The impact of the use of cannabis in the treatment of liver disease is still unknown; however, some information has come to light on its impact on patient’s chances of receiving a liver transplant. Although some potential benefits have been hypothesized for the use of the marijuana-derived product in pain reduction, some states in the United States will remove transplant candidates form the list if they use the product.
In an effort to help unpack the rules and regulations, as well as the potential risk and benefits of cannabis use for patients with liver disease, Norah Terrault, MPH, MD, director of the Viral Hepatitis Center at University of California, San Francisco, spoke with MD Magazine® at the 2018 American Association for the Study of Liver Diseases (AASLD) Liver Meeting, November 9-13, 2018, in San Francisco, California.
[Editor’s note: Transcript is slightly modified for readability.]
MD Magazine®: How does the use of cannabis affect a patient’s status on the liver transplant list?
Terrault: There is some rational in the transplant setting that a patient cannot use marijuana and stay on the list. [We decided this in our program and] our rational was based on very real concerns.
[First,] we were concerned that posttransplant we did not know if there was going to be any effect or interaction between the marijuana products and the immunosuppressant drugs. The goal with transplant patients is to ensure that we have long-term graft survival and patient survival, and so we did not want to have any potential for the marijuana to interact or cause changes in the metabolism of drugs that might affect immunosuppressive levels.
There are some data that show that depending on the product—because it’s not one thing, marijuana, there’s many different components—[there could be different effects]. We were concerned that there could be potentially some drug-drug interactions—probably not major, but potentially modest. We do not want to have any potential issue with the patient’s immunosuppressive levels and their risk for rejection. That was 1 reason.
[Second,] many people smoke marijuana products. There are very old data—but I think [it] is still relevant today—[that showed] some of the marijuana products were contaminated by molds because they’re grown in the earth, and [molds] exist in nature (these are natural products). Some of those molds like Aspergillus are very serious and can be lethal infections in someone who is immunocompromised.
I think we still have very strong feelings that we would like our transplant patients not to use these products because we think there are some potentially unknown risks. There may be some real consequences to the use of these products, especially if they are smoked. Not to mention that there are some good data about the risk for lung disease and [marijuana] as an activation of asthma, etc.
For those reasons, we really feel there are some health risks, and we counsel against it. We advise patients, posttransplant, to avoid use of marijuana because of those concerns.
There is [also] the legal issue of the policies of the program for getting on the list, but there are some real concerns on the part of clinicians who take care of transplant patients about the potential risks to the patient because they are immunocompromised, and/or the interactions with medications that would compromise the graft.
We advise individuals posttransplant to not be using.
The truth is that, in the future, I think there are going to be recognized health benefits of cannabinoid products. There are some interesting data about how it can be used to treat chronic pain, and I think that is a particularly that I’m interested in, given our concerns about the escalating use of narcotics, the potential for dependency on opioids, opioid addiction, and consequences of that, and so I think if we can find potentially safer alternatives where there is not an overdose risk or where there is less potential for side effects, I’m all for that.
There is a very nice report, coming back to the transplant patients, where they had a patient who was on narcotics at a fairly high dose, and they were having difficulty managing the patient’s pain. [When] they used CBD products, the patient was able to come off all the narcotics and have very good pain control. In that case, it was really a benefit to the patient and to the provider that they had an alternative to use of narcotics.
I think it’s an area in which we’re really still learning, and as more of these [products] become available and more studies are completed, I think we will find that there is a place where the benefits certainly outweigh risks. But, we are still in early days for the point of understanding that. I see, in particular the area of pain management, where this might be an alternative that we’d be happy to support because it would be safer than some of the other options that we currently have.