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Table 1. Summary of Randomized Controlled Trials Examining Marijuana’s Effect on Various Symptoms Symptom Chemotherapy-induced nausea RCTs 3 Patients 43 Finding(s) Smoked cannabis has a modest antinausea effect greater than placebo but less effective than ondansetron. Smoked cannabis and oral THC produced comparable but small increases in caloric intake and weight; viral load was unaffected. Half of the patients experienced a 30% reduction in pain ratings. Half of the patients experienced a 30% reduction in pain ratings. Reduced scores for pain (50%) and spasticity (30%) were observed using high-potency cannabis cigarettes. Smoked cannabis (one 2% THC cannabis cigarette) caused a signiﬁcant reduction in intraocular pressure. Lead Author (Year) Chang, 1979 17 Chang, 1981 18 Levitt, 1984 19 Abrams, 2003 20 Haney, 2005 21 Haney, 2007 22 Wilsey, 2008 23 Ellis, 2009 24 Wallace, 2007 25 Greenberg, 1994 26 Merritt, 1990 27 HIV-related anorexia 3 97 HIV-related neuropathic pain Capsaicin-induced pain Spasticity from multiple sclerosis Intraocular pressure Totals THC, tetrahydrocannabinol. 2 1 2 1 12 89 15 40 18 302 adequate and well-controlled studies must prove the drug’s efficacy, 8 and it is doubtful that the limited data meet that standard. In addition, consideration for a CSA schedule change also requires an adequate number of studies that dem-onstrate the drug’s safety. 8 Such changes must come from the Attorney General through the promulgation of a rule. Most safety information for marijuana comes from studies that examine its nonmedical, short-term, recre-ational use via smoking. 28 Although some studies have implicated medical marijuana as a risk factor for cancer, others have either not identified an increased risk or cite concomitant tobacco smoking as a confounding factor in their analysis. 29-35 Furthermore, although the view of marijuana as a “gateway drug” to more severe, illicit sub-stance abuse has lacked conclusive supporting evidence collected over time, the gateway concept remains a con-troversial point for many medical marijuana critics. 36-38 The role of marijuana in the development or unmasking of mood disorders and psychoses also remains unclear. 39 The clearest message from studies that have examined medical marijuana’s efficacy and safety is that more research is needed to define its efficacy and safety more clearly. statements regarding its use, particularly during the past 4 years (see Table 2 ). 1,7,10,40 These position statements unanimously support an increase in research designed to examine marijuana’s medical uses, which would likely require a change in marijuana’s CSA schedule to allow for a sufficient volume of research studies. Furthermore, with the exception of the Institute of Medicine’s position, 10 the statements uniformly reject the use of smoked cannabis, mainly because of the inferred health risks from inhaling burned hydrocarbons. 1,7 Although AAHPM has not established a position statement regarding its views on the use of medical marijuana or related research, attendees at a session on the topic at the 2011 Annual Assembly expressed interest in exploring such a statement. 2 Summary The politics and therapeutics of medical marijuana are complex and lack uniformity. In some states, a patient may obtain marijuana without facing criminal prosecution after a physician confirms his or her medical need, yet this remains illegal in many other states. Despite differ-ences in state laws governing its criminality, the federal government views marijuana possession as illegal; the US Department of Justice has simply chosen to not enforce federal law in states embracing decriminalization—at least while under the guidance of the current administra-tion. Fortunately, regardless of the state in which they practice, all physicians possess a constitutionally protected right to discuss medical marijuana with their patients. Position Statements on Medical Marijuana In response to growing popular support for the use of marijuana medically, and in recognition of these knowledge limitations, several well-known and reputable medical organizations have developed position Table 2. Summary of Position Statements by Medical Organizations on Medical Marijuana (Cannabis) Organization Institute of Medicine American College of Physicians Approval of Smoked Cannabis ? Yes, conditionally No Support of More Research? Yes Yes Comments Calls for more safety data on smoked cannabis Urges development of safe and reliable delivery systems Encourages use of nonsmoked THC with proven beneﬁt Calls for review to reclassify CSA Class I status Recommends clinical exemption for prescribing physicians Calls for applying “established research standards” to cannabis Discourages cannabis prescribing until research conﬁrms safety and efficacy Lead Authors and Year Joy, 1999 10 ACP, 2008 7 American Medical Association American Society of Addiction Medicine No No Yes Yes, conditionally Calls for special CSA schedule to encourage cannabis research CSAPH 1 Barthwell, 2010 40 THC, tetrahydrocannabinol.