Cannabis abuse and dependence in kidney transplant candidates

Cannabis use is associated with reduced access to kidney transplantation and an increased risk of acute rejection post-transplant

BACKGROUND

The association between cannabis use and access to waitlisting, transplantation, and post-transplant outcomes remains uncertain.

METHODS

Patients referred for kidney transplant (KT) to the University Health Network from January 1, 2003, to June 30, 2020, and followed until December 31, 2020, were included. Predictors of reported cannabis use were examined using a logistic regression model. The association between cannabis use and time to clearance for KT, undergoing KT, and post-transplant outcomes was evaluated using Cox proportional hazards models.

RESULTS

Among 3734 patients, the prevalence of reported cannabis use was 11.8%. Cannabis use was associated with a lower likelihood of KT clearance (adjusted hazard ratio [aHR] .82 [95% confidence interval (CI): .72, .94]). Once cleared for KT, cannabis use did not predict the subsequent receipt of KT (aHR .92, [95% CI: .79, 1.08]). Among 2091 KT recipients, cannabis use was associated with a higher likelihood of biopsy-proven acute rejection (aHR 1.55, [95% CI: 1.06, 2.27]). The relative hazard of death-censored graft failure was similarly elevated (aHR 1.60 [95% CI: .95, 2.72]). Cannabis use did not predict total graft failure (aHR 1.33 [95% CI: .90, 1.96]), death with graft function (aHR 1.06 [95% CI: .59, 1.89]), or hospital readmission in the first-year post-transplant (aHR 1.26 [95% CI: .95, 1.68]).

CONCLUSIONS

Cannabis users have less access to transplantation and an increased risk of acute rejection, possibly leading to more graft loss. Further studies are warranted to understand possible mechanisms for the increased risk of allograft immune injury among cannabis users.

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.

The Combined Roles of Race/Ethnicity and Substance Use in Predicting Likelihood of Kidney Transplantation

BACKGROUND

Racial/ethnic minorities face known disparities in likelihood of kidney transplantation. These disparities may be exacerbated when coupled with ongoing substance use, a factor also reducing likelihood of transplantation. We examined whether race/ethnicity in combination with ongoing substance use predicted incidence of transplantation.

METHODS

Patients were enrolled between March 2010 and October 2012 at the time of transplant evaluation. Substance use data were retrieved from transplant evaluations. Following descriptive analyses, the primary multivariable analyses evaluated whether, relative to the referent group (White patients with no substance use), racial/ethnic minority patients using any substances at the time of evaluation were less likely to receive transplants by the end of study follow-up (August 2020).

RESULTS

Among 1152 patients, 69% were non-Hispanic White, 23% non-Hispanic Black, and 8% Other racial/ethnic minorities. White, Black, and Other patients differed in percentages of current tobacco smoking (15%, 26%, and 18%, respectively; P = 0.002) and illicit substance use (3%, 8%, and 9%; P < 0.001) but not heavy alcohol consumption (2%, 4%, and 1%; P = 0.346). Black and Other minority patients using substances were each less likely to receive transplants than the referent group (hazard ratios ≤0.45, P ≤ 0.021). Neither White patients using substances nor racial/ethnic minority nonusers differed from the referent group in transplant rates. Additional analyses indicated that these effects reflected differences in waitlisting rates; once waitlisted, study groups did not differ in transplant rates.

CONCLUSIONS

The combination of minority race/ethnicity and substance use may lead to unique disparities in likelihood of transplantation. To facilitate equity, strategies should be considered to remove any barriers to referral for and receipt of substance use care in racial/ethnic minorities.

Substance use among adolescents and young adults with chronic kidney disease or kidney failure

Substance use, a significant public health issue, is well described in the adult chronic kidney disease (CKD) population. Knowledge about substance use in the adolescent and young adult (AYA) CKD population such as prevalence, impact on kidney function, medication adherence, and psychosocial well-being remain largely unknown. Awareness of and inquiring about substance use is paramount to providing evidence-based care and preparation to transition to adult-focused health services. The authors in this review identify commonly used substances (alcohol, tobacco, marijuana, etc.) and how they impact kidney function and care of the AYA with CKD or kidney failure. Recommendations for screening and intervention strategies are provided.

