A Synopsis of Clinical Pharmacokinetic Alterations in Advanced CKD

Efficacy and Safety in a Real-World Study of the New Oral Formulation of Semaglutide in Patients with Chronic Kidney Disease and Type 2 Diabetes Mellitus

Background/Objectives: GLP-1 receptor agonists (GLP-1RAs) have emerged as fundamental components in the treatment of type 2 diabetic patients (T2DM) with chronic kidney disease (CKD). The oral formulation represents a novel therapeutic tool but may affect drug efficacy. This study sought to compare the effectiveness of subcutaneous versus oral semaglutide formulations in patients with CKD. Methods: A retrospective study in a real-world setting compared type 2 diabetes and chronic kidney disease patients, initiating oral semaglutide treatment to a historically matched control group treated with subcutaneous semaglutide. The matching considered factors such as estimated glomerular filtration rate (eGFR), age, and sex. Results: Nineteen patients were included in both groups, with a mean age of 68.0. Seventy-two percent were males with a CKD-EPI eGFR of 49.9 mL/min/1.73 m2 and a median urine albumin-to-creatinine ratio of 12.7 mg/g. Of the study participants, 94% and 79% of patients were on the maximum semaglutide sbc vs. oral dose, while 5.3% and 15.8% were on the sbc vs. oral low dose. Oral semaglutide significantly reduced HbA1C and BMI, identical to the control group (-0.9 and -1.4, p > 0.05). Renal function parameters and blood pressure remained stable throughout the follow-up in both groups. The main side effect was digestive intolerance (affecting three patients in the oral group and two patients in the subcutaneous group, p = 0.6), although the treatment abandonment percentage was similar. Conclusions: The oral formulation of semaglutide demonstrated equivalent effectiveness in glucose control and body weight management in patients with T2DM and CKD, even with a higher proportion of patients receiving low to medium doses. Gastrointestinal side effects were comparable between both oral and subcutaneous formulations.

De-indexed estimated glomerular filtration rates for the dosing of oral antidiabetic drugs in patients with chronic kidney disease

Introduction: Adjusting drug dose levels based on equations that standardize the estimated glomerular filtration rate (eGFR) to a body surface area (BSA) of 1.73 m2 can pose challenges, especially for patients with extremely high or low body mass index (BMI). The objective of the present study of patients with CKD and diabetes was to assess the impact of deindexing creatinine-based equations on estimates of kidney function and on the frequency of inappropriate prescriptions of oral antidiabetic drugs (OADs). Methods: The prospective CKD-REIN cohort is comprised of patients with eGFR <60 mL/min/1.73 m2. The inclusion criteria for this study were the use of OADs and the availability of data on weight, height and serum creatinine. We compared data for three BMI subgroups (group 1 <30 kg/m2; group 2 30-34.9 kg/m2; group 3 ≥35 kg/m2). Inappropriate prescriptions (contraindicated or over-dosed drugs) were assessed with regard to the summary of product characteristics and the patient's kidney function estimated with the 2009 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation, the 2021 CKD-EPI equation, the Modification of Diet in Renal Disease (MDRD) equation, the European Kidney Function Consortium (EKFC) equation, their deindexed estimates, and the Cockcroft-Gault (CG) formula. The impact of deindexing the equations was evaluated by assessing 1) the difference between the indexed and deindexed eGFRs, and 2) the difference in the proportion of patients with at least one inappropriate OAD prescription between the indexed and deindexed estimates. Results: At baseline, 694 patients were receiving OADs. The median BMI was 30.7 kg/m2, the mean BSA was 1.98 m2, and 90% of patients had a BSA >1.73 m2. Deindexing the kidney function estimates led to higher eGFRs, especially in BMI group 3. The proportion of patients with at least one inappropriate prescription differed greatly when comparing indexed and deindexed estimates. The magnitude of the difference increased with the BMI: when comparing BMI group 1 with BMI group 3, the difference was respectively -4% and -10% between deindexed 2021 CKD-EPI and indexed CKD-EPI. Metformin and sitagliptin were the most frequent inappropriately prescribed OADs. Conclusion: We highlight significant differences between the BSA-indexed and deindexed versions of equations used to estimate kidney function, emphasizing the importance of using deindexed estimates to adjust drug dose levels - especially in patients with an extreme BMI.

Evolution of Ritlecitinib Population Pharmacokinetic Models During Clinical Drug Development

BACKGROUND

Ritlecitinib is an oral Janus kinase 3/tyrosine kinase expressed in hepatocellular carcinoma family inhibitor undergoing parallel clinical development for alopecia areata, vitiligo, ulcerative colitis, Crohn's disease, and rheumatoid arthritis.

OBJECTIVE

As studies read out simultaneously, strategic planning of population pharmacokinetic model development and evaluation is required to ensure timely decisions.

