How to adjust drug doses in chronic kidney disease

Prescribing and peritoneal dialysis

Peritoneal dialysis is a home-based therapy for patients with end-stage kidney disease. It is less efficient in removing solutes and fluid than haemodialysis but offers more flexibility and independence. Peritoneal transport characteristics affect the dialysis prescription. The timing of drug administration is independent of the dialysis process except for the administration of intraperitoneal antibiotics. Dose reductions should follow current recommendations for patients with kidney disease. Fluid overload is common in patients undergoing peritoneal dialysis. Residual kidney function can ameliorate this problem and needs to be preserved. Dialysis solutions with high glucose concentrations contribute to adverse metabolic effects. Peritoneal dialysis-related catheter complications and infections may require patients to transition to haemodialysis. Antifungal prophylaxis needs to be co-administered for the duration of antibiotic courses for any indication to reduce the risk of fungal peritonitis. Close communication with the patient's supervising dialysis unit is required.

A focus on CKD reporting and inappropriate prescribing among older patients discharged from geriatric and nephrology units throughout Italy: A nationwide multicenter retrospective cross-sectional study

Older hospitalized patients with chronic kidney disease (CKD) are part of the geriatric population with a substantial risk of potentially inappropriate medication (PIM) use. The high rates of multimorbidity and polypharmacy, along with the progressive decline of eGFR, contribute to increasing the risk of drug–drug and drug–disease interactions, overdosing, and adverse drug reactions (ADRs). In this multicenter cross-sectional study, we aimed to evaluate the prevalence of CKD under-reporting and PIMs among older patients discharged from acute geriatric and nephrology units throughout Italy. Renal function was determined by estimated glomerular filtration rate (eGFR) through the Berlin Initiative Study (BIS) equation; the prevalence of PIMs was calculated by revising drug prescriptions at discharge according to STOPP criteria, Beers criteria, and summaries of product characteristics (smPCs). A descriptive analysis was performed to compare the clinical and pharmacological characteristics of patients in the two distinct settings; univariate and multivariate logistic regression models were performed to explore factors associated with CKD under-reporting in the discharge report forms and PIM prevalence. Overall, the study population consisted of 2,057 patients, aged 83 (77–89) years, more commonly women, with a median of seven (5–10) drugs prescribed at discharge. CKD under-reporting was present in 50.8% of the study population, with higher rates in geriatric vs. nephrology units (71.1% vs. 10.2%, p < 0.001). 18.5% of the study population was discharged with at least one renally inappropriate medication; factors associated with at least one contraindicated drug at discharge were the number of drugs (PR 1.09, 95% CI 1.14–1.19); atrial fibrillation (PR 1.35, 95% CI 1.01–1.81); diabetes (PR 1.61, 95% CI 1.21–2.13); being hospitalized in nephrology units (PR 1.62, 95% CI 1.14–2.31), CKD stage 3b (PR 2.35, 95% CI 1.34–4.13), and stage 4–5 (PR 14.01, 95% CI 7.36–26.72). Conversely, CKD under-reporting was not associated with the outcome. In summary, CKD under-reporting and inappropriate medication use were common in older patients discharged from hospital; the relatively high number of PIMs in both nephrology and geriatric settings underlines the need to improve appropriate prescribing during hospital stay and to decrease the risk of ADRs and side effects in this highly vulnerable population.

Evaluation of medication dose adjustments in patients with impaired renal function using different online drug information databases

OBJECTIVES

Clinical pharmacist-led medication dose adjustment is required to provide safe and effective pharmacotherapy in patients with impaired renal function. This study aimed to assess clinical pharmacist-led medication dose adjustments in hospitalised patients with impaired renal function by comparing three online drug information databases.

METHODS

This retrospective observational study was conducted in an internal medicine ward between November 2016 and February 2017 among hospitalised patients with at least one estimated glomerular filtration rate (eGFR) value <60 mL/min/1.73 m2. Clinical pharmacist-led medication dose adjustments according to eGFR were performed by comparing three online drug information databases: Micromedex, Medscape and Lexicomp. The number of items related to dose adjustments detected during the study period and the concordance between databases were evaluated.

RESULTS

This study was conducted among 100 hospitalised patients (mean age 74.6±13.2 years) with impaired renal function. Clinical pharmacists detected at least one medication dose adjustment in 71.0% of patients. Among these patients, it was found that physician-led medication dose adjustments were made in only 15.5% of them. Of 1053 medications, the number of medications that required dose adjustments were 149 (14.2%), 151 (14.3%) and 163 (15.5%) according to Micromedex, Medscape and Lexicomp, respectively. The Fleiss kappa coefficient was 0.875 and the agreement of the three clinical decision support systems were almost perfect.

