuropathic pain associated with spinal cord injury.
With increasing use of marijuana as a recreational substance in adolescents and recent legalization of its medical use, the concerns over detrimental effects of cannabinoids is a stormy debate. In this article, we will focus on the neuropsychiatric, cognitive, cardiovascular, cerebrovascular and peripheral vascular adverse effects of cannabinoids.
Cardiovascular effects of marijuana
- Literature supports temporal association between marijuana use and development of acute myocardial infarction  , sudden cardiac death and cardiomyopathy. However, the exact mechanism of these effects is unknown. Experts are of the opinion that cannabinoids can have deleterious effects on coronary microcirculation.
- Case reports describe inducible ventricular tachycardia in patients with marijuana abuse and normal coronary anatomy with significant reduction in coronary flow. This slow flow has been shown to revert back to normal and lack of inducible ventricular tachycardia with cessation of marijuana.
- Interestingly, marijuana use may precipitate acute coronary syndrome in those with pre-existing coronary artery disease. It is also associated with 4.2 fold increased risk of mortality in users who reported more than once per week use of the drug.
Cerebrovascular effects of marijuana
- Risk of stroke has been clearly documented in case reports. Mouzak et al. reported transient ischemic attacks (TIA) in marijuana users, suggesting either reversible spasm of cerebral vessels or transient increase in blood pressures.
Peripheral vascular effects of marijuana
- Cannabis arteritis was first described in 1960. Case reports describe proximal arteriopathy of lower limbs leading to tissue necrosis in long standing cannabis users.
- Favorable outcomes on the peripheral vasculopathy after cessation of cannabis in some patients suggest reversible endothelial dysfunction from its use. It is considered to be a form of Buerger's disease.
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 or ingesting the drug in an edible form or other non-smoking modes of delivery like tinctures. Vaporizers are devices that vaporize the active constituents (cannabinoids) and the fragrant aromatic substances in the preparation without combusting the plant material and thus preventing the formation of toxic substances. Studies have shown that vaporizers can dramatically reduce or even eliminate the release of irritants and toxic compounds.
According to a survey on the recommendation 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, clinical depression, obsessive-compulsive disorder, panic disorder, and bipolar disorder. It is also indicated for premenstrual syndrome, hypertension, and insomnia.
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. FDA and comparable authorities in Western Europe in including the Netherlands, have not approved smoked marijuana for any condition or disease.   Cannabis remains illegal throughout the United States and is not approved for prescription as medicine, although 12 states - Alaska, California, Colorado, Hawaii, Maine, Montana, Nevada, New Mexico, Oregon, Rhode Island, Vermont and Washington - approve and regulate its medical use. (The federal government continues to enforce its prohibition in these states.) However, there are also 2 states, Arizona and Maryland, whose drug laws are favourable towards the medicinal use of marijuana,[clarification needed] but which still explicitly ban it.
Notable pro- and anti-medical cannabis individuals
- Mary Lynn Mathre, RN, MSN, CARN. President, Patients Out of Time; Cannabis spokesperson for the Virginia Nurses Association. Editor, "Cannabis in Medical Practice: A Legal, Historical and Pharmacological Overview of the Therapeutic Use of Marijuana."
- Carl Sagan - American astronomer and astrochemist, co-author of Cosmos: A Personal Voyage and author of Contact. In 1969 he wrote an essay titled Mr. X about cannabis in which he said, "the illegality of cannabis is outrageous, an impediment to full utilization of a drug which helps produce the serenity and insight, sensitivity and fellowship so desperately needed in this increasingly mad and dangerous world."
- Ann Druyan - wife of Carl Sagan, one of the writers of Cosmos: A Personal Voyage, producer of Contact. She serves on the NORML board of directors and is president of the NORML Foundation board of directors.
- Willie Nelson - Singer and songwriter.
- William F. Buckley - conservative Republican talking head, publisher of the National Review. Author of Free Weeds 29 Jun 2004, and The Court on High 7 Jun 2005.
- Dennis Peron - co-author of 215, along with Anna Boyce and Scott Imler. Founder of the first Cannabis Club, and in 1995 the 5-story Cannabis Buyers Club at 1444 Market Street (the main street of town) San Francisco.
- Valerie Corral and WAMM
- Scott Imler - along with Dennis, there at the beginning and founder of the West Hollywood Club, which he ran successfully for five years.
- Lanny Swerdlow - founder of the Marijuana Anti-Prohibition Project in Palm Springs
- Gatewood Galbraith - Kentucky attorney; life-long crusader for liberty and human dignity; one of America's leading hemp advocates.