METHODS

Data from healthy participants and patients from 12 clinical trials between December 2014 and July 2021 were included: seven phase I studies in healthy participants and organ impairment, five phase II/III studies in patients with rheumatoid arthritis, ulcerative colitis, alopecia areata, and vitiligo. Population pharmacokinetic models consisted of stepwise procedures to accommodate data availability and the model's application to answering clinical development questions. At each iteration of the model update, parameters of the next model were re-estimated by leveraging previous information and new data.

RESULTS

Three model development lifecycle iterations of the ritlecitinib population pharmacokinetic model were conducted to support alopecia areata, vitiligo, and ulcerative colitis study readouts. Initial structural modeling based on healthy participant data (and some rheumatoid arthritis and alopecia areata data) in iteration 1 provided a platform for comprehensive covariate testing during iteration 2, and model evaluation and implementation of the frequentist prior approach in iteration 3. The final model was a two-compartment model with first-order absorption and direct-response non-stationary clearance and bioavailability driven by concentrations in the peripheral compartment.

CONCLUSIONS

The present approach demonstrated the evolution of three population pharmacokinetic models with accumulating data, addressed clinical drug development questions related to systemic exposures of ritlecitinib, and informed the approved product label.

CLINICAL TRIAL REGISTRATION

NCT02309827, NCT02684760, NCT02958865, NCT02969044, NCT03232905, NCT03732807, NCT04016077, NCT03715829, NCT04037865, NCT04004663, NCT04634565, NCT02974868.

Community pharmacists' perspectives on assessing kidney function and medication dosing for patients with advanced chronic kidney disease: A qualitative study using the theoretical domains framework

Background

The kidneys are responsible for the elimination of many drugs. Chronic kidney disease (CKD) is common, and medications may require adjustment to avoid adverse outcomes. Despite the availability of kidney drug dosing resources, people with CKD are at risk of inappropriate drug prescribing. Community pharmacists are in the ideal position to mitigate harm from inappropriate prescribing in this population.

Methods

In this qualitative study, community pharmacists were interviewed on their perspective on kidney function assessment and dose adjustment in people with advanced CKD (estimated glomerular filtration rate <30 mL/min/1.73 m2). The theoretical domains framework for targeting behavioural change was used to inform the interview guide and analysis. Purposeful sampling was employed until data saturation. Semistructured virtual interviews were audio-recorded, transcribed verbatim and uploaded into NVIVO 12 Pro to facilitate thematic analysis. Deductive and inductive iterative coding approaches were employed to determine categories and themes.

Results

Twelve pharmacists were interviewed, with a mean age of 42 years and 16 years of experience. Four themes comprising 10 categories were identified to influence kidney function assessment and dosing, including resources (information access, technology, references), environment (pharmacy infrastructure, practice setting), reflection (triggers, experience and training, collaboration) and leadership and governance (pharmacist role, advocacy). Feedback on an optimal CKD tool was collected, and enabling themes (categories) for implementation included knowledge and skills (education, training) and reflection (role, support, integration).

Conclusions

Findings will inform the interventions needed to improve implementation of kidney assessment and dosing of high-risk medications in people with kidney impairment into community pharmacy practice. Can Pharm J (Ott) 2023;156:xx-xx.

Structure and Function of a Provincial Renal Pharmacy Program: Applying the Chronic Care Model to Address Equitable Access to Medication and Pharmacy Services

Purpose

We described the rationale, structure, design, and components of a provincial pharmacy services network for patients with kidney disease as a model for enabling equitable access and universal care to pharmacy services and medications across a wide range of clinical conditions, and geographic expanse in British Columbia (BC).

Sources of Information

These include minutes from 53 Pharmacy Services and Formulary (PS&F) Committee meetings held from 1999 to November 2022, documentation available on the British Columbia Renal (BCR) website, direct observation and participation in committee meetings, as well as interviews with key individuals involved in different aspects of the program.

Methods

We reviewed documents and data describing the evolution, rationale, and functioning of the BCR provincial pharmacy services system and used a variety of sources as mentioned above. In addition, a qualitative thematic synthesis of reports of chronic care models (CCMs) was conducted to map the program components into the chronic disease management models.

Key Findings

The components of the provincial pharmacy program (PPP) include (1) a PS&F committee, with interdisciplinary and geographical representation; (2) a community of dispensing pharmacies with standardized protocols and information; (3) a dedicated medication and pharmacy services budget, and regular evaluation of budget, outcomes, and performance; (4) provincial contracts for specific medications; (5) communication and education; and (6) information management system. Program components are described in the context of chronic disease management models. The PPP includes dedicated formularies for people with kidney disease at different points in the disease trajectory, including those on and off dialysis. Equitable access to medications is supported across the province. All medications and counseling services are provided to all patients registered in the program, through a robust distributed model, including community- and hospital-based pharmacies. Provincial contracts managed centrally ensure best economic value, and centralized education and accountability structures ensure sustainability.

