September 2015 | Douglas Mossman, MD
This article hits 3 topics:
• the intersection of marijuana policy and health care in the United States
• the risks and possible benefits of marijuana use
• the medicolegal problems faced by physicians who might advise patients to use marijuana.
Two cannabinoids—dronabinol and nabilone—have received FDA approval as appetite enhancers and anti-nausea agents. Third-party payors usually cover these types of medications, but no insurer pays for medical marijuana.1 The Controlled Substances Act of 19702 classified marijuana as a Schedule I drug because of its abuse potential, lack of accepted medical applications, and uncertain safety. The FDA has not approved marijuana use for any medical condition.
Although people commonly speak of “prescribing” marijuana, physicians cannot legally do this in the United States. What physicians may do, in the 23 states that allow medical marijuana, is recommend or certify a patient’s marijuana use—an action that has constitutional protection under the First Amendment’s freedom of speech clause.3,4
A physician may complete documentation that a patient has one of the qualifying medical conditions for which the jurisdiction has legalized medical marijuana. Either the patient or the physician then submits that documentation to the appropriate government agency (eg, the state’s department of health).
If the documentation receives approval, the agency will issue the patient a registration card that allows possession of medical marijuana, with which the patient can obtain or grow a small amount of marijuana. The cannabinoid content of marijuana products varies considerably,5 and physicians who certify marijuana typically defer dosage recommendations to the patient or the dispensary.1
In states that allow medical marijuana, users may assert an affirmative defense of medical necessity if they face criminal prosecution.3,6 Possession of marijuana remains illegal under federal law, however, regardless of one’s reason for having it.7,8 Since October 2009, the Attorney General’s office has discouraged federal prosecutions of persons “whose actions are in clear and unambiguous compliance with existing state laws providing for the medical use of marijuana.”9 But given the remaining conflicts between state and federal laws, “the legal implications of certifying patients for medical marijuana remain unclear.”10
Physicians have few resources to instruct them on the legal risks of certifying medical marijuana. When Canada legalized medical marijuana, the organization that provides malpractice insurance to Canadian physicians told its members that “prescribing medical marijuana cannot be compared to prescribing prescription drugs” and recommended that physicians obtain signed release forms documenting that they have discussed the risks of medical marijuana with patients.11 For some risky approved drugs, the FDA has established a risk evaluation and mitigation strategy, but no such guidance is available for marijuana.
Highlighting the benefits and risks
Proponents of medical marijuana claim that Cannabis can help patients, and dispassionate experts acknowledge that at least modest evidence supports the benefits of using “marijuana for nausea and vomiting related to chemotherapy, specific pain syndromes, and spasticity from multiple sclerosis.”10 For several other conditions— HIV/AIDS, depression, anxiety disorders, sleep disorders, psychosis, Tourette syndrome—evidence of benefit is poor.12 Rigorous evaluation of medical marijuana is difficult because the plant contains hundreds of active chemical compounds. The chemical content of marijuana is highly variable, depending on its preparation and administration,10,13—one reason why only a few good randomized controlled trials of marijuana have been conducted.
Marijuana use impairs driving ability.14 Following enactment of more lenient marijuana laws, several states have reported higher numbers of fatally injured drivers who tested positive for Cannabis21-23 and had a positive screen of tetrahydrocannabinol (THC) in driving under the influence cases.24,25 One study showed that a blood THC concentration >5 ng/mL (comparable to a blood alcohol concentration of 0.15%) increased the crash odds ratio to 6.6.25,26
Marijuana impairs reaction time, information processing, motor performance, attention, and visual processing.14,16,27,28 Drivers who are under the influence of marijuana make more driving errors, despite being cautious about how they react to traffic.29 Even after weeks of abstinence, previous daily users of marijuana display some cognitive processing and driving-related impairments.30,31
Courts have found physicians negligent if their patients’ treatment-induced driving impairments injured others when the risk of driving-related injury was foreseeable.32 The Massachusetts case of Coombes v Florio33 likened the physician’s duty to that of a liquor store that sells alcohol to a minor who subsequently crashes, or to a father who did not lock his firearms away from his violent adult son.
