Automating and estimating glomerular filtration rate for dosing medications and staging chronic kidney disease

Drug-Related Problems in Hospitalised Patients with Chronic Kidney Disease: A Systematic Review

INTRODUCTION

Globally, chronic kidney disease (CKD) is one of the leading causes of mortality. Impaired renal function makes CKD patients vulnerable to drug-related problems (DRPs).

AIM

The aim of this systematic review was to investigate the prevalence and nature of DRPs among hospital in-patients with CKD.

METHODS

A systematic review of the literature was conducted using Medline, EMBASE, PsycINFO, Web of Science (Core Collection), CINAHL plus (EBSCO), Cochrane Library (Wiley), Scopus (ELSEVIER) and PubMed (U.S.NLM) from index inception to January 2020. Studies investigating DRPs in hospitalised CKD patients published in the English language were included. Two independent reviewers extracted the data and undertook quality assessment using the Joanna Briggs Institute (JBI) tool.

RESULTS

A total of 2895 unique titles were identified; with 20 meeting the inclusion criteria. DRPs prevalence in CKD was reported between 12 and 87%. The most common DRPs included ineffective treatment, inappropriate drug choice and dosing problems. Antibiotics, H2-antihistamines and oral antidiabetics (metformin) were common drug classes involved in DRPs. Factors associated with DRPs included severity of CKD, the number of medications taken, age, length of hospital stay, and gender.

CONCLUSION

This systematic review provides evidence that DRPs are a frequent occurrence and burden for hospitalised patients with stage 1-4 CKD. Heterogeneity in study design, case detection and definitions are common, and future studies should use clearer definitions and study designs. Protocol Registration: PROSPERO: CRD42018096364.

Assessing the incidence of acidosis in patients receiving metformin with and without risk factors for lactic acidosis

BACKGROUND

Despite strong recommendations to use metformin as first-line therapy for type 2 diabetes (T2DM), its use has been suboptimal, likely due to concerns of lactic acidosis. This study compared the association of acidosis in patients with T2DM prescribed metformin with those prescribed other antihyperglycemic medications or no medications.

METHODS

This was a retrospective cohort study of patients with newly diagnosed T2DM utilizing an administrative database, which includes medical and prescription claims. Eligible patients had a diagnosis of T2DM, had continuous health plan enrollment 3 months prior to study enrollment and during the study period, and were at least 18 years of age. Mutually exclusive exposure groups were metformin only, other antihyperglycemic medications, and no medication. Acidosis cases were stratified by exposure group and risk factors for lactic acidosis (chronic obstructive pulmonary disease, hepatic dysfunction, alcohol abuse, heart failure, renal insufficiency, age of 80 years or older, and a history of acidosis). Degree of renal insufficiency was not available. Associations between exposure and acidosis were estimated, and risk factors evaluated.

RESULTS

A total of 132,780 patients met inclusion criteria: 24,936 (20%) metformin only group, 15,059 (11%) other antihyperglycemic medication group, and 92,785 (70%) no medication group. Acidosis was observed in 1.45 per 10,000 patient months (0.78 metformin, 1.59 other antihyperglycemic medication, 1.51 no medication). The unadjusted relative risk of acidosis was 0.5 for patients prescribed metformin only compared with the other exposure groups (95% confidence interval = 0.2-1.2). There was no significant difference in risk of acidosis between exposure groups, irrespective of risk factors for lactic acidosis.

CONCLUSIONS

Risk of acidosis was similar with metformin only compared with those prescribed other antihyperglycemic medications or no medication. These results support expanded use of metformin for T2DM. Additional studies are needed to understand the impact of risk factor severity on risk of lactic acidosis.

Comparison of equations for dosing of medications in renal impairment

AIM

The aim of this study is to determine the concordance among the Cockcroft-Gault, the Modification of Diet in Renal Disease and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations in hypothetical dosing of renally cleared medications.

METHODS

A total of 2163 patients prescribed at least one of the 31 renally cleared drugs under review were included in the study. Kidney function was estimated using the three equations. We compared actual prescribed dosages of the same drug with recommended dosages based on the kidney function as calculated by each of the equations and applying dosing recommendations in the Australian Medicines Handbook.

