Appropriateness of drug dose and frequency in patients with renal dysfunction in a tertiary care hospital: A cross-sectional study

Renal drug dosage adjustments and adverse drug events in patients with chronic kidney disease admitted to the hospital: a cross-sectional study

BACKGROUND

The study aimed to evaluate the agreement of prescribed drug dosages with renal dosing recommendations and describe adverse drug events (ADEs) contributing to hospital admissions of patients with chronic kidney disease (CKD).

METHODS

This cross-sectional study focused on CKD patients admitted to University Hospital Hradec Králové, with an estimated glomerular filtration rate below 60 ml/min. The necessity for renal dosage adjustments was determined using the Summary of Product Characteristics (SmPC). For medications requiring renal dosage adjustment according to SmPC, agreement between the prescribed and recommended renal dosage was assessed. ADEs were adjudicated using the OPERAM drug-related hospital admissions adjudication guide.

RESULTS

Of 375 CKD patients, 112 (30%, 95% CI 25-34) were prescribed drug dosages in disagreement with SmPC renal dosage recommendations. Perindopril, metformin, and ramipril were most frequently dosed in disagreement with SmPC. ADE-related hospital admissions occurred in 20% (95% CI 16-24) of CKD patients.

CONCLUSION

CKD patients are often prescribed medication dosages in disagreement with SmPC renal dosing recommendations. Besides explicit factors, treatment goals, feasibility of monitoring and alternative treatment must be weighed when assessing drug and dosage appropriateness. Gastrointestinal bleeding was the most frequent ADE that contributed to hospital admissions of CKD patients.

Impact of an inpatient pharmacist-driven renal dosing policy on order verification time and patient safety

Research regarding pharmacist-driven renal dosing policies has focused on cost savings or prevention of adverse drug events. However, little is known about how these policies influence time from order signature to order verification or how this efficiency may reduce the incidence of adverse outcomes. Objectives: The primary endpoint compared time from prescriber electronic order signature to pharmacist electronic order verification between pre- and post-renal dosing policy implementation. The secondary endpoint evaluated electrocardiogram QTc prolongation attributed to fluconazole accumulation in renal impairment. Methods: This retrospective analysis included adults with a creatine clearance ⩽50 mL/min who received at least two inpatient doses from a 34-medication renal dosing protocol between January-February 2020 and April-May 2020. Results: 502 patients met eligibility for the primary outcome. The pre- and post-policy cohorts shared similar baseline characteristics. Time from order signature to verification was 9 and 8 min in the pre- and post-policy groups, respectively (p = 0.0861). In all, 56 patients met inclusion criteria for the secondary outcome. The QTc interval during fluconazole increased relative to baseline in 3 of 7 (43%) pre-policy and 4 of 5 (80%) post-policy. The QTc interval exceeded 500 ms in two patients, both in the post-policy cohort. Conclusions: There was no difference in order signature to verification time. Post-policy fluconazole renal adjustment did not reduce QTc prolongation.

Evaluation of Dose Adjustment in Patients With Renal Impairment at Muhimbili National Hospital in Tanzania

Background: The burden of renal diseases is increasing in developing countries like Tanzania. Drug accumulation exposes patients with renal impairment to drug toxicity that may lead to adverse drug reactions, poor adherence to treatment, and increased healthcare costs. There is limited information on the appropriateness of dosage regimen adjustment for patients with renal impairment, particularly in developing countries such as Tanzania. This study aimed to investigate the appropriateness of drug dosing in hospitalized patients with renal impairment in Tanzania. Methods: This was a retrospective cross-sectional study. It was conducted between November 2019 and April 2020 amongst hospitalized patients at Muhimbili National Hospital. All enrolled patients had serum creatinine levels ≥1.2 mg/dL and taking at least one drug requiring dosage regimen adjustment. Creatinine clearance was calculated from patient serum creatinine using the Cockcroft-Gault equation. