A Real-World Data Derived Pharmacovigilance Assessment on Drug-Induced Nephropathy: Implication on Gaps in Patient Care

This retrospective cross-sectional study aims to investigate the prevalence and seriousness of drug-induced nephrotoxicity and to identify clinical predictors intensifying the seriousness of nephrotoxicity. Adverse drug events (ADEs) reported to the Korean Adverse Event Reporting System Database (KAERS DB) from January 2012 to December 2021 were investigated. The association between the seriousness and the etiologic drug was estimated in reporting odds ratio (ROR) based on disproportionality analysis. Logistic regression was utilized to recognize predictors associated with serious nephrotoxicity. The majority of ADEs were reported in ages 30 to 59, and immunosuppressants were the most etiologic medications. ADEs involving antibiotics, including vancomycin (ROR 0.268; 95% CI 0.129-0.557), were less likely to be serious. More than 93% of cyclosporine-related ADEs were serious nephrotoxicity, whereas tacrolimus was less likely to report serious nephrotoxicity (ROR 0.356; 95% CI 0.187-0.680). The risk of serious nephrotoxicity was decreased with aging (ROR 0.955; 95% CI 0.940-0.972) while increased in women (OR 2.700; 95% CI 1.450-5.008). Polypharmacy was associated with increased risk of interstitial nephritis (OR 1.019; 95% CI 1.001-1.038). However, further studies investigating the impact of clinical practice on ADE incidences as well as clinical prognosis related to nephrotoxicity are obligated.

Assessing Trans-Inhibition of OATP1B1 and OATP1B3 by Calcineurin and/or PPIase Inhibitors and Global Identification of OATP1B1/3-Associated Proteins

Organic anion transporting polypeptide (OATP) 1B1 and OATP1B3 are key determinants of drug-drug interactions (DDIs). Various drugs including the calcineurin inhibitor (CNI) cyclosporine A (CsA) exert preincubation-induced trans-inhibitory effects upon OATP1B1 and/or OATP1B3 (abbreviated as OATP1B1/3) by unknown mechanism(s). OATP1B1/3 are phosphoproteins; calcineurin, which dephosphorylates and regulates numerous phosphoproteins, has not previously been investigated in the context of preincubation-induced trans-inhibition of OATP1B1/3. Herein, we compare the trans-inhibitory effects exerted on OATP1B1 and OATP1B3 by CsA, the non-analogous CNI tacrolimus, and the non-CNI CsA analogue SCY-635 in transporter-overexpressing human embryonic kidney (HEK) 293 stable cell lines. Preincubation (10-60 min) with tacrolimus (1-10 µM) rapidly and significantly reduces OATP1B1- and OATP1B3-mediated transport up to 0.18 ± 0.03- and 0.20 ± 0.02-fold compared to the control, respectively. Both CsA and SCY-635 can trans-inhibit OATP1B1, with the inhibitory effects progressively increasing over a 60 min preincubation time. At each equivalent preincubation time, CsA has greater trans-inhibitory effects toward OATP1B1 than SCY-635. Preincubation with SCY-635 for 60 min yielded IC50 of 2.2 ± 1.4 µM against OATP1B1, which is ~18 fold greater than that of CsA (0.12 ± 0.04 µM). Furthermore, a proteomics-based screening for protein interactors was used to examine possible proteins and processes contributing to OATP1B1/3 regulation and preincubation-induced inhibition by CNIs and other drugs. A total of 861 and 357 proteins were identified as specifically associated with OATP1B1 and OATP1B3, respectively, including various protein kinases, ubiquitin-related enzymes, the tacrolimus (FK506)-binding proteins FKBP5 and FKBP8, and several known regulatory targets of calcineurin. The current study reports several novel findings that expand our understanding of impaired OATP1B1/3 function; these include preincubation-induced trans-inhibition of OATP1B1/3 by the CNI tacrolimus, greater preincubation-induced inhibition by CsA compared to its non-CNI analogue SCY-635, and association of OATP1B1/3 with various proteins relevant to established and candidate OATP1B1/3 regulatory processes.