Three variables influence a court’s judgment about whether risk is “foreseeable”: “the relative knowledge of the risk as between lay persons and physicians, whether the patient has previously used the medication and/or experienced the adverse effect, and whether a warning would otherwise have been futile.”34 A physician who certified a patient to use marijuana without adequately explaining the risks of driving might be vulnerable to a lawsuit if the patient’s driving accident occurred while the patient was under the influence of the drug. Recommending marijuana as a treatment also could lead to a malpractice action if a patient experienced and was harmed by the drug’s adverse effects.
Another malpractice risk stems from marijuana’s addiction potential. Although many people think Cannabis isn’t addictive, nearly 10% of all marijuana users develop dependence.10,17 Regular Cannabis users are more likely to use alcohol, tobacco, and “recreational” drugs,17,35 and using alcohol and marijuana together greatly heightens the risk of driving accidents.14,15 Although we know of no case that relates directly to marijuana, physicians have faced lawsuits for injuries stemming from a patient’s addiction to prescription drugs,36 particularly when the patient’s behavior should have led the physician to suspect abuse or overuse.37
When certifying marijuana use, physicians have the same obligations that apply to more conventional medical treatment:
• establishing a proper physician–patient relationship
• taking an appropriate history
• conducting a proper examination
• reviewing records
• developing a comprehensive treatment plan
• weighing risks and alternatives
• providing follow-up care.
Neglecting these steps could lead to medical board sanctions and suspension or revocation of a medical license.13
The blunt reality
We advise against recommending marijuana for your patients. But if you have exhausted the alternatives, see marijuana as the last resort, and believe that taking the risk is worth the potential benefit, you can take some steps to reduce your legal risk.
Medical marijuana is a controversial topic that demands more rigorous research and regulatory consideration. In the present climate, cautious physicians will avoid recommending marijuana to their patients. If you think that a patient has a medical indication, with no treatment option better than medical marijuana, be sure to understand the medical and legal ramifications before you authorize its use.
The authors report no financial relationship with any company whose products are mentioned in this article or with manufacturers of competing products.
1. Hill KP. Medical marijuana for treatment of chronic pain and other medical and psychiatric problems: a clinical review. JAMA. 2015;313(24):2474-2483.
2. Controlled Substances Act title 21, §801.
3. Frezza C. Medical marijuana: a drug without a medical model. Georgetown Law J. 2013;101:1117-1145.
4. Conant v Walters, 309 F3d 629, 637 (9th Cir 2002).
5. Vandrey R, Raber JC, Raber ME, et al. Cannabinoid dose and label accuracy in edible medical cannabis products. JAMA. 2015;313(24):2491-2493.
6. Thompson AE. JAMA patient page. Medical marijuana. JAMA. 2015;313(24):2508.
7. United States v Oakland Cannabis Buyers’ Cooperative, 532 U.S. 483 (2001).
8. Gonzales v Raich, 545 U.S. 1 (2005).
9. Ogden DW. Memorandum for selected United States Attorneys on investigations and prosecutions in states authorizing the medical use of marijuana. http://www. justice.gov/opa/blog/memorandum-selected-united-state-attorneys-investigations-and-prosecutions-states. Published October 19, 2009. Accessed July 11, 2015.
10. D’Souza DC, Ranganathan M. Medical marijuana: is the cart before the horse? JAMA. 2015;313(24):2431-2432.
11. Picard A. Pot-prescribing doctors warned. The Globe and Mail. http://www.theglobeandmail.com/news/national/ pot-prescribing-doctors-warned/article22506373. Published October 19, 2005. Accessed July 21, 2015.
12. Whiting PF, Wolff RF, Deshpande S, et al. Cannabinoids for medical use: a systematic review and meta-analysis. JAMA. 2015;313(24):2456-2473.
13. Barthwell AG, Baxter LE, Cermak T, et al. The role of the physician in “medical” marijuana: American Society of Addiction Medicine. http://www.aoaam.org/usr/ ASAM_Med_Marijuana_White_Paper_Final.pdf. Published September 2010. Accessed July 11, 2015.
14. Ramaekers JG, Berghaus G, van Laar M, et al. Dose related risk of motor vehicle crashes after cannabis use. Drug Alcohol Depend. 2004;73(2):109-119.