- Angel Raich - U.S. activist, respondent in Gonzales v. Raich.
- Sister Jane Weirick - among other things Sister Jane was a buyer for Dennis at the San Francisco Cannabis Buyers Club. She worked tirelessly until her death, opening the Hayward Patient's Resource Center.
- Ed Rosenthal - A horitcultarist that fights for the right to grow marijuana for medicinal purposes.
- Dr. Jay Cavanaugh - founder of the American Alliance for Medical Cannabis. Gubernatorial Appointment to California State Board of Pharmacy 1980-82, reappointed 1982-86, reappointed to final Constitutional term 1986-90. Assisted in developing and coordinating drug enforcement against pharmacies, wholesalers, and manufacturers, diverting narcotics. Developed and implemented Recovering Pharmacist Program. Assisted in insuring pharmacist consultation with patients.
- Dr. Lester Grinspoon - Author of Marijuana the Forbidden Medicine
- Dr. Tod Mikuriya - Author of The Medical Marijuana Papers, advisor for the Cannabis Buyers Club in San Francisco (and most of the other clubs in the first years) and author of www.mikuriya.com
- Dr. Donald Abrams - Donald Abrams, MD, is Professor of Clinical Medicine at the University of California San Francisco, Chief of Hematology/Oncology at San Francisco General Hospital and Director of Clinical Programs at the Osher Center.
- Fred Gardner - "the chronicler of the movement", published in CounterPunch and other prominent publications and author of O'Shaunessey's, the Journal of the California Cannabis Research Medical Group.
- Steve Kubby - Key Organizer of California's Proposition 215 , Founder and National Director American Medical Marijuana Association.
- Peter McWilliams - Author who used cannabis to relieve pain.
- Rick Steves - PBS Travel Show Host and on NORML's advisory board.
- Rob Kampia - Founder of Marijuana Policy Project.
- Dana Rohrabacher - United States Congressman who proposed a bill to stop Department of Justice from arresting medical cannabis patients.
- Vanessa Nelson - Journalist specializing in covering medical marijuana cases.
- Al Byrne, Co-founder and COO, Patients Out of Time. Co editor, Marijuana as Medicine." (video)
- Bill Maher - Comedian and host of Real Time with Bill Maher on HBO.
- Ethan Nadelmann - President of Drug Policy Alliance.
- Bill Mescher - A South Carolina state senator who proposed legalization of medical cannabis.
- Keith Stroup - Founder of NORML.
- Penn Jillette - Of Penn and Teller. Strong advocate. Has never taken recreational drugs.
- Woody Harrelson - American actor.
- Stephen Jay Gould - American paleontologist and evolutionary biologist.
- Tonya Davis - medical cannabis activist and patient. State Director for Ohio AAMC and medical cannabis director for North Ohio Norml. Writer of the Ohio Compassionate Act
- Montel Williams Television Talk Show Host. Specifically stated as suffering from MS, and medical marijuana being the one thing found to provide relief after trying several prescribed painkillers. Affirmed and advocacy information avaiable from his taking action web page at http://www.montelms.org/TakingAction
- Loretta Nall - Founder of the United States Marijuana party
- Marc Emery - Cannabis Culture Magazine, former seed merchant facing extradition to the US.
Emerging Medical Consensus
Dozens of medical organizations have endorsed allowing patients access to medical marijuana with their physicians' approval. These include, but are not limited to, the following:
- Leukemia & Lymphoma Society - America's second largest cancer charity.
- American Academy of Family Physicians
- American Public Health Association
- American Nurses Association
- British Medical Association
- AIDS Action
- American Academy of HIV Medicine
- Lymphoma Foundation of America
- Health Canada
- Hamid Ghodse - International Narcotics Control Board president.
- John P. Walters - Current Director of the White House Office of National Drug Control Policy 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 director of the White House Office of National Drug Control Policy under George W. Bush.
- Paul Clement - Current Solicitor General who argued on behalf of the federal government in Gonzales v. Raich.
- Dan Lungren - Former Attorney General of California who presided over crackdown of medical marijuana dispensaries.
- Mitt Romney Republican candidate in the 2008 United States presidential election.
- George W. Bush - President of the United States, 2000-2008.