The Evaluation and Management of Coronary Artery Disease in the Lung Transplant Patient

Lung transplantation can greatly improve quality of life and extend survival in those with end-stage lung disease. In order to derive the maximal benefit from such a procedure, patients must be carefully selected and be otherwise healthy enough to survive a high-risk surgery and sometimes prolonged immunosuppressive therapy following surgery. Patients therefore must be critically assessed prior to being listed for transplantation with close attention paid towards assessment of cardiovascular health and operative risk. One of the biggest dictators of this is coronary artery disease. In this review article, we discuss the assessment and management of coronary artery disease in the potential lung transplant candidate.

Statins in Kidney Transplant Recipients: Usage, All-Cause Mortality, and Interactions with Maintenance Immunosuppressive Agents

SIGNIFICANCE STATEMENT

Cardiovascular diseases account for 32% of deaths among kidney transplant recipients. Statin therapy is common in this population. However, its effect on mortality prevention remains unclear among kidney transplant recipients, whose clinical risk profile might be unique because of concomitant immunosuppressive therapy. In this national study of 58,264 single-kidney transplant recipients, statin use was associated with a 5% decrease in mortality. More importantly, this protective association was stronger among those who used a mammalian target of rapamycin (mTOR) inhibitor for immunosuppression (27% decrease in mTOR inhibitor users versus 5% in nonusers). Our results suggest that statin therapy may reduce mortality in kidney transplant recipients and that the strength of this protective association may vary by immunosuppression regimen.

BACKGROUND

Cardiovascular diseases are the leading cause of mortality in kidney transplant (KT) recipients, accounting for 32% of deaths. Statins are widely used in KT recipients, but effectiveness for preventing mortality remains unclear in this population, especially because of interaction between statins and immunosuppressive agents. We analyzed a national cohort to assess the real-world effectiveness of statins for reducing all-cause mortality in KT recipients.

METHODS

We studied statin use and mortality among 58,264 adults (18 years or older) who received single kidneys between 2006 and 2016 and had Medicare part A/B/D. Statin use was ascertained from Medicare prescription drug claims and deaths from Center for Medicare and Medicaid Services records. We estimated the association of statin use with mortality using multivariable Cox models, with statin use as a time-varying exposure and immunosuppression regimen as effect modifiers.

RESULTS

Statin use increased from 45.5% at KT to 58.2% at 1-year post-KT to 70.9% at 5-year post-KT. We observed 9785 deaths over 236,944 person-years. Overall, statin use was significantly associated with lower mortality (adjusted hazard ratio [aHR], 0.95; 95% confidence interval [CI], 0.90 to 0.99). The strength of this protective association varied by calcineurin inhibitor use (among tacrolimus users, aHR, 0.97; 95% CI, 0.92 to 1.03 versus among calcineurin nonusers, aHR, 0.72; 95% CI, 0.60 to 0.87; interaction P =0.002), mammalian target of rapamycin (mTOR) inhibitor use (among mTOR inhibitor users, aHR, 0.73; 95% CI, 0.57 to 0.92 versus among nonusers, aHR, 0.95; 95% CI, 0.91 to 1.00; interaction P =0.03), and mycophenolate use (among mycophenolate users, aHR, 0.96; 95% CI, 0.91 to 1.02 versus among nonusers, aHR, 0.76; 95% CI, 0.64 to 0.89; interaction P =0.002).

CONCLUSION

Real-world evidence supports statin therapy for reducing all-cause mortality in KT recipients. Effectiveness might be greater when combined with mTOR inhibitor-based immunosuppression.