15. Hartman RL, Huestis MA. Cannabis effects on driving skills. Clin Chem. 2013;59(3):478-492.
16. Kondrad E, Reid A. Colorado family physicians’ attitudes toward medical marijuana. J Am Board Fam Med. 2013;26(1):52-60.
17. Hall W. What has research over the past two decades revealed about the adverse health effects of recreational cannabis use? Addiction. 2015;110(1):19-35.
18. Huang YH, Zhang ZF, Tashkin DP, et al. An epidemiologic review of marijuana and cancer: an update. Cancer Epidemiol Biomarkers Prev. 2015;24(1):15-31.
19. Delforterie MJ, Lynskey MT, Huizink AC, et al. The relationship between cannabis involvement and suicidal thoughts and behaviors. Drug Alcohol Depend. 2015;150:98-104.
20. Radhakrishnan R, Wilkinson ST, D’Souza DC. Gone to pot-a review of the association between cannabis and psychosis. Front Psychiatry. 2014;5:54.
21. Masten SV, Guenzburger GV. Changes in driver cannabinoid prevalence in 12 U.S. states after implementing medical marijuana laws. J Safety Res. 2014;50:35-52.
22. Pollini RA, Romano E, Johnson MB, et al. The impact of marijuana decriminalization on California drivers. Drug Alcohol Depend. 2015;150:135-140.
23. Salomonsen-Sautel S, Min SJ, Sakai JT, et al. Trends in fatal motor vehicle crashes before and after marijuana commercialization in Colorado. Drug Alcohol Depend. 2014;140:137-144.
24. Urfer S, Morton J, Beall V, et al. Analysis of Δ9- tetrahydrocannabinol driving under the influence of drug cases in Colorado from January 2011 to February 2014. J Anal Toxicol. 2014;38(8):575-581.
25. Couper FJ, Peterson BL. The prevalence of marijuana in suspected impaired driving cases in Washington state. J Anal Toxicol. 2014;38(8):569-574.
26. Drummer OH, Gerostamoulos J, Batziris H, et al. The involvement of drugs in drivers of motor vehicles killed in Australian road traffic crashes. Accid Anal Prev. 2004;36(2):239-248.
27. Ashton CH. Pharmacology and effects of cannabis: a brief review. Br J Psychiatry. 2001;178:101-106.
28. Schwitzer T, Schwan R, Angioi-Duprez K, et al. The cannabinoid system and visual processing: a review on experimental findings and clinical presumptions. Eur Neuropsychopharmacol. 2015;25(1):100-112.
29. Neavyn MJ, Blohm E, Babu KM, et al. Medical marijuana and driving: a review. J Med Toxicol. 2014;10(3):269-279.
30. Bosker WM, Karschner EL, Lee D, et al. Sustained abstinence improves psychomotor function in chronic daily cannabis smokers. Paper presented at: SOFT 2012: Society of Forensic Toxicologists 2012 Annual Meeting; July 1-6, 2012; Boston, MA.
31. Fabritius M, Augsburger M, Chtioui H, et al. Fitness to drive and cannabis: validation of two blood THCCOOH thresholds to distinguish occasional users from heavy users. Forensic Sci Int. 2014;242:1-8.
32. Annas GJ. Doctors, drugs, and driving—tort liability for patient-caused accidents. New Engl J Med. 2008;359(5):521-525.
33. Coombes v Florio, 877 NE2d 567 (Mass 2007).
34. McKenzie v Hawaii Permanente Medical Group, Inc. 47 P3d 209 (Haw 2002).
35. Ilgen MA, Bohnert K, Kleinberg F, et al. Characteristics of adults seeking medical marijuana certification. Drug Alcohol Depend. 2013;132(3):654-659.
36. Osborne v United States, 166 F Supp 2d 479 (SDW Va 2001).
37. Conrad-Hutsell v Colturi, 2002 Ohio App. LEXIS 2740 (2002).
38. Edersheim JG, Stern TA. Liability associated with prescribing medications. Prim Care Companion J Clin Psychiatry. 2009;11(3):115-119.