Cannabinoid Use Among Liver Transplant Recipients

Cannabis use in liver transplant candidates and recipients

The increasing legality and acceptance of cannabis sale and consumption across the United States has led to a measurable increase in cannabis use nationwide, including in liver transplant (LT) candidates and recipients. With over 75% of liver transplant recipients transplanted in states with legalized use of medicinal and/or recreational cannabis, liver transplant clinicians must have expertise in the assessment of cannabis use given its potential impact on clinical care. In this review, the authors provide an understanding of nomenclature and tools to assess cannabis use, highlight essential components to guide clinical policy development and implementation, and discuss the potential impacts of cannabis use on patients' transplant course.

Cannabidiol's impact on drug-metabolization

IMPORTANCE

Products containing cannabidiol(CBD) are easily accessible. CBD is reported to inhibit the drug-metabolizing proteins(DMP) Cytochrome P450(CYP)3A4/5, CYP2C9, CYP2B6, CYP2D6, CYP2E1, CYP1A2, CYP2C19, carboxylesterase 1(CES1), uridine 5'diphospho-glucoronosyltransferase(UGT)1A9, UGT2B7, P-glycoprotein(P-gp) and Breast Cancer Resistance Protein(BCRP). The relevance of CBD-drug interactions is largely unknown. Aim of the study was to identify drugs, potentially interacting with orally ingested CBD, to assess whether CBD-drug interactions have been reported, and if substrates of DMP are frequently prescribed drugs.

OBSERVATIONS

Identified were 403 drugs as substrates of DMP. CBD-drug interactions were reported for 53/403 substrates in humans (n = 25), in vivo (n = 13) or in vitro (n = 15). In 31/53 substrates, CBD induced an increase, in 1/53 a decrease, in 4/53 no change in the substrate level. For 5/53 substrates, the results were controversial, and in 12/53 no substrate levels were reported. Among the 30 most frequently prescribed drugs in Germany were 67% substrates of DMP and among the 50 most frequently prescribed drugs in the USA 68%.

RELEVANCE AND CONCLUSIONS

There is an urgent need for pharmacologic studies on CBD-drug interactions. Patients should be educated on the potential risk and awareness should be increased among physicians. Regulatory authorities should become aware of the problem and start an initiative on an international level to increase the safety of CBD.

Review of liver transplantation candidacy and outcomes among patients who use cannabis: Is it time for a change in policy?

Background

Recreational cannabis was legalized in Canada in 2018. A controversial contraindication for liver transplantation is cannabis. There is currently no consensus regarding cannabis use in liver transplant candidates. We aim to investigate liver transplantation candidacy and outcomes among cannabis users.

Methods

English peer-reviewed studies on PubMed and Google Scholar were searched on September 9, 2022, using keywords including "cannabis," "liver transplantation," and their synonyms. Titles and abstracts were screened, followed by full texts. Reference lists were reviewed. Studies that investigated liver transplantation candidacy and outcomes among cannabis users were included.

Results

The proportion of patients listed for liver transplantation was significantly less among cannabis users than among non-users. Time to listing was longer for cannabis users than non-users. The incidence of delisting was similar. There is an inconsistency between transplant centres regarding transplantation candidacy for cannabis users. While only 14% of Canadian centres had a policy in place and preferred candidates to abstain or decrease cannabis use before transplantation, a third of Canadian centres rejected cannabis users. Observational studies failed to demonstrate significant differences in patient survival between pre-transplantation cannabis users and non-users. However, self-reported mental health ratings were worse in post-transplantation cannabis users than in non-users and former users.

Conclusions

Current observational data do not support a link between cannabis use and poor patient survival post-transplantation. However, high-quality prospective studies are needed to better elucidate the impact of cannabis use on liver transplantation outcomes. Liver transplant candidacy should be evaluated through a multidisciplinary and comprehensive approach considering all relevant psychosocial factors.

Marijuana use and post-transplant complications and non-compliance in liver transplant patients

BACKGROUND

Liver transplant (LT) is a lifesaving treatment for patients with end stage liver disease. Historically, institutions across the United States have deemed active marijuana use as an exclusion criterion for listing. This study aims to investigate LT outcomes in patients with history of marijuana use prior to LT.

METHODS

We performed a retrospective review of 111 patients who tested positive for marijuana on urine drug screen during initial LT evaluation between February 2016 and January 2021. 100 non-marijuana users who underwent LT were cross matched for control. Patient demographics, substance use history, and transplant decisions were recorded. Post-LT variables were also collected up to 1 year post surgery including postoperative infections, issues with non-compliance, and continued substance use. Chi-square analysis was used to assess the association between pre-transplant marijuana use and post-transplant complications. Logistics regression was implemented to measure associations amongst the entire cohort.

