*Results of short term controlled trials indicate that smoked cannabis reduces neuropathic pain, improves appetite and caloric intake especially in patients with reduced muscle mass, and may relieve spasticity and pain in patients with multiple sclerosis. However, the patchwork of state-based systems that have been established for “medical marijuana” is woefully inadequate in establishing even rudimentary safeguards that normally would be applied to the appropriate clinical use of psychoactive substances. The future of cannabinoid-based medicine lies in the rapidly evolving field of botanical drug substance development, as well as the design of molecules that target various aspects of the endocannabinoid system. To the extent that rescheduling marijuana out of Schedule I will benefit this effort, such a move can be supported.
* Several research/treatment studies were conducted by state departments of health during the late 1970s and early to mid-1980s under protocols approved by the FDA. These open label studies involved patients who had responded inadequately to other antiemetics. In such patients, smoked cannabis was reported to be comparable to or more effective than oral THC, and considerably more effective than prochlorperazine or other previous antiemetics in reducing nausea and emesis.
*In patients with HIV-associated neuropathic pain, cannabis cigarettes of varying concentration and number consumed over a 5-day period significantly reduced pain intensity. Approximately half of patients experienced more than a 30% reduction, which is a standard benchmark for efficacy.
*One independent health assessment of four of the remaining seven patients obtaining cannabis cigarettes through the federal government’s Compassionate Use Treatment IND (see Council report from 1997),1 showed no demonstrable adverse outcomes related to their chronic medicinal cannabis use. Some of cannabis’ adverse effects differ in experienced versus inexperienced users, and it is not clear to what extent the adverse effects reported in recreational users are applicable to those who use cannabis for the self-management of disease or symptoms. Most data on adverse effects has come from observational population-based cohort studies of recreational cannabis users, an unknown portion of whom may be using the substance for medicinal purposes. Adverse reactions observed in short-term randomized, placebo- controlled trials of smoked cannabis to date are mostly mild without substantial impairment. A systematic review of the safety studies on medical cannabinoids published over the last 40 years (not including studies on smoked cannabis) found that short term use was associated with a number of adverse events, but less than 4% were considered serious.
*Although some cannabis users develop dependence, they are considerably less likely to do so than users of alcohol and nicotine, and withdrawal symptoms are less severe.4,79,80 Like other drugs, dependence is more likely to occur in individuals with co-morbid psychiatric conditions. Whether or not cannabis is a “gateway” drug to other substance misuse is controversial and whether the medical availability of cannabis would increase drug abuse is not known. Analysis of trends in emergency room visits for marijuana do not support the view that state authorization for medical cannabis use leads to increased signals of substance misuse. The IOM concluded that marijuana use is not the cause or even the most serious predictor of serious substance use disorders.
*Like tobacco, chronic cannabis smoking is associated with markers of lung damage and increased symptoms of chronic bronchitis. However, results of a population-based case control study of cannabis smokers found no evidence of increased risk for lung cancer or other cancers affecting the oral cavity and airway. Another population-based case-control study of marijuana use and head and neck squamous cell carcinoma (HNSCC) concluded that moderate marijuana use is associated with reduced risk of HNSCC. Furthermore, although smoking cannabis and tobacco may synergistically increase the risk of respiratory symptoms and COPD, smoking only cannabis is not associated with an increased risk of developing COPD.
*Results of these trials indicate smoked cannabis reduces neuropathic pain, improves appetite and caloric intake especially in patients with reduced muscle mass, and may relieve spasticity and pain in patients with multiple sclerosis.
*Marijuana is the most common illicit drug used by the nation’s youth and young adults. However, the fact that cannabis is prone to non-medical use does not obviate its potential for medical product development. Many legal pharmaceutical products that are used for pain relief, palliation, and sleep induction have more serious acute toxicities than marijuana, including death. Witness the evolving series of steps that the FDA has taken in recent months to address the inappropriate use and diversion of certain long-acting Schedule II opioid drugs. However, the patchwork of state- based systems that have been established for “medical marijuana” is woefully inadequate in establishing even rudimentary safeguards that normally would be applied to the appropriate clinical use of psychoactive substances.