Canadian Society of Transplantation White Paper: Ethical and Legal Considerations for Alcohol and Cannabis Use in Solid Organ Listing and Allocation

Alcohol and cannabis use as a contraindication to organ transplantation is a controversial issue. Until recently, patients in Canada with alcohol-associated liver disease were required to demonstrate abstinence for 6 mo to receive a liver transplant. There is no equivalent rule that is applied consistently for cannabis use. There is some evidence that alcohol and cannabis use disorder pretransplant could be associated with worse outcomes posttransplantation. However, early liver transplantation for patients with alcohol-associated liver disease in France and in the United States has led to challenges of the 6-mo abstinence rule in Canada in the media. It has also resulted in several legal challenges arguing that the rule violates human rights laws regarding discrimination in the provision of medical services and that the rule is also unconstitutional (this challenge is still before the court). Recent legalization of cannabis use for adults in Canada has led to questions about the appropriateness of limiting transplant access based on cannabis use. The ethics committee of the Canadian Society of Transplantation was asked to provide an ethical analysis of cannabis and alcohol abstinence policies. Our conclusions were as follows: neither cannabis use nor the 6-mo abstinence rule for alcohol use should be an absolute contraindication to transplantation, and transplant could be offered to selected patients, further research should be conducted to ensure evidence-based policies; and the transplant community has a duty not to perpetuate stigma associated with alcohol and cannabis use disorders.

Epidemiology of cannabis use and associated outcomes among kidney transplant recipients: A meta-analysis

OBJECTIVE

Cannabis is the most commonly used recreational drug in the United States, and transplant acceptability for cannabis using candidates varies among transplant centers. However, the prevalence and impact of cannabis use on outcomes of kidney transplant recipients remain unclear. This study aimed to summarize the prevalence and impact of cannabis use on outcomes after kidney transplantation.

METHODS

A literature search was performed using Ovid MEDLINE, EMBASE, and The Cochrane Library Databases from inception until September 2019 to identify studies assessing the prevalence of cannabis use among kidney transplant recipients, and reported adverse outcomes after kidney transplantation. Effect estimates from the individual studies were obtained and combined utilizing random-effects, generic inverse variance method of DerSimonian-Laird.

RESULTS

A total of four cohort studies with a total of 55 897 kidney transplant recipients were enrolled. Overall, the pooled estimated prevalence of cannabis use was 3.2% (95% CI 0.4%-20.5%). While the use of cannabis was not significantly associated with all-cause allograft failure (OR = 1.31, 95% CI 0.70-2.46) or mortality (OR = 1.52, 95% CI 0.59-3.92), the use of cannabis among kidney transplant recipients was significantly associated with increased death-censored graft failure with pooled OR of 1.72 (95% CI 1.13-2.60).

CONCLUSIONS

The overall estimated prevalence of cannabis use among kidney transplant recipients is 3.2%. The use of cannabis is associated with increased death-censored graft failure, but not mortality after kidney transplantation.

The growing dilemma of legalized cannabis and heart transplantation

This in-depth review discusses cannabis as it relates to heart transplantation and the growing dilemma of legalization around the world creating disparities in transplant candidacy. One will learn about two of the most common cannabinoids: Δ⁹-tetrahydrocannabinol (THC) and cannabidiol (CBD). These cannabinoids are metabolized by cytochrome P-450 and P glycoprotein, which are essential for the metabolism of drugs for transplantation, such as calcineurin inhibitors. Addiction, withdrawal, and cannabis use disorder will be reviewed as well as hyperemesis syndrome. Maintaining adequate immunosuppression will depend on a variety of factors, including drug-drug interactions, pharmacokinetics of cannabinoids and chronicity of cannabis usage. These drug interactions are further confounded by varying concentrations of cannabis products available at medical dispensaries. One will also learn about the outcomes of transplant recipients using cannabis such as graft failure and the risk of infections. Although more research is needed to establish transplant guidelines, the available data is concerning and fairness in organ distribution should not vary by transplant program or institution.

The Clinical Conundrum of Cannabis: Current Practices and Recommendations for Transplant Clinicians: An Opinion of the Immunology/Transplantation PRN of the American College of Clinical Pharmacy

Cannabis, or marijuana, comprises many compounds with varying effects. It has become a treatment option for chronic diseases and debilitating symptoms, and evidence suggests that it has immunomodulatory and antiinflammatory properties. Transplant centers are more frequently facing issues about cannabis, as indications and legalization expand. As of February 2020, 33 states and the District of Columbia have legalized medical cannabis, and 14 have legalized recreational cannabis. Moreover, 8 states have passed legislation prohibiting the denial of transplant listing solely based on cannabis use. Studies demonstrate the potential for significant pharmacokinetic and pharmacodynamic interactions between cannabis and immunosuppression. Additionally, safety concerns include increased risk of myocardial infarction, ischemic stroke, tachyarrhythmias, malignancy, neurocognitive deficits, psychosis, other neuropsychiatric disorders, cannabis use disorder, respiratory symptoms, and infection. A recent retrospective database study found a negative association between documented cannabis use disorder and graft survival, but little additional evidence exists evaluating this relationship. In the absence of robust clinical data, transplant centers need a clear, reasoned, and systematic approach to cannabis. The results of our national survey, unfortunately, found little consensus among institutions. As both recreational and medicinal cannabis become more ubiquitous nationwide, transplant centers will need to develop comprehensive policies to address its use.