RESULTS

From 111 marijuana users, 32 (29%) received a transplant. There was no statistical difference in post-LT outcomes between marijuana and non-marijuana users, including incidence of cardiac, respiratory, renal, psychiatric, or neurological complications, as well as readmission rates post-surgery. There were no statistically significant associations between marijuana use with post-transplant bacterial or fungal infections, medication non-compliance, or continued substance use (all p>0.05). Marijuana use was associated with pre-LT tobacco use (p = 0.020).

CONCLUSIONS

Our data indicates that marijuana is not associated with increased risk of postoperative noncompliance, other organ complications, infections, or death. As a single factor, marijuana may not need to be a contraindication for LT.

Substance use disorders in organ transplantation: perennial challenges and interprofessional opportunities

PURPOSE OF REVIEW

The current article examines recent publications regarding ongoing clinical and ethical challenges and opportunities related to substance use disorders (SUD) in solid organ transplantation (SOT) utilizing a lens of interprofessional clinical models and care delivery.

RECENT FINDINGS

Innovative interprofessional clinician skillsets and care models are increasingly emphasized in the SOT literature as the standard of care for common, complex psychosocial problems like substance use and SUD. Cannabinoids are common among candidates and recipients and present several unique quandaries to SOT teams. Opioid use disorder treatment can often be definitively treated with medications that SOT teams may find unfamiliar, controversial, or aversive. Arguably the quintessential example of SUD in SOT, early liver transplantation for patients with alcohol-related liver disease and short periods of sobriety has become increasingly common and accepted in recent years requiring liver teams to rapidly acquire significant interprofessional psychiatric awareness and expertise. The question of retransplantation in patients who have experienced recurrent SUD remains unsettled.

SUMMARY

Regardless of substances used or organs transplanted, interprofessional care continues to emerge as a foundational aspect of clinical care and research in SOT.

Cannabinoids and solid organ transplantation: Psychiatric perspectives and recommendations

Cannabinoid use in patients seeking solid organ transplantation (SOT) is an important and unsettled matter which all transplantation clinicians regularly encounter. It is also a multifaceted, interprofessional issue, difficult for any specialty alone to adequately address in a research article or during clinical care. Such uncertainty lends itself to bias for or against cannabinoid use accompanied by inconsistent policies and procedures. Scientific literature in SOT regarding cannabinoids often narrowly examines the issue and exists mostly in liver and kidney transplantation. Published recommendations from professional societies are mosaics of vagueness and specificity mirroring the ongoing dilemma. The cannabinoid information SOT clinicians need for clinical care may require data and perspectives from diverse medical literature which are rarely synthesized. SOT teams may not be adequately staffed or trained to address various neuropsychiatric cannabinoid effects and risks in patients. In this article, authors from US transplantation centers conduct a systematized review of the few existing studies regarding clinician perceptions, use rates, and clinical impact of cannabinoid use in SOT patients; collate representative professional society guidance on the topic; draw from diverse medical literature bases to detail facets of cannabinoid use in psychiatry and addiction pertinent to all transplantation clinicians; provide basic clinical and policy recommendations; and indicate areas of future study.

Integrated Care of Alcohol-Related Liver Disease

BACKGROUND/AIMS

Alcohol-related liver disease (ALD) is the medical manifestation of alcohol use disorder, a prevalent psychiatric condition. Acute and chronic manifestations of ALD have risen in recent years especially in young people and ALD is now a leading indication of liver transplantation (LT) worldwide. Such alarming trends raise urgent and unanswered questions about how medical and psychiatric care can be sustainably integrated to better manage ALD patients before and after LT.

METHODS

Critical evaluation of the interprofessional implications of broad and multifaceted ALD pathophysiology, general principles of and barriers to interprofessional teamwork and care integration, and measures that clinicians and institutions can implement for improved and integrated ALD care.

RESULTS

The breadth of ALD pathophysiology, and its numerous medical and psychiatric comorbidities, ensures that no single medical or psychiatric discipline is adequately trained and equipped to manage the disease alone.

CONCLUSIONS

Early models of feasible ALD care integration have emerged in recent years but much more work is needed to develop and study them. The future of ALD care is an integrated approach led jointly by interprofessional medical and psychiatric clinicians.