RESULTS

There was a significant difference in the kidney function values estimated from the three equations (P < 0.001). Despite the good overall agreement in renal drug dosing, we found selected but potentially important discrepancies among the doses rendered from the equations. The CKD-EPI equation non-normalized for body surface area had a greater rate of concordance with the Cockcroft-Gault equation than the Modification of Diet in Renal Disease equation for renal drug dosing.

CONCLUSIONS

There is need for a long-term multi-centre study in a diverse population to define the clinical effects of the discrepancies among the equations for drug dosing. Given the greater concordance of the non-normalized CKD-EPI equation with the Cockcroft-Gault equation for dosing, the recommendation by Kidney Health Australia and the United States National Kidney Disease Education Program that 'dosing based on either eCrCl or an eGFR with body surface area normalization removed are acceptable' seems suitable and practicable for the purpose of dosing of non-critical drugs in the primary care setting.

Disagreement in Estimates of Kidney Function for Drug Dosing in Obese Inpatients

BACKGROUND:

The Cockcroft-Gault (CG), Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations are used to estimate kidney function. However, utility has been questioned in the obese population.

OBJECTIVE:

To evaluate differences in estimates of kidney function in obese patients and implications for drug dosing.

METHODS:

This was a retrospective study of adult inpatients with a body mass index ≥30 kg/m² and stable kidney function. Patients were categorized based on creatinine clearance (CrCl): group 1-CrCl ≥ 60 mL/min and group 2-CrCl 15 to 59 mL/min. Mean estimates of kidney function and recommended doses of 8 renally eliminated medications were compared.

RESULTS:

For the 166 patients included, mean estimates using CG, MDRD, and CKD-EPI for group 1 were 87 (23) mL/min, 91 (21) mL/min, and 96 (23) mL/min, respectively. Group 2 estimates were 42 (13) mL/min, 51 (15) mL/min, and 51 (16) mL/min, respectively. MDRD and CKD-EPI estimates were significantly higher than CG in 125 (75%) and 140 (84%) patients, respectively. Dose discrepancies were most often due to higher dose recommendations using MDRD or CKD-EPI compared to CG.

CONCLUSION:

Careful consideration of the method used to estimate kidney function, the method used for developing dosing recommendations, and the risk-benefit profile is warranted when designing drug regimens in obese individuals.

Inappropriate prescribing in chronic kidney disease: A systematic review of prevalence, associated clinical outcomes and impact of interventions

INTRODUCTION

Adjusting doses of renally cleared medications and/or avoidance of nephrotoxic medications are standard clinical practices in chronic kidney disease (CKD), albeit the prevalence of inappropriate prescribing (IP) in these patients remains high. Therefore, this work sought to systematically review the prevalence of IP and compare the relative effectiveness of available interventions in reducing IP in CKD.

METHODS

Studies were identified searching PubMed/Medline, EMBASE, Cochrane Library, IPA, Web of Science, Ovid/Medline, CINAHL, and PsychINFO databases. Studies defining CKD based on laboratory markers and quantifying prevalence of IP were included.

RESULTS

Forty-nine studies from 23 countries met the inclusion criteria. An IP prevalence of 9.4%-81.1% and 13%-80.50% was reported in hospital and ambulatory settings, respectively; whereas, in long-term care facilities the prevalence ranged between 16% and 37.9%. Unsurprisingly, IP was associated with adverse drug events like increased hospital stay (Mean [SD] of 4.5 [4.8] vs 4.3 [4.5]) and high risk of mortality [40%]. Twenty-one studies reported the impact of interventions on IP; manual and computerised alerts were the main forms of interventions (n=19). The most significant reduction in IP was observed when physicians received immediate concurrent feedback from a clinical pharmacist (P<.001). Polypharmacy, comorbidities, and age were identified as predictors of IP.

CONCLUSION

IP has led to poor patient outcomes. Although pharmacist-based and computer-aided approaches have shown promising results, there is still room for improvement. Future studies should focus on developing a multifaceted intervention to address the widespread prevalence of IP and associated clinical outcomes in CKD patients.