In vitro validation of an in vivo phenotyping drug cocktail for major drug transporters in humans

PURPOSE

Cocktails of transporter probe drugs are used in vivo to assess transporter activity and respective drug-drug interactions. An inhibitory effect of components on transporter activities should be ruled out. Here, for a clinically tested cocktail consisting of adefovir, digoxin, metformin, sitagliptin, and pitavastatin, inhibition of major transporters by individual probe substrates was investigated in vitro.

METHODS

Transporter transfected HEK293 cells were used in all evaluations. Cell-based assays were applied for uptake by human organic cation transporters 1/2 (hOCT1/2), organic anion transporters 1/3 (hOAT1/3), multidrug and toxin extrusion proteins 1/2K (hMATE1/2K), and organic anion transporter polypeptide 1B1 (hOATP1B1). For P-glycoprotein (hMDR1) a cell-based efflux assay was used whereas an inside-out vesicle-based assay was used for the bile salt export pump (hBSEP). All assays used standard substrates and established inhibitors (as positive controls). Inhibition experiments using clinically achievable concentrations of potential perpetrators at the relevant transporter expression site were carried out initially. If there was a significant effect, the inhibition potency (K_i) was studied in detail.

RESULTS

In the inhibition tests, only sitagliptin had an effect and reduced hOCT1- and hOCT2- mediated metformin uptake and hMATE2K mediated MPP⁺ uptake by more than 70%, 80%, and 30%, respectively. The ratios of unbound C_max (observed clinically) to K_i of sitagliptin were low with 0.009, 0.03, and 0.001 for hOCT1, hOCT2, and hMATE2K, respectively.

CONCLUSION

The inhibition of hOCT2 in vitro by sitagliptin is in agreement with the borderline inhibition of renal metformin elimination observed clinically, supporting a dose reduction of sitagliptin in the cocktail.

Incidence of Statin-Associated Adverse Events in Kidney Transplant Recipients

BACKGROUND

Statins are the third most prescribed drug class in kidney transplant recipients as cardiovascular diseases is the leading cause of death in this population. However, statins' safety profile remains unclear in kidney transplant recipients who are uniquely burdened by concomitant immunosuppression and comorbidities. We conducted a national study to characterize the association of statin use with adverse events in kidney transplant recipients.

METHODS

We studied adult (≥18) single-organ kidney transplant recipients in 2006-2016 with Medicare as primary payer (n=57,699). We used prescription drug claims to capture statin use, and ICD-9/10 diagnosis codes to capture statin-related adverse events (post-transplant diabetes mellitus, hemorrhagic stroke, cataract, liver injury, and rhabdomyolysis). We conducted multivariable Cox regression for each outcome with statin use as a time-varying exposure.

RESULTS

Post-transplant diabetes mellitus was the most common outcome (5-year Kaplan-Meier incidence; 43% in statin users vs. 35% in non-users), followed by cataract (22% vs. 12%), liver injury (2% vs. 3%), hemorrhagic stroke (1.9% vs. 1.4%), and rhabdomyolysis (1.5% vs. 0.9%). In our multivariable analysis, statin use was associated with higher hazard of post-transplant diabetes mellitus (aHR=1.12 [95% CI, 1.07-1.18]), cataract (aHR=1.22 [1.14-1.31]), and rhabdomyolysis (aHR=1.37 [1.10-1.71]), but lower hazard of liver injury (aHR=0.82 [0.71-0.95]). Statin use was not associated with hemorrhagic stroke (aHR=1.04 [0.86-1.26]).

CONCLUSIONS

Statins appear to be generally well-tolerated in kidney transplant recipients. However, statin use might be associated with slightly higher risk of post-transplant diabetes mellitus, cataract, and rhabdomyolysis.

Approach to the Patient With Nonalcoholic Fatty Liver Disease

CONTEXT

Nonalcoholic fatty liver disease (NAFLD) is associated with obesity and type 2 diabetes (T2D), causing substantial burden from hepatic and extrahepatic complications. However, endocrinologists often follow people who are at the highest risk of its more severe form with nonalcoholic steatohepatitis or NASH (i.e., T2D or obesity with cardiometabolic risk factors). Endocrinologists are in a unique position to prevent cirrhosis in this population with early diagnosis and treatment.

