Before you recommend medical marijuana…
Although medical marijuana is not actually “prescribed,” there are steps to take before recommending or facilitating its use for a particular patient (TABLE 2).25-29
After ensuring that he or she has a condition for which there is evidence to support it, you need to do a risk evaluation, drawing on the opioid-prescribing paradigm to look for contraindications to the use of a controlled substance or factors that indicate the need for additional precaution (TABLE 3).10,25,26
Take a thorough medical history and use screening tools
A thorough patient and family medical history, along with principles of Screening, Brief Intervention, and Referral for Treatment (SBIRT), can be used to identify addiction-prone substance use.28 You can also use a validated tool such as the Cannabis Use Disorder Test (CUDIT-R), available at http://sfmi.wufoo.com/forms/qulgngl12rydww/.Body fluid (usually urine) testing is also recommended.30 You may be able to access your state’s Prescription Drug Monitoring Program to check for worrisome prescribing, as well.
Stratify risk
The next step is to determine whether the patient is at low, intermediate, or high risk for use of a controlled substance based on your findings. Patients who are younger than 25 years, for example, have an increased risk.And high-risk patients—those with a history of substance abuse, psychiatric illness, or sexual trauma—are unlikely to be good candidates for medical marijuana10,25,26 and should be informed in a nonjudgmental manner that their problem is better addressed without it.
If the risk/benefit balance is favorable and the patient is willing to give medical marijuana a try, complete a signed certification of a medical condition for which medical marijuana is authorized in your state. Details of state laws are available at medicalmarijuana.procon.org/view.resource.php?resourceID=000881.
Because the individuals who dispense medical marijuana have varying skills, physicians should collaborate with clinicians judged to be knowledgeable about the best strains of marijuana, the best administration route, and the lowest effective dose—typically a pain management specialist or a physician experienced in recommending medical marijuana appropriately. Vaporization of marijuana, for use with an inhalation device, may prevent some of the potentially negative consequences of smoking it.31 Vaporizing is thought to eliminate some of the irritating—and possibly carcinogenic—materials contained in marijuana smoke.
Follow risk mitigation principles
Because marijuana is a controlled substance, you will need to talk to the patient about how to store and, if necessary, dispose of it to avoid the risk of diversion—a major concern about the legalization of marijuana.
You can cite a small study of adolescents in substance abuse treatment, in which 3 out of 4 reported having used someone else’s medical marijuana a median of 50 times.32 Adolescents who used medical marijuana had an earlier age of regular marijuana use, more marijuana abuse, and more dependence and conduct disorder symptoms compared with teens who had not used medical marijuana.32
It is important, too, to obtain informed consent and draw up a controlled substance agreement, signed by the patient and you. The agreement should outline expected patient behavior, including regular monitoring and body fluid testing, and the consequences of a lack of adherence. (Using a certified laboratory for drug testing is important, as it avoids the possibility of actions based on inaccurate in-office screening.33) Regular follow-up also provides an opportunity to assess symptom and functional improvement.
If the patient fails to keep appointments and does not respond to efforts to address the problem, the marijuana recommendation may have to be rescinded. Adverse effects, continued aberrant behavior, or evidence of cannabis use disorder may necessitate immediate cessation of the drug. Depending on the scope of the problem, collaboration with addiction therapy may be necessary. Discharge from the practice, of course, should be the last resort.
CASE › At a subsequent visit—after a trial with the maximal dose of dronabinol—Ms. B states that although she had some relief, she continues to have a high degree of breakthrough pain. You suspect that medical marijuana may do more to alleviate her pain, and establish a regimen to quickly taper her off dronabinol.
You consult with a pain management specialist, who suggests that the patient begin with raw marijuana with a 10% THC content, smoking 0.6 gm tid. You obtain informed consent and ask her to sign a controlled substance agreement, explaining that you will need to monitor her closely for dizziness, dysphoria, and hallucinations, among other adverse effects. You instruct her not to drive for 6 hours after smoking marijuana, and you schedule a follow-up appointment in 2 weeks.
Before she leaves, Ms. B receives a copy of your clinic note and written recommendation that she can take to the state dispensary. The note indicates that she will use marijuana for neuropathic pain.