Limitations

Limitations of the current report include lack of formal evaluation of the program on patient outcomes, but this is relative as the intention of this article is to describe the program which has existed for over 20 years and is fully functional. Formal evaluation of a complex system would include by costs, cost avoidance, provider, and patients' satisfaction. We are developing a formal plan for this reason.

Implications

The PPP is embedded in the provincial infrastructure of BCR and enables the provision of essential medications and pharmacy services for patients with kidney disease throughout the spectrum. The leveraging of local and provincial resources, knowledge, and expertise to implement a comprehensive PPP, ensures transparency and accountability and may serve as a model for other jurisdictions.

Pattern, frequency and factors associated with inappropriate high dosing in chronic kidney disease patients at a tertiary care hospital in Pakistan

BACKGROUND

Patients with chronic kidney diseases (CKD) are susceptible to the toxic drug effects if given unadjusted doses. Although Pakistan harbors a high burden of CKD patients, there is limited information available on the frequency, pattern and factors associated with unadjusted drug doses among CKD patients.

METHODS

This cross-sectional study conducted at Sandeman Provincial Hospital, Quetta included 303 non-dialysis ambulatory CKD patients (glomerular filtration rate < 60 ml/min/1.73m²). The patients' data were collected through a purpose designed data collection form. The appropriateness of doses was checked against the renal drug handbook-2018, Kidney Disease Improving Global Outcomes guidelines, British National Formulary-2022, and manufacturer leaflets. Data were analysed by SPSS 23 and multiple binary logistic regression analysis was used to assess the factors associated with receiving inappropriate high doses. A p-value < 0.05 was considered statistically significant.

RESULTS

The patients received a total of 2265 prescription lines, with a median of eight different drugs per patient (interquartile range: 6-9 drugs). A total of 34.5% (783/2265) drugs required dose adjustment. Of these, doses were not adjusted for 56.1% (440) drugs in 162 (53.4%) patients. The most common pharmacological class of drugs requiring dose adjustment were antibiotics (79.1%), followed by antidiabetics (59.2%), diuretics (57.0%), angiotensin converting enzyme inhibitors (56.9%), beta blockers (56.9%), analgesics (56.0%), angiotensin receptor blockers (55.2%), domperidone (53.9%) and antihyperlipidmics (46.1%). Patient's age of 41-60 (OR = 5.76) and > 60 years (OR = 9.49), hypertension (OR = 2.68), diabetes mellitus (OR = 3.47) and cardiovascular diseases (OR = 2.82) had statistically significant association (p-value < 0.05) with inappropriate high doses.

CONCLUSION

The high frequency of inappropriate high doses suggests an important quality gap in medication dosing for patients with ND-CKD at the study site. Special attention should be paid to the drugs and patients with identified risk factors for receiving inappropriate high doses.

Anticancer drug therapy for patients with renal dysfunction

Anticancer drug therapy for cancer is developing rapidly, including molecular-targeted drugs and immune checkpoint inhibitors that are used in clinical settings in addition to conventional cytotoxic drugs. In daily clinical practice, clinicians sometimes encounter situations in which the effects of these chemotherapeutic agents are considered unacceptable in high-risk patients with liver or renal dysfunction, those undergoing dialysis and older adults. There is no clear evidence regarding anticancer drugs administration to patients with renal dysfunction. However, there are indications for dose setting based on the theory of the renal function responsible for drug excretion and past administration experience. This review outlines anticancer drugs' administration in patients with renal dysfunction.

The Impact of Suboptimal 25-Hydroxyvitamin D Levels and Cholecalciferol Replacement on the Pharmacokinetics of Oral Midazolam in Control Subjects and Patients With Chronic Kidney Disease

The aim of this study was to investigate the impact of suboptimal 25-hydroxyvitamin D (25-VitD) and cholecalciferol (VitD3 ) supplementation on the pharmacokinetics of oral midazolam (MDZ) in control subjects and subjects with chronic kidney disease (CKD). Subjects with CKD (n = 14) and controls (n = 5) with suboptimal 25-VitD levels (<30 ng/mL) were enrolled in a 2-phase study. In phase 1 (suboptimal), subjects were administered a single oral dose of VitD3 (5000 IU) and MDZ (2 mg). In phase 2 (replete) subjects who achieved 25-VitD repletion after receiving up to 16 weeks of daily cholecalciferol were given the identical single oral doses of VitD3 and MDZ as in phase 1. Concentrations of MDZ and metabolites, 1'-hydroxymidazolam (1'-OHMDZ), and 1'-OHMDZ glucuronide (1'-OHMDZ-G) were measured by liquid chromatography-tandem mass spectrometry and pharmacokinetic analysis was performed. Under suboptimal 25-VitD, reductions in MDZ clearance and renal clearance of 47% and 87%, respectively, and a 72% reduction in renal clearance of 1'-OHMDZ-G were observed in CKD vs controls. In phase 1 versus phase 2, MDZ clearance increased in all control subjects, with a median (interquartile range) increase of 10.5 (0.62-16.7) L/h. No changes in MDZ pharmacokinetics were observed in subjects with CKD between phases 1 and 2. The effects of 25-VitD repletion on MDZ disposition was largely observed in subjects without kidney disease. Impaired MDZ metabolism and/or excretion alterations due to CKD in a suboptimal 25-VitD state may not be reversed by cholecalciferol therapy. Suboptimal 25-VitD may augment the reductions in MDZ and 1'-OHMDZ-G clearance values observed in patients with CKD.