CONCLUSIONS

In renal dose adjustments, Micromedex, Lexicomp and Medscape are concordant as online drug information databases. Clinical pharmacists could detect medication dose adjustment requirements in hospital patients with impaired renal function. The potential positive impact of clinical pharmacist-led medication dose adjustment should be investigated in further studies.

Review and evaluation of vancomycin dosing guidelines for obese individuals

INTRODUCTION

Vancomycin dosing decisions are informed by factors such as body weight and renal function. It is important to understand the impact of obesity on vancomycin pharmacokinetics and how this may influence dosing decisions. Vancomycin dosing guidelines use varied descriptors of body weight and renal function. There is uncertainty whether current dosing guidelines result in attainment of therapeutic targets in obese individuals.

AREAS COVERED

Literature was explored using PubMed, Embase and Google Scholar for articles from January 1980 to July 2021 regarding obesity-driven physiological changes, their influence on vancomycin pharmacokinetics and body size descriptors and renal function calculations in vancomycin dosing. Pharmacokinetic simulations reflective of international vancomycin dosing guidelines were conducted to evaluate the ability of using total, ideal and adjusted body weight, as well as Cockcroft-Gault and CKD-EPI equations to attain an area-under-the-curve to minimum inhibitory concentration ratio (AUC₂₄/MIC) target (400-650) in obese individuals.

EXPERT OPINION

Vancomycin pharmacokinetics in obese individuals remains debated. Guidelines that determine loading doses using total body weight, and maintenance doses adjusted based on renal function and adjusted body weight, may be most appropriate for obese individuals. Use of ideal body weight leads to subtherapeutic vancomycin exposure and underestimation of renal function.

Pharmacokinetics and Bioequivalence of Two Empagliflozin, with Evaluation in Healthy Jordanian Subjects under Fasting and Fed Conditions

The current study is a randomized, open-label, two-period, two-sequence, two-way crossover pharmacokinetic study in healthy Jordanian subjects to evaluate the pharmacokinetics and bioequivalence profile of two cases of empagliflozin 10 mg under fasting and fed conditions. The plasma concentrations of empagliflozin were determined using an HPLC-MS/MS method. Tolerability and safety were assessed throughout the study. This study included 26 subjects, 26 in both fasting and fed groups.The pharmacokinetic parameters, which included the area under the concentration–time curve from time zero to infinity (AUC_0–inf) and the final quantifiable concentration (AUC_0–last), maximum serum concentration (C_max), and time to reach the maximum drug concentration (T_max) were found to be within an equivalence margin of 80.00–125.00%. The pharmacokinetic profiles show that the empagliflozin test and parent reference cases were bioequivalent in healthy subjects. The two treatments’ safety evaluations were also comparable.

The Mechanism of Drug Nephrotoxicity and the Methods for Preventing Kidney Damage

Acute kidney injury (AKI) is a global health challenge of vast proportions, as approx. 13.3% of people worldwide are affected annually. The pathophysiology of AKI is very complex, but its main causes are sepsis, ischemia, and nephrotoxicity. Nephrotoxicity is mainly associated with the use of drugs. Drug-induced AKI accounts for 19-26% of all hospitalized cases. Drug-induced nephrotoxicity develops according to one of the three mechanisms: (1) proximal tubular injury and acute tubular necrosis (ATN) (a dose-dependent mechanism), where the cause is related to apical contact with drugs or their metabolites, the transport of drugs and their metabolites from the apical surface, and the secretion of drugs from the basolateral surface into the tubular lumen; (2) tubular obstruction by crystals or casts containing drugs and their metabolites (a dose-dependent mechanism); (3) interstitial nephritis induced by drugs and their metabolites (a dose-independent mechanism). In this article, the mechanisms of the individual types of injury will be described. Specific groups of drugs will be linked to specific injuries. Additionally, the risk factors for the development of AKI and the methods for preventing and/or treating the condition will be discussed.

Clinical significance of serum cystatin C in early evaluation of renal impairment caused by chemotherapy in elderly patients

Background

This study aims to discuss the application value of serum cystatin C (Cys C) in detecting early renal function injury in elderly patients with malignant tumors after chemotherapy.

Methods

The data at different chemotherapy time points (before chemotherapy, after two cycles of chemotherapy, and after four cycles of chemotherapy) were analyzed.

Results

Serum Cys C was significantly higher after chemotherapy than before chemotherapy in elderly patients with malignant tumors, and the endogenous creatinine clearance rate (CCr) significantly decreased. These were significantly correlated. However, there was no significant change in serum creatinine (SCr) and blood urea nitrogen (BUN). Cys C continued to increase with the prolonged time of chemotherapy. In addition, Cys C was sensitive for detecting renal impairment caused by platinum-based chemotherapy drugs.

Conclusions

The diagnostic effect of Cys C on early renal function injury after chemotherapy in elderly patients with malignant tumors is better, when compared to traditional renal function test items, such as SCr, BUN and CCr.