OBJECTIVE

This work aims to offer endocrinologists a practical approach for the management of patients with NAFLD, including diagnosis, fibrosis risk stratification, and referral to hepatologists.

PATIENTS

(1) An asymptomatic patient with obesity and cardiometabolic risk factors, found to have hepatic steatosis; (2) a patient with T2D and NASH with clinically significant liver fibrosis; and (3) a liver transplant recipient with a history of NASH cirrhosis, with significant weight regain and with recurrent NAFLD on the transplanted organ.

CONCLUSION

NASH can be reversed with proper management of obesity and of T2D. While no agents are currently approved for the treatment of NASH, treatment should include lifestyle changes and a broader use of structured weight-loss programs, obesity pharmacotherapy, and bariatric surgery. Diabetes medications such as pioglitazone and some glucagon-like peptide 1 receptor agonists may also improve liver histology and cardiometabolic health. Sodium-glucose cotransporter-2 inhibitors and insulin may ameliorate steatosis, but their effect on steatohepatitis remains unclear. Awareness by endocrinologists about, establishing an early diagnosis of fibrosis (ie, FIB-4, liver elastography) in patients at high-risk of cirrhosis, long-term monitoring, and timely referral to the hepatologist are all critical to curve the looming epidemic of cirrhosis from NAFLD.

Lipid management to mitigate poorer postkidney transplant outcomes

PURPOSE OF REVIEW

Lipid disorder is a prevalent complication in kidney transplant recipients (KTRs) resulting in cardiovascular disease (CVD), which influences on patient outcomes. Immunosuppressive therapy demonstrated the major detrimental effects on metabolic disturbances. This review will focus on the effect of immunosuppressive drugs, lipid-lowering agents with current management, and future perspectives for lipid management in KTRs.

RECENT FINDINGS

The main pathogenesis of hyperlipidemia indicates an increase in lipoprotein synthesis whilst the clearance of lipid pathways declines. Optimization of immunosuppression is a reasonable therapeutic strategy for lipid management regarding immunologic risk. Additionally, statin is the first-line lipid-lowering drug, followed by a combination with ezetimibe to achieve the low-density lipoprotein cholesterol (LDL-C) goal. However, drug interaction between statins and immunosuppressive medications should be considered because both are mainly metabolized through cytochrome P450 3A4. The prevalence of statin toxicity was significantly higher when concomitantly prescribed with cyclosporin, than with tacrolimus.

SUMMARY

To improve cardiovascular outcomes, LDL-C should be controlled at the target level. Initiation statin at a low dose and meticulous titration is crucial in KTRs. Novel therapy with proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, which is highly effective in reducing LDL-C and cardiovascular complications, and might prove to be promising therapy for KTRs with statin resistance or intolerance.

Clinical conundrums involving statin drug-drug interactions

Statins are the cornerstone of pharmacologic therapy for the prevention and treatment of atherosclerotic cardiovascular disease. While they are generally considered safe, statins can be affected by drug-drug interactions (DDIs) that increase their systemic exposure increasing the risk for statin-associated muscle symptoms. These interactions are primarily mediated through metabolizing enzymes such as cytochrome P450 isoenzymes and membrane-bound drug transporting proteins including P-glycoprotein and organic ion transporting polypeptide. Recognition and avoidance of clinically significant statin DDIs is important to ensure their safe use. Conversely, concern over statin DDIs that are not clinically significant may lead to inappropriate underutilization or avoidance of statins in patients who would benefit from them. While many statin DDIs are well-characterized, we present several others that are less-well-established which may warrant clinical attention.

Nonallograft Complications of Lung Transplantation

Long-term exposure to immunosuppressive therapy may exacerbate pre-existing medical comorbidities or result in the development of new chronic medical conditions after lung transplantation. This article focuses on common nonallograft complications with the highest impact on short- and long-term outcomes after transplantation. These include diabetes mellitus, hypertension, dyslipidemia, kidney disease (acute and chronic), and malignancy. We discuss evidence-based strategies for the prevention, diagnosis, and management of these nonallograft complications in this article.

Chronic Renal Failure and Cardiovascular Disease: A Comprehensive Appraisal

Coronary artery disease is highly prevalent in patients with chronic kidney disease. The concomitant renal disease often poses a major challenge in decision making as symptoms, cardiac biomarkers and noninvasive studies for evaluation of myocardial ischemia have different sensitivity and specificity thresholds in this specific population. Moreover, the effectiveness and safety of intervention and medical treatment in those patients is of great doubt as most clinical studies exclude patients with advance CKD. In the present paper, we discuss and review the literature in the diagnosis, treatment and prevention of CAD in the acute and chronic setting, in patients with CKD.

Drug-related problems in older patients with advanced chronic kidney disease identified during pretransplant comprehensive geriatric assessment

BACKGROUND

Older patients with advanced chronic kidney disease may be exposed to a higher risk of adverse drug events due to chronic kidney disease and aging. The integration of clinical pharmacist into pretransplant comprehensive geriatric assessment is an opportunity to perform medication optimization.

OBJECTIVE

The aim was to describe drug-related problems in older patients with advanced chronic kidney disease.

METHODS

Observational study was conducted with retrospective data from July 2017 to April 2019. Patients≥65 years with advanced chronic kidney disease, referred by nephrologists for pretransplant comprehensive geriatric assessment were included. During medication optimization, the pharmacist evaluated the appropriateness of each medication prescribed and identified drug-related problems. Any drug-related problem identified lead to a pharmaceutical intervention.

RESULTS

In total, 103 patients were included (74.5±2.9 years, 26.2% female, 47.6% on dialysis). Overall, 394 drug-related problems were identified in 93.2% of patients (3.8±2.4 drug-related problems per patient) during the medication optimization. Cardiovascular medications (25.1%), antithrombotics (13.5%) and drugs for peptic ulcer and reflux disease (10.2%) were the most involved drugs in drug-related problems. Drug-related problems mainly concerned drugs without indication (27.1%), inappropriate method of administration (24.4%) and non-conformity to guidelines (20.1%).

CONCLUSION

A high prevalence of drug-related problems in older patients with advanced chronic kidney disease was identified during medication optimization. The systematic integration of a clinical pharmacist in the multidisciplinary team performing pretransplant comprehensive geriatric assessment may be relevant to detect inappropriate prescriptions and to prevent from adverse drug events.

Multidirectional facets of obesity management in the metabolic syndrome population after liver transplantation

The obesity pandemic has resulted in an increasing demand for liver transplantation and has significantly altered the profile of liver transplant candidates in addition to affecting posttransplantation outcomes. In this review, we discuss a broad range of clinical approaches that warrant attention to provide comprehensive and patient‐centred medical care to liver transplant recipients, and to be prepared to confront the rapidly changing clinical challenges and ensuing dilemmas. Adipose tissue is a complex and metabolically active organ. Visceral fat deposition is a key predictor of overall obesity‐related morbidity and mortality. Limited pharmacological options are available for the treatment of obesity in the liver transplant population. Bariatric surgery may be an alternative in eligible patients. The rapidly increasing prevalence of nonalcoholic fatty liver disease (NAFLD) is a global concern; NAFLD affects both pre‐ and posttransplantation outcomes. Numerous studies have investigated pharmacological and nonpharmacological management of NAFLD and some of these have shown promising results. Liver transplant recipients are constantly exposed to numerous factors that result in intestinal microbiota alterations, which were linked to the development of obesity, diabetes type 2, metabolic syndrome (MS), NAFLD, and hepatocellular cancer. Microbiota modifications with probiotics and prebiotics bring gratifying results in the management of metabolic complications. Fecal microbiota transplantation (FMT) is successfully performed in many medical indications. However, the safety and efficacy profiles of FMT in immunocompromised patients remain unclear. Obesity together with immunosuppressive treatment, may affect the pharmacokinetic and/or pharmacodynamic properties of coadministered medications. Individualized immunosuppressive regimens are recommended following liver transplantation to address possible metabolic concerns. Effective and comprehensive management of metabolic complications is shown to yield multiple beneficial results in the liver transplant population and may bring gratifying results in improving long‐term survival rates.