In-Hospital Prescription Checking System for Hospitalized Patients with Decreased Glomerular Filtration Rate

Background

Clinical decision support systems (CDSS) are reported to be useful in preventing dosage errors in renally excreted drugs by alerting hospital pharmacists to inadequate dosages for hospitalized patients with decreased GFR. However, it is unclear whether CDSS can reduce dosage errors in renally excreted drugs in hospitalized patients. To prevent dosage errors in renally excreted drugs, we introduced a prescription checking system (PCS) for in-hospital prescriptions. This retrospective study aimed to evaluate whether a prescription audit by hospital pharmacists using the PCS reduced the rate of dosage errors in renally excreted drugs.

Methods

The target drugs were allopurinol, cibenzoline, famotidine, and pilsicainide. Interrupted time series analysis was used to evaluate trends in the 4-weekly dosage error rates over 52 weeks before PCS implementation and 52 weeks after PCS implementation.

Results

Before and after PCS implementation, 474 and 331 prescriptions containing one of the targeted drugs, respectively, were generated. The estimated baseline level of the 4-weekly dosage error rates was 34%. The trend before the PCS implementation was stable with no observable trend. The estimated level change from the last point in the pre-PCS implementation to the first point in the PCS implementation was -20% (P<0.001). There was no change in the trend after PCS implementation.

Conclusions

We demonstrated that a prescription audit by hospital pharmacists using the PCS reduced the rate of dosage errors in the target renally excreted drugs in hospitalized patients. Although further studies are needed to confirm whether our results can be generalized to other health facilities, our findings highlight the need for a PCS to prevent the overdose of renally excreted drugs.

Advanced oxidation protein products upregulate ABCB1 expression and activity via HDAC2-Foxo3α-mediated signaling in vitro and in vivo

The unpredictable pharmacokinetics of non-renal cleared drugs in chronic kidney disease (CKD) patients is associated with the activity of drug transporters. However, the mechanisms underlying regulation of drug transporters are yet to be established. In this study, we demonstrated the involvement of a HDAC2-Foxo3α pathway in advanced oxidation protein products (AOPPs)-induced ATP-binding cassette subfamily B member 1 (ABCB1) expression and activity. The correlation of AOPPs accumulation with concentration of cyclosporine in plasma was evaluated in 194 patients with transplantation. Molecular changes in acetylation of various histones and related regulatory molecules were examined in HepG2 cell cultures treated with AOPPs. Accumulation of AOPPs in serum in relation to molecular changes in HDAC2-Foxo3α in vivo were evaluated in 5/6 nephrectomy (5/6 nx) and oral adenine (Adenine) CKD rat models. Interestingly, the cyclosporine level was negatively correlated with AOPPs in plasma. In addition, AOPPs markedly suppressed the expression of histone deacetylase 2 (HDAC2), inducing ABCB1 expression and activity in vitro and in vivo. Importantly, AOPPs modulated phosphorylation of Foxo3α and the upstream Akt protein. Our findings indicate that AOPPs regulate the expression and activity of ABCB1 via reducing HDAC2 expression and activating Foxo3α-dependent signaling. The collective results support the utility of AOPPs as a potential target for drug and/or dosage adjustment in CKD patients. Targeting of AOPPs presents a novel approach to regulate non-renal clearance.

