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15 Articles in Volume 19, Issue #3
Analgesics of the Future: The Potential of the Endocannabinoid System
Buprenorphine: A Promising Yet Overlooked Tool
Chronic Pain and the Psychological Stages of Grief
Could a Personalized Approach to Therapy End the War on Pain?
Finally, A Systematic Classification of Pain (the ICD-11)
Hormone Therapy for Chronic Pain
How to Communicate with a Medical Marijuana Dispensary
Letters: Opioid Conversions; Scrambler Therapy for CRPS
MSK Pain: Time for an Enhanced Assessment Model
National Drug Use & Abuse Trends: Prescribed and Illicit
Neuroplasticity and the Potential to Change Pain Response
Should Emergency Naloxone Be in Schools?
Talking to Patients about Medical Cannabis
Utility of Pulsed Radiofrequency Ablation in Xiphodynia
When Opioid Prescriptions Are Denied

How to Communicate with a Medical Marijuana Dispensary

Ask the Expert: If I recommend marijuana, what should I ask the dispensary?
Pages 65-67

Due to US DEA classification of marijuana as a Schedule I drug, meaning there is no accepted medical use and a high potential for abuse, healthcare providers have not been adequately educated about its use. No clinical guidelines exist to guide dosing or indications for use, making it difficult to have a standardized treatment approach, especially with differing state regulations.

Instead of traditional pharmacies, patients seeking marijuana for medicinal use often go to dispensaries. Some dispensaries focus on stocking and selling only recreational products or medicinal products, while others offer both. Therefore, products and the role of staff may vary significantly—from online-certified “budtenders” to licensed pharmacists—making it difficult for providers to effectively communicate and collaborate with the dispensary team. In addition, not all dispensary teams are making evidence- based recommendations, so it is important to inquire about proper training before referring patients to a specific dispensary.1 Ask the dispensary: Do they offer medicinal products, recreational products, or a combination?

Communicating with your local medical marijuana dispensary can help address key questions and concerns before prescribing cannabis for your patients. (Source: 123RF)

Species and Strains

Marijuana, known as the genus Cannabis, is divided into three species: Cannabis sativa, Cannabis indica, and Cannabis ruderalis. The major cannabinoids present in Cannabis are delta9-tetrahydrocannabinol (THC) and cannabidiol (CBD). Cannabis ruderalis is rarely grown alone due to low levels of THC. Hybridization occurs by breeding different species, to create new strains with select characteristics.2

Numerous strains of marijuana exist, so understanding composition is important, instead of relying on names alone. Strains may contain C. indica, C. sativa, or varying amounts of either. Strains are also designed to contain varying ratios of THC, CBD, and other cannabinoids and compounds. C. sativa is described as energizing, uplifting, and better for day-time use. C. indica is described as calming, sedating, and better for night-time use. THC induces the psychoactive effects of marijuana, while CBD lacks psychoactivity.3 These characteristics are important to consider when recommending therapy. Dispensary staff should be able to provide these details for each of their products.1 Ask the dispensary: What is the ratio of THC:CBD in the products you are recommending for your patient(s)?

Route of Administration

Smoking is a common route of administration of marijuana, but is not recommended due to potential toxicity and respiratory symptoms. Vaporization is another option that is considered to have less harmful byproducts and less respiratory symptoms. Smoking and vaporization allow for rapid action and may be advantageous for acute or episodic symptoms.

Oral marijuana products include oils, capsules, edibles, oromucosal sprays, tinctures, and lozenges. These products have a longer duration of action and may be advantageous for chronic symptoms. Difficulty in dosing and titration along with limited research has deterred the use of some of these oral formulations, including edibles, tinctures, and lozenges. Topical products and suppositories are other available dosage forms with limited research.4 See Table II for further detail. Ask the dispensary: Which dosage forms are available at their location?


Dosing medical marijuana is a complex responsibility and should be individualized for each patient. A general approach to initiating therapy is “start low, go slow, and stay low,” which may reduce THC-mediated side effects. Using strains with lower THC and higher CBD may help to negate any side effects. Doses of marijuana are dependent upon the dosage form. Most patients use 1 to 3 g/day of herbal marijuana (ground flower buds), with few using more than 5 g/day. Patients inhaling marijuana should start with one inhalation and then increase by one inhalation every 15 to 30 minutes until they achieve symptom control (waiting in between inhalations can help to control for unwanted side effects). Vaporization may be beneficial as an additional therapy for episodic worsening of symptoms, but estimation of dosage is difficult due to influential variables (ie, depth of inhalation, length of holding breath). Long-acting oral preparations (including edibles), dosed in milligrams, are the mainstay of therapy in patients with chronic conditions/symptoms.4

For CBD products, there are no established dosing guidelines for the use of pain. Products with higher CBD concentration may require larger doses, but doses starting at 5 to 20 mg/day have provided benefit in some patients.4 Staff members at dispensaries will be able to provide information regarding available doses of different products.3