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.
|Medication||Year approved||Licensed indications|
|Nabilone||1985||Nausea of cancer chemotherapy that has failed to respond adequately to other antiemetics|
|Marinol||1992||Nausea of cancer chemotherapy that has failed to respond adequately to other antiemetics, AIDS wasting|
These medications are usually used when first line treatments for nausea fail to work. In extremely high doses and in rare cases there is a possibility of "psychotomimetic" side effects. The other commonly-used antiemetic drugs are not associated with these side effects.
The prescription drug Sativex, an extract of cannabis administered as a sublingual spray, has been approved in Canada for the treatment of multiple sclerosis; this medication may now be legally imported into the United Kingdom and Spain on prescription. Dr. William Notcutt is one of the chief researchers that has developed Sativex, he has been working with GW and founder Geoffrey Guy since the company's inception in 1998. Notcutt states that the use of MS as the disease to study "had everything to do with politics."
On 4-20-2006, 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." . Some prominent American societies have been reluctant to endorse medicinal cannabis. For example: , the National Multiple Sclerosis 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 approved the Federal Government's position that federal law permits the prosecution of persons possessing cannabis regardless of the defense that they are medicinal cannabis patients, even in states that exempt its prohibition for medicinal purposes.. 
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, the study pointed out the inherent difficulty in marketing a non patentable herb. Pharmaceutical companies will not substantially profit unless there is a patent. 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 an unpublished 2001 study by the Mayo Clinic, Marinol was shown to be less effective than megestrol acetate in helping cancer patients regain lost appetites.
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." 
Legal and medical status of cannabis
- 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.
- 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.
- New Studies Destroy the Last Objection to Medical Marijuana
- Patients Out of Time
- Coalition to Reschedule Cannabis
- Health issues and the effects of cannabis
- Ed Rosenthal
- Tilden's Extract
- Victor Robinson
- Steve Kubby
- California Cannabis Research Medical Group
- Cannabis Buyers Club
- Multidisciplinary Association for Psychedelic Studies
- Proposition 215
- Legality of cannabis by country
- MMJ ACTION NETWORK
- Single Convention on Narcotic Drugs 1961, International Narcotics Control Board.
- Dominik Wujastyk, "Cannabis in Traditional Indian Herbal Medicine" in Ana Salema (ed.), Ayurveda at the Crossroads of Care and Cure, Lisbon, Centro de História del Além-Mar, Universidade Nova de Lisboa, 2002, pp.45--73. ISBN 972-98672-5-9. Early pre-publication draft.
- Snedecor SJ, Sudharshan L, Cappelleri JC, Sadosky A, Desai P, Jalundhwala YJ; et al. (2013). "Systematic review and comparison of pharmacologic therapies for neuropathic pain associated with spinal cord injury". J Pain Res. 6: 539–47. doi:10.2147/JPR.S45966. PMC 3712802. PMID 23874121.
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- Cannabis Vaporizer Combines Efficient Delivery of THC with Effective Suppression of Pyrolytic Compounds By D. Gieringer et.al. Journal of Cannabis Therapeutics, Vol. 4(1) 2004, 
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- American Academy of Ophthalmology. Complementary Therapy Assessment: Marijuana in the Treatment of Glaucoma. Retrieved August 2, 2006.
- The Antique Cannabis Book
- Bibliography: Cannabis canadensis. Advances in the History of Psychology, York University
- Cannabis Compassion Corner A not-for-profit online cannabis compassion club.
- DrugScience.org provides scientific and other material regarding the medical use of cannabis.
- Marijuana Ro Medical Club Medical Usage
- Medical Marijuana ProCon.org - Should marijuana be a medical option?
- Waiting to Inhale - The first documentary to examine the movement to legalize cannabis for medical use
- The Debate On California's Pot Shops from CBS news show 60 Minutes
- International organizations
- National organizations
- The Marijuana Policy Project
- Americans for Safe Access
- The Medical Marijuana Museum Medical Cannabis Archive
- American Alliance for Medical Cannabis
- Compassionate Coalition
- Medical Marijuana of America: Resource for pot prisoner support, medicinal cannabis prequalification.
- NORML - National Organization for the Reform of Marijuana Laws Medical Use
- Patients Out of Time
- Local organizations
- Alternative Medicine Outreach Program Douglas County, Oregon
- The BC Compassion Club Society British Columbia
- The Montreal Compassion Center Montreal
- Iowans for Medical Marijuana
- OC Caregivers - Orange County, California
- Rhode Island Patient Advocacy Coalition
- The Wo/Men's Alliance for Medical Marijuana Santa Cruz, California
- WeedConnection Southern California