Use of Physiologically Based Pharmacokinetic Modeling to Evaluate the Impact of Chronic Kidney Disease on CYP3A4-Mediated Metabolism of Saxagliptin

We characterized the impact of chronic kidney disease (CKD) on the cytochrome P450 (CYP) 3A4–mediated metabolism of saxagliptin to its metabolite, 5‐hydroxysaxagliptin, using a physiologically based pharmacokinetic (PBPK) model. A PBPK model of saxagliptin and its CYP3A4 metabolite, 5‐hydroxysaxagliptin, was constructed and validated for oral doses ranging from 5 to 100 mg. The observed ratios of area under the plasma concentration–time curve (AUC) and maximum plasma concentration (C_max) between healthy subjects and subjects with CKD were compared with those predicted using PBPK model simulations. Simulations were performed with virtual CKD populations having decreased CYP3A4 activity (ie, 64%‐75% of the healthy subjects’ CYP3A4 abundance) and preserved CYP3A4 activity (ie, 100% of the healthy subjects’ CYP3A4 abundance). We found that simulations using decreased CYP3A4 activity generally overpredicted the ratios of saxagliptin AUC and C_max in CKD compared with those using preserved CYP3A4 activity. Similarly, simulations using decreased CYP3A4 activity underpredicted the ratio of 5‐hydroxysaxagliptin AUC in moderate and severe CKD compared with simulations using preserved CYP3A4 activity. These findings suggest that decreased CYP3A4 activity in CKD underpredicts saxagliptin clearance compared with that observed clinically. Preserving CYP3A4 activity in CKD more closely estimates saxagliptin clearance and 5‐hydroxysaxagliptin exposure changes observed in vivo. Our findings suggest that there is no clinically meaningful impact of CKD on the metabolism of saxagliptin by CYP3A4. Since saxagliptin is not a highly sensitive substrate and validated probe for CYP3A4, this work represents a case study of a CYP3A4 substrate‐metabolite pair and is not a generalization for all CYP3A4 substrates.

Personalization of drug dose thematic issue: introduction article

INTRODUCTION

The need to individualize a drug dosage and adjust it to a patient's physiological and/or pathophysiological status is rarely satisfied in routine clinical practice, primarily because of complexity of the adjustment task.

AREAS COVERED

The aim of this article is to shed light to basic principles of drug dosage individualization in the most frequent clinical states that affect pharmacokinetics of drugs. The principles are derived from published clinical studies conducted on diverse patient populations, using non-compartmental pharmacokinetic model.

EXPERT OPINION

Simple, but sufficiently exact, way to calculate appropriate drug dose for a patient is the one based on target average steady-state concentration and non-compartmental pharmacokinetic model. If target steady-state drug concentration and dosage interval are considered fixed, maintenance dose could be adjusted on the basis of expected changes of total drug clearance and bioavailability, while loading dose should be related to changes of volume of distribution and bioavailability. Relative increase or decrease of these pharmacokinetic parameters in regard to normal values in healthy persons is translated to relative (percentual) increase or decrease of maintenance and loading doses recommended in the drug monograph.

Direct Oral Anticoagulant Use in Special Populations: Elderly, Obesity, and Renal Failure

PURPOSE OF REVIEW

The purpose of this review is to examine the safety and effectiveness of direct oral anticoagulants and provide recommendations for the treatment of venous thromboembolism and atrial fibrillation in obese patients, elderly patients, and patients with chronic kidney disease.

RECENT FINDINGS

Multiple retrospective cohort studies have shown no difference in bleeding, stroke, or venous thromboembolism outcomes between DOACs and warfarin in patients who are obese, elderly, or those with chronic kidney disease or on dialysis. Some studies have shown that DOACs have a lower bleeding risk than warfarin in these populations. DOACs may be a safe and effective alternative to warfarin for the prevention of stroke in atrial fibrillation patients who are obese, elderly, or those with chronic kidney disease or on dialysis. Apixaban may improve clinical outcomes by lowering the risk of bleeding versus warfarin. DOACs may also be an effective and safe alternative to warfarin for the treatment of venous thromboembolism in obese patients; however, additional studies are needed to assess their use in elderly patients and those with CKD.

A systematically collated library of prescribing safety indicators for people with chronic kidney disease

BACKGROUND

People with chronic kidney disease (CKD) have high levels of co-morbidity and polypharmacy placing them at increased risk of prescribing-related harm. Tools for assessing prescribing safety in the general population using prescribing safety indicators (PSIs) have been established. However, people with CKD pose different prescribing challenges to people without kidney disease. Therefore, PSIs designed for use in the general population may not include all PSIs relevant to a CKD population. The aim of this study was to systematically collate a library of PSIs relevant to people with CKD.

METHODS

A systematic literature search identified papers reporting PSIs. CKD-specific PSIs were extracted and categorised by Anatomical Therapeutic Chemical (ATC) classification codes. Duplicate PSIs were removed to create a final list of CKD-specific PSIs.

RESULTS

Nine thousand, eight hundred fifty-two papers were identified by the systematic literature search, of which 511 proceeded to full text screening and 196 papers were identified as reporting PSIs. Following categorisation by ATC code and duplicate removal, 841 unique PSIs formed the final set of CKD-specific PSIs. The five ATC drug classes containing the largest proportion of CKD-specific PSIs were: Cardiovascular system (26%); Nervous system (13.4%); Blood and blood forming organs (12.4%); Alimentary and metabolism (12%); and Anti-infectives for systemic use (11.3%).

