Marijuana: Present Landscape

In recent years there have been a lot of changes in both the regulations related to, and the acceptance of Marijuana and CBD products. In the United States, it has become legal for medicinal purposes in 33 states, and for recreational purposes in 10 states. These numbers are changing all the time. It’s a topic having an impact across many industries, and clinical research is no different. Without any real guidance, how does one navigate the common questions?

One of the common questions in clinical research forums:

Is Marijuana considered a concomitant medication in a trial?

Yes, an emphatic and resounding yes. While there are multiple definitions, Concomitant Medications are considered to be prescription and over-the-counter drugs and supplements a study participant has taken along with the study intervention. Marijuana is currently approved, as a medicinal product, in the US to treat certain indications. You can see the press release from the FDA here. Whether or not the individual is taking it for indications approved or being studied is irrelevant. To not consider it a concomitant medication would be medically irresponsible, and introduces a level of risk that is unnecessary.

Should it be exclusionary in your clinical protocol?

Maybe. In general, less variation in the population in a trial is always a good thing for data integrity.

The current clinical climate generally makes marijuana use assumed exclusionary except in rare circumstances. But many times the protocol may not address it at all. It would have to fall into the vague discretion of the Principal Investigator. There are possible impacts from its use in a trial, one of the largest being the potential to mask adverse events. The patient must always come first, and in cases where Marijuana provides a benefit to the patient that is not able to be found in another, more well studied way, the option must be there. The risk is that Marijuana is not as well studied as other treatments.

The exact dosage is difficult to measure (in forms usually consumed), and different strains can contain different levels of substances. The most important factor is to ensure if it’s being used, that it is accurately recorded. Once established that it is clearly a concomitant medication, it is much easier to understand that its use needs to be well justified, in the best interest of the patient, and have reasonable certainty that it will not put the trial at risk.

Other questions to consider:

  1. How could the strain, strength and dosage used be accurately tracked, given the difficulty of measurement (in forms usually consumed), and the difference in potency among strains? There has been a trend in rising potency, see here. And equally important, who is responsible for ensuring the accuracy of this data?
  2. For studies involving questionnaires, such as neurological disorder studies, there would be potential for inconsistency in answers depending on the state of the individual if Marijuana is allowed. How can the individuals state of mind be accurately evaluated?
  3. Masking of AE’s. The challenge is that Marijuana is sometimes used preventatively. Are there potential side effects of the treatment that could be masked by Marijuana use? See here for some of Marijuana’s effects.
  4. The ingredients in Marijuana are currently being tested globally, with one drug just approved by the FDA. How will the industry keep up with a potentially changing drug characterization, all variable based on strain and dosage?
  5. What about individuals who use medicinally with no confirmed diagnosis? If used in a recreational capacity, but is actually self-medicating, how will those instances be handled?

See the attached White Paper for some tips on accurately reporting Marijuana as a concomitant medication.