Cannabis use and bariatric surgery psychology practice: survey and insights

BACKGROUND

Cannabis is second only to alcohol as a substance of abuse and dependence in the United States. While there is extensive research examining alcohol use and bariatric surgery, there is currently little research and there are no published guidelines specific to cannabis use and bariatric surgery.

OBJECTIVES

To identify major themes and general guidelines applied by bariatric surgery psychology clinicians.

SETTING

This practice survey was disseminated to bariatric surgery psychologists at various U.S. academic medical centers, hospitals, and private practices.

METHODS

An electronic, 35-question survey was sent to 47 bariatric surgery psychologists to collect information on current clinical practice guidelines regarding cannabis use before and after bariatric surgery.

RESULTS

The survey questionnaire was completed by 34 (72.34%) bariatric surgery psychologists. The major identified themes included: (1) the lack of a standardized assessment of cannabis use; (2) a requirement for 3 months of abstinence from cannabis before bariatric surgery; (3) recommended lifetime abstinence from cannabis after bariatric surgery; and (4) discussion of cannabis use risks following bariatric surgery, including appetite stimulation, addiction potential, and possible negative impacts on judgment.

CONCLUSION

Cannabis use will likely further increase in the United States. This survey highlighted common bariatric surgery psychology practices in the absence of extensive research and published guidelines. These findings suggest a preliminary framework with which to address cannabis use in patients seeking bariatric surgery. It is recommended that professional organizations and societies build on these initial survey findings to develop guidelines for more consistent, evidence-based practice regarding cannabis use and bariatric surgery.

A Review of the Prevalence of Illicit Substance Use in Solid-Organ Transplant Candidates and the Effects of Illicit Substance Use on Solid-Organ Transplant Treatment Outcomes

Solid-organ transplantation is one of the significant advances in the medical field that have improved the quality of life and survival rates of numerous patients with end-organ dysfunction. Substance use is a common condition of individuals who are in need of solid-organ transplantation. The implications of substance use on solid-organ transplants are gaining increasing attention over the past decade. The current review seeks to explore the prevalence rate of illicit substance use among those who receive solid-organ transplantation (pre and post-transplant) and whether illicit substance use before solid-organ transplantation affects the outcome of solid-organ transplants. We searched the Medline database for all the articles available in English on the prevalence of substance use in the context of solid-organ transplant and the effect on outcome measures. We found 21 relevant articles. It appears that substance use is fairly common among solid-organ transplant candidates, with cannabis being the most common substance of abuse. A heterogeneous sample precludes the drawing of a clear-cut conclusion. But it appears that substance use may affect various outcomes of solid-organ transplants. The existing literature may not be sufficient to adequately assess the risk but limited evidence indicates that illicit substance use, particularly cannabis use, may not affect the overall survival following a solid-organ transplant.

The nephrologist's guide to cannabis and cannabinoids

PURPOSE OF REVIEW

Cannabis (marijuana, weed, pot, ganja, Mary Jane) is the most commonly used federally illicit drug in the United States. The present review provides an overview of cannabis and cannabinoids with relevance to the practice of nephrology so that clinicians can best take care of patients.

RECENT FINDINGS

Cannabis may have medicinal benefits for treating symptoms of advanced chronic kidney disease (CKD) and end-stage renal disease including as a pain adjuvant potentially reducing the need for opioids. Cannabis does not seem to affect kidney function in healthy individuals. However, renal function should be closely monitored in those with CKD, the lowest effective dose should be used, and smoking should be avoided. Cannabis use may delay transplant candidate listing or contribute to ineligibility. Cannabidiol (CBD) has recently exploded in popularity. Although generally well tolerated, safe without significant side effects, and effective for a variety of neurological and psychiatric conditions, consumers have easy access to a wide range of unregulated CBD products, some with inaccurate labeling and false health claims. Importantly, CBD may raise tacrolimus levels.

SUMMARY

Patients and healthcare professionals have little guidance or evidence regarding the impact of cannabis use on people with kidney disease. This knowledge gap will remain as long as federal regulations remain prohibitively restrictive towards prospective research.