CONCLUSION

CKD-specific PSIs could be used alone or alongside general PSIs to assess the safety and quality of prescribing within a CKD population.

Adverse Drug Reactions in Patients with CKD

BACKGROUND AND OBJECTIVES

Little is known about the burden of adverse drug reactions in CKD. We estimated the incidence of overall and serious adverse drug reactions and assessed the probability of causation, preventability, and factors associated with adverse drug reactions in patients seen by nephrologists.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Chronic Kidney Disease-Renal Epidemiology and Information Network cohort included 3033 outpatients (65% men) with CKD and eGFR<60 ml/min per 1.73 m², with follow-up for 2 years. Adverse drug reactions were identified from hospitalization reports, medical records, and participant interviews and finally assessed for causality, preventability, and immediate therapeutic management by experts in pharmacology.

RESULTS

Median (interquartile range) age was 69 (60-76) years old; 55% had eGFR≥30 ml/min per 1.73 m², and 45% had eGFR<30 ml/min per 1.73 m². Participants were prescribed a median (range) of eight (five to ten) drugs. Over 2 years, 536 patients had 751 adverse drug reactions, 150 (in 125 participants) classified as serious, for rates of 14.4 (95% confidence interval, 12.6 to 16.5) and 2.7 (95% confidence interval, 1.7 to 4.3) per 100 person-years, respectively. Among the serious adverse drug reactions, 32% were considered preventable or potentially preventable; 16 caused death, directly or indirectly. Renin-angiotensin system inhibitors (15%), antithrombotic agents (14%), and diuretics (10%) were the drugs to which the most adverse drug reactions were imputed, but antithrombotic agents caused 34% of serious adverse drug reactions. The drug was discontinued in 71% of cases, at least temporarily. Adjusted hazard ratios for serious adverse drug reaction were significantly higher in patients with eGFR<30 versus ≥30 ml/min per 1.73 m² (1.8; 95% confidence interval, 1.3 to 2.6), in those prescribed more than ten versus less than five medications (2.4; 95% confidence interval, 1.1 to 5.2), or in those with poor versus good adherence (1.6; 95% confidence interval, 1.4 to 2.4).

CONCLUSIONS

Adverse drug reactions are common and sometimes serious in patients with CKD. Many serious adverse drug reactions may be preventable. Some specific pharmacologic classes, particularly antithrombotic agents, are at risk of serious adverse drug reactions.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Chronic Kidney Disease-Renal Epidemiology and Information Network (CKD-REIN), NCT03381950.

Pharmacokinetics in children with chronic kidney disease

In children, the main causes of chronic kidney disease (CKD) are congenital diseases and glomerular disorders. CKD is associated with multiple physiological changes and may therefore influence various pharmacokinetic (PK) parameters. A well-known consequence of CKD on pharmacokinetics is a reduction in renal clearance due to a decrease in the glomerular filtration rate. The impact of renal impairment on pharmacokinetics is, however, not limited to a decreased elimination of drugs excreted by the kidney. In fact, renal dysfunction may lead to modifications in absorption, distribution, transport, and metabolism as well. Currently, insufficient evidence is available to guide dosing decisions on many commonly used drugs. Moreover, the impact of maturation on drug disposition and action should be taken into account when selecting and dosing drugs in the pediatric population. Clinicians should take PK changes into consideration when selecting and dosing drugs in pediatric CKD patients in order to avoid toxicity and increase efficiency of drugs in this population. The aim of this review is to summarize known PK changes in relation to CKD and to extrapolate available knowledge to the pediatric CKD population to provide guidance for clinical practice.

Dose recommendations for anticancer drugs in patients with renal or hepatic impairment

Renal or hepatic impairment is a common comorbidity for patients with cancer either because of the disease itself, toxicity of previous anticancer treatments, or because of other factors affecting organ function, such as increased age. Because renal and hepatic function are among the main determinants of drug exposure, the pharmacokinetic profile might be altered for patients with cancer who have renal or hepatic impairment, necessitating dose adjustments. Most anticancer drugs are dosed near their maximum tolerated dose and are characterised by a narrow therapeutic index. Consequently, selecting an adequate dose for patients who have either hepatic or renal impairment, or both, is challenging and definitive recommendations on dose adjustments are scarce. In this Review, we discuss the effect of renal and hepatic impairment on the pharmacokinetics of anticancer drugs. To guide clinicians in selecting appropriate dose adjustments, information from available drug labels and from the published literature were combined to provide a practical set of recommendations for dose adjustments of 160 anticancer drugs for patients with hepatic and renal impairment.

Advanced oxidation protein products upregulate efflux transporter expression and activity through activation of the Nrf-2-mediated signaling pathway in vitro and in vivo

Clinical and benchtop studies suggest that chronic kidney disease (CKD) alters both renal and nonrenal clearance of drugs. Although studies have documented that the accumulating uremic toxins in the body under CKD conditions are humoral factors that alter the expression and/or activity of drug transporters, the specific process is poorly understood. In this study, we found that advanced oxidation protein products (AOPPs), which are a modified protein uremic toxin, could upregulate efflux transporters, including P-glycoprotein (ABCB1), multi-drug resistance-associated protein 2 (ABCC2) and breast cancer resistance protein (ABCG2) expression in CKD rat models and in HepG2 cells. Our research shows that renal function decline was associated with the accumulation of AOPPs in serum and the upregulation of efflux transporters in the liver in two rat models of CKD. In HepG2 cells, AOPPs significantly increased the expression of efflux transporters in a dose- and time-dependent manner and upregulated the mRNA expression, protein expression and activity of efflux transporters, but bovine serum albumin (BSA), a synthetic precursor of AOPPs, had no effect. This effect correlated with AOPPs activation of the nuclear factor E2-related factor 2 (Nrf-2)-mediated signaling pathway. Further investigation of the regulation of Nrf-2 by AOPPs revealed that ML385 and siNrf-2 abolished the upregulatory effects of AOPPs. These findings suggest that AOPPs upregulate ABCB1, ABCG2 and ABCC2 through Nrf-2 signaling pathways. Protein uremic toxins, such as AOPPs, may modify the nonrenal clearance of drugs in patients with CKD through effects on drug transporters.

Pharmacotherapeutic Management of Neuropathic Pain in End-Stage Renal Disease

Background

Chronic noncancer pain is pervasive throughout the general patient population, transcending all chronic disease states. Patients with end-stage renal disease (ESRD) present a complicated population for which medication management requires careful consideration of the pathogenesis of ESRD and intimate knowledge of pharmacology. The origin of pain must also guide treatment options. As such, the presentation of neuropathic pain in ESRD can present a challenging case. The authors aim to provide a review of available classes of medications and considerations for the treatment of neuropathic pain in ESRD.

Summary

In this narrative review, the authors discuss important strategies and considerations for the treatment of neuropathic pain in ESRD, including the pathogenesis of neuropathic pain, physiological changes for consideration in ESRD patients, and disease-specific consideration for medication selection. Pharmacotherapeutic classes discussed include: anticonvulsants, antiarrhythmics, antidepressants, topicals, and opioids.

Key Message

Pain management in ESRD patients requires careful assessment of drug-specific properties, accumulation, metabolism (presence of active/toxic metabolites), extraction by dialysis, and presence of drug - drug interactions. In the absence of pharmacokinetic data in ESRD patients, therapeutic window and potential risks should be factored in the decision making along with continued monitoring throughout therapy.

Emerging Roles of Aryl Hydrocarbon Receptors in the Altered Clearance of Drugs during Chronic Kidney Disease

Chronic kidney disease (CKD) is a major public health problem, since 300,000,000 people in the world display a glomerular filtration rate (GFR) below 60 mL/min/1.73m². Patients with CKD have high rates of complications and comorbidities. Thus, they require the prescription of numerous medications, making the management of patients very complex. The prescription of numerous drugs associated with an altered renal- and non-renal clearance makes dose adjustment challenging in these patients, with frequent drug-related adverse events. However, the mechanisms involved in this abnormal drug clearance during CKD are not still well identified. We propose here that the transcription factor, aryl hydrocarbon receptor, which is the cellular receptor for indolic uremic toxins, could worsen the metabolism and the excretion of drugs in CKD patients.

Evaluation of the adequacy of drug prescriptions in patients with chronic kidney disease: results from the CKD-REIN cohort

AIMS

Drug prescription is difficult to manage in patients with chronic kidney disease (CKD). We assessed the prevalence and determinants of inappropriate drug prescriptions (whether contraindications or inappropriately high doses) with regard to kidney function in patients with CKD under nephrology care. We also assessed the impact of the equation used to estimate GFR on the prevalence estimates.

METHODS

The CKD-REIN cohort includes 3033 outpatients with CKD (eGFR between 15 and 60 ml min-1  1.73 m-2 ). We examined the daily doses of pharmacological agents prescribed at study entry. Inappropriate prescription was defined as the reported prescription of either a contraindicated drug or an indicated drug at an inappropriately high dose level with regard to the patient's GFR, as estimated with the CKD-EPI equation, the de-indexed CKD-EPI equation, or the Cockcroft-Gault (CG) equation. Multivariate logistic regression was used to assess the determinants of inappropriate prescription risk.

