Cannabis Dependence or Abuse in Kidney Transplantation: Implications for Posttransplant Outcomes

Abstract

Background. Cannabis is categorized as an illicit drug in most US states, but legalization for medical indications is increasing. Policies and guidance on cannabis use in transplant patients remain controversial. Methods. We examined a database linking national kidney transplant records (n = 52 689) with Medicare claims to identify diagnoses of cannabis dependence or abuse (CDOA) and associations [adjusted hazard ratio (aHR) with 95% upper and lower confidence limits (CLs)] with graft, patient, and other clinical outcomes. Results. CDOA was diagnosed in only 0.5% (n = 254) and 0.3% (n = 163) of kidney transplant recipients in the years before and after transplant, respectively. Patients with pretransplant CDOA were more likely to be 19 to 30 years of age and of black race, and less likely to be obese, college-educated, and employed. After multivariate and propensity adjustment, CDOA in the year before transplant was not associated with death or graft failure in the year after transplant, but was associated with posttransplant psychosocial problems such as alcohol abuse, other drug abuse, noncompliance, schizophrenia, and depression. Furthermore, CDOA in the first year posttransplant was associated with an approximately 2-fold increased risk of death-censored graft failure (aHR, 2.29; 95% CL, 1.59–3.32), all-cause graft loss (aHR, 2.09; 95% CL, 1.50–2.91), and death (aHR, 1.79; 95% CL, 1.06–3.04) in the subsequent 2 years. Posttransplant CDOA was also associated with cardiovascular, pulmonary, and psychosocial problems, and with events such as accidents and fractures. Conclusions. Although associations likely, in part, reflect associated conditions or behaviors, clinical diagnosis of CDOA in the year after transplant appears to have prognostic implications for allograft and patient outcomes. Recipients with posttransplant CDOA warrant focused monitoring and support.

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

“…Similarly, in another study, the prevalence of cannabis abuse or dependence was diagnosed among 0.5% of the study population in the years before and 0.3% after transplant [23]. The low rate reported in Alhamad's (2019) study could be because the study population was the Medicare population who were already selected to undergo transplantation [23]. The authors (Alhamed) suspected that those with substance abuse behaviors (that would preclude transplant) were not included in the study, and the diverse coding practice among various treatment providers did not follow the usual rigor that is typically conducted in clinical trials and researches.…”

“…The low rate of marijuana and other substance use could be due to the fact that abstinence was actively encouraged for listing. Similarly, in another study, the prevalence of cannabis abuse or dependence was diagnosed among 0.5% of the study population in the years before and 0.3% after transplant [23]. The low rate reported in Alhamad's (2019) study could be because the study population was the Medicare population who were already selected to undergo transplantation [23].…”

“…Only one study specified if the participants underwent only one type of transplant vs. multi-organ transplant and or if the transplant was the first transplant vs. repeat transplant [20]. The sample sizes of some of the studies varied widely from 27 to 52,689 [8,23].…”

“…Thirteen studies reported the rates of illicit substance use in solid-organ transplant candidates ( Table 1). Seven studies reviewed retrospective data [13][14][15][16][17][18]22], three studies used crosssectional assessment [10,[25][26], one study analyzed the national transplant registry [23], one study utilized prospective study design [19], and one study used a survey [24] to collect data. The sample sizes of these studies ranged from 59 [16] to 52,689 [23].…”

“…Eight studies were on liver transplant, three on kidney transplant, and two on cardiac transplantation. Three studies primarily focused on cannabis use [13,23], one on injection drug use (IDU) [16], three studies did not present data on individual substances [18,[24][25], and the others presented data on multiple substances. In the overall cohort, any illicit drug was used by 35% at some point in time, most frequently cannabis (31%), amphetamine (16%), heroin (5%), cocaine, inhalants, and hallucinogens (8% each)…”