Side Effects and Drug-Drug Interactions

THC-mediated side effects are dose-dependent and may include anxiety, cognitive effects, nausea, euphoria, blurred vision, and so forth. To limit side effects, initiate therapy at bedtime. Daytime therapy may require the use of a less sedating strain dosed two to three times daily (see Table III for dosing titration examples). Doses greater than 20 to 30 mg THC equivalent per day may increase the risk of side effects or induce tolerance without improving efficacy.4

Tolerance can be developed to psychoactive effects, without losing medical benefit, so it is important to educate patients that euphoric effects are unnecessary for adequate symptom control. If tolerance becomes a problem, then a drug vacation of 48 hours or longer may be beneficial.4

There is limited data regarding drug-drug interactions of THC and CBD with other medications. We can predict potential drug-drug interactions by assessing metabolism. THC is metabolized by CYP3A4 and CYP2C9, therefore, drugs that inhibit or induce these CYP enzymes would increase or decrease the concentration of THC. CBD is metabolized by CYP3A4 and CYP2C19, therefore, drugs that inhibit or induce these CYP enzymes would increase or decrease the concentration of CBD.5 Ask the dispensary: What side effects have they heard about or witnessed from their clients with regard to the products you may be recommending for your patients?

Know the Facts

All healthcare professionals, including nurses and pharmacists, should be educated on medical marijuana in order to provide reliable information to ensure safety. Several states have an established role for pharmacists in medical marijuana dispensaries. For example, in Connecticut and Minnesota, a pharmacist is required to dispense medical marijuana and is always available to help patients choose a product.

With proper education on the pharmacology and clinical use of marijuana, pharmacists could be better positioned to assist in questions related to its medicinal use. Pharmacists should be able to share with clinicians and patients alike the potential for adverse events and /or drug-drug interactions, directions for safe use, and the importance of continued adherence to other medications.6  As medical marijuana use expands, all providers will need to be aware of the laws in their state and how to effectively communicate about medical marijuana with patients. Ask the dispensary: Do they have an on-staff licensed pharmacist?

Cannabis: Solution or Epidemic?

A Q&A with NIDA Deputy Director Wilson Compton, MD, MPE, reported by Angie Drakulich

Cannabinoids have been referred to as both the next pain solution and the next epidemic. What’s your take?

At the moment, it is unclear if increased access to medical and/ or recreational marijuana will make a meaningful difference in overall rates of opioid addiction or in the effective treatment of pain. There is evidence that cannabis use and cannabis use disorders increase in states with medical marijuana laws. There is also some evidence that inhaled cannabis may be effective for the treatment of chronic pain and moderate evidence that nabiximols (which contain an equal ratio of THC:CBD) may be beneficial for the treatment of chronic neuropathic or cancer pain. The category of “cannabinoids” encompasses many different chemicals. Some, like THC, can lead to addiction. Others do not appear to carry significant addiction risk; one example is cannabidiol, which was approved by the FDA for the treatment of two rare seizure disorders.

Do you foresee cannabinoids as a common line of treatment for chronic pain conditions or pain-related symptoms?

The marijuana plant itself is not considered an ideal medication candidate for the following reasons:

  • It is an unpurified plant containing numerous chemicals that have not been fully characterized.
  • The variability of active components makes it difficult to reproduce a consistent dose.
  • It is often consumed by smoking, potentially contributing to adverse effects on lung health.
  • Its cognitive- and motor-impairing effects may limit utility.

Purified cannabinoid compounds, however, are viable candidates for medication development. As well summarized by a review carried out by NAM, there is variable evidence for the therapeutic effects of cannabinoid compounds. Current evidence shows that cannabinoids have promise for the treatment of some pain conditions and associated insomnia, and that they are not effective for associated depression symptoms.

Looking ahead, what major challenges do cannabinoids pose?

Cannabinoids do not have the respiratory depressant effects that make opioids so deadly. Therefore, an overdose epidemic is highly unlikely to result from cannabis use. Rather, the major challenge posed by cannabinoids is that their medical use has outpaced the evidence base, so possible risks and benefits are not fully appreciated. Yet, they are widely used. As a result, the potential of medical cannabis to result in increased incidence of cannabis use disorder should be carefully monitored. Doctors and patients should always weigh the risks and benefits of any treatment course, including the risk of developing an addiction to opioids or marijuana used to treat pain.

What significant differences lie in these challenges between medical cannabis and recreational cannabis?

Of particular concern to NIDA is the possibility that increased availability of medical and/or recreational cannabis could increase adolescent exposure to cannabis, which can have a detrimental impact on brain development.

See prescribing considerations for cannabis with Drs. Mark A. Ware and David J. Casarett

Last updated on: May 6, 2019
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Talking to Patients about Medical Cannabis
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