Adverse effects of immunosuppression after liver transplantation

After solid organ transplantation the cornerstone of immunosuppression is based on calcineurin inhibitors (CNIs), mostly tacrolimus. However, CNIs have a very narrow therapeutic window. The most important and serious side-effects of CNIs are nephrotoxicity, high blood pressure, post-transplant diabetes mellitus (PTMD), i.e., new-onset diabetes after transplantation (NODAT), dyslipidemia, and modification to the cardiovascular-risk profile. In this review, we will focus on tacrolimus-related toxicities in the setting of liver transplantation.

The Underutilization, Adverse Reactions and Efficacy of Statins after Liver Transplant: A Meta-Analysis and Systematic Review

(1) Background: Treatment of dyslipidemia via statin therapy in the non-liver transplant (LT) population is associated with a mortality benefit; however, the impact of statin therapy in post-LT population is not well-defined. This meta-analysis seeks to investigate the safety and efficacy of statin therapy in post-LT patients. (2) Methods: A systematic literature search on Medline and EMBASE database was conducted. A single-arm proportional meta-analysis and conventional pair-wise meta-analysis were performed to compare different outcomes with a random effects model. (3) Results: A total of 11 studies were included in this study, with 697 LT recipients identified to be on statin therapy. Statins were underutilized with only 32% (95% CI: 0.15–0.52) of 1094 post-LT patients on therapy. The incidence of adverse events of 14% (95% CI: 0.05–0.25) related to statin therapy was low. A significant mortality benefit was noted in patients on statin therapy with HR = 0.282 (95% CI: 0.154–0.517, p < 0.001), and improved lipid profiles post LT. The use of statins also significantly decreased odds of graft rejection (OR = 0.33; 95% CI: 0.15–0.73) and hepatocellular carcinoma (HCC) recurrence (HR = 0.32, 95% CI: 0.11–0.89). (4) Conclusions: Statin therapy is safe and efficacious in post-LT patients. Future studies to evaluate the effects of interactions between statins and immunosuppressant therapy are warranted.

Coronavirus Disease 2019 (COVID-19) and Transplantation: Pharmacotherapeutic Management of Immunosuppression Regimen

The 2019 novel coronavirus disease (COVID-19) was first detected in Wuhan, Hubei Province, China, in late 2019. Since then, COVID-19 has spread to more than 200 countries in the world, and a global pandemic has been declared by the World Health Organization (WHO). At present, no vaccines or therapeutic regimens with proven efficacy are available for the management of COVID-19. Hydroxychloroquine/chloroquine, lopinavir/ritonavir, ribavirin, interferons, umifenovir, remdesivir, and interleukin antagonists, such as tocilizumab, have been recommended as potential treatment options in COVID-19. Transplant patients receiving immunosuppressant medications are at the highest risk of severe illness from COVID-19. At the same time, with regard to receiving polypharmacy and immunosuppressants, treatment options should be chosen with more attention in this population. Considering drug-drug interactions and adverse effects of medications used for the treatment of COVID-19, such as QT prolongation, the dose reduction of some immunosuppressants or avoidance is recommended in transplant recipients with COVID-19. Thus, this narrative review describes clinically important considerations about the treatment of COVID-19 and immunosuppressive regimens regarding modifications, side effects, and interactions in adult kidney or liver allograft recipients.