RESULTS

At baseline, patients' median [interquartile range] number of drugs prescribed per patient was 8 [5-10]. Half of the patients had been prescribed at least one inappropriate drug. Anti-gout, cardiovascular agents and antidiabetic agents accounted for most of the inappropriate prescriptions. The percentage of inappropriate prescriptions varied from one GFR equation to another: 52% when using the CKD-EPI equation, 47% when using the de-indexed CKD-EPI equation and 41% with the CG equation. A multiple logistic regression analysis showed significantly higher odds ratios [95% confidence interval] for inappropriate prescriptions in male patients (1.28 [1.07; 1.53]), patients with diabetes (1.34 [1.06; 1.70]), those with a high BMI (1.58 [1.25; 1.99]), and those with a low GFR (10.2 [6.02; 17.3]). The risk of having at least one inappropriate prescription increased with the number of drugs per patient (P for trend < 0.0001) and therefore the odds ratio was 5.88 [4.17; 8.28] for those who received at least 11 prescribed medications compared to those who received fewer than 5.

CONCLUSION

Our results emphasize the complexity of drug management for CKD patients, for whom inappropriate prescription appears to be common.

Clinical Pharmacogenomics: Applications in Nephrology

Pharmacogenomics is a tool for practitioners to provide precision pharmacotherapy using genomics. All providers are likely to encounter genomic data in practice with the expectation that they are able to successfully apply it to patient care. Pharmacogenomics tests for genetic variations in genes that are responsible for drug metabolism, transport, and targets of drug action. Variations can increase the risk for drug toxicity or poor efficacy. Pharmacogenomics can, therefore, be used to help select the best medication or aid in dosing. Nephrologists routinely treat cardiovascular disease and manage patients after kidney transplantation, two situations for which there are several high-evidence clinical recommendations for commonly used anticoagulants, antiplatelets, statins, and transplant medications. Successful use of pharmacogenomics in practice requires that providers are familiar with how to access and use pharmacogenomics resources. Similarly, clinical decision making related to whether to use existing data, whether to order testing, and if data should be used in practice is needed to deliver precision medicine. Pharmacogenomics is applicable to virtually every medical specialty, and nephrologists are well positioned to be implementation leaders.

Indoxyl Sulfate Upregulates Liver P-Glycoprotein Expression and Activity through Aryl Hydrocarbon Receptor Signaling

In patients with CKD, not only renal but also, nonrenal clearance of drugs is altered. Uremic toxins could modify the expression and/or activity of drug transporters in the liver. We tested whether the uremic toxin indoxyl sulfate (IS), an endogenous ligand of the transcription factor aryl hydrocarbon receptor, could change the expression of the following liver transporters involved in drug clearance: SLC10A1, SLC22A1, SLC22A7, SLC47A1, SLCO1B1, SLCO1B3, SLCO2B1, ABCB1, ABCB11, ABCC2, ABCC3, ABCC4, ABCC6, and ABCG2 We showed that IS increases the expression and activity of the efflux transporter P-glycoprotein (P-gp) encoded by ABCB1 in human hepatoma cells (HepG2) without modifying the expression of the other transporters. This effect depended on the aryl hydrocarbon receptor pathway. Presence of human albumin at physiologic concentration in the culture medium did not abolish the effect of IS. In two mouse models of CKD, the decline in renal function associated with the accumulation of IS in serum and the specific upregulation of Abcb1a in the liver. Additionally, among 109 heart or kidney transplant recipients with CKD, those with higher serum levels of IS needed higher doses of cyclosporin, a P-gp substrate, to obtain the cyclosporin target blood concentration. This need associated with serum levels of IS independent of renal function. These findings suggest that increased activity of P-gp could be responsible for increased hepatic cyclosporin clearance. Altogether, these results suggest that uremic toxins, such as IS, through effects on drug transporters, may modify the nonrenal clearance of drugs in patients with CKD.

Guidance to develop individual dose recommendations for patients on chronic hemodialysis

INTRODUCTION

In addition to tailored clinical trials in patients on chronic hemodialysis (HD) during drug development, clinician-initiated post-marketing studies and case reports on individual pharmacokinetic (PK) assessments provide an important source of information about drug dialysability and individualized dose recommendations in this vulnerable population. Areas covered: First, factors that may alter drug exposure in HD patients are explained. Second, available regulatory and methodological guidelines for PK assessments in this population are summarized. Third, a 4-step approach is proposed to develop individual dose recommendations for HD patients receiving drugs without data from a PK study: (1) literature search, (2) model-based dosage decisions, (3) validation and refinement through concentration monitoring, and (4) publication of relevant observations. Fourth, clinician-initiated PK assessments and case reports to evaluate and individualize use of drugs in HD patients are reviewed, and recommendations to enhance their quality are discussed. Expert commentary: Guidance on collecting and reporting PK information in individual HD patients is warranted to ensure completeness and consistency of such PK studies. A checklist and template for easy-to-implement PK calculations and pharmacometric modeling is provided to facilitate evaluation and individualization of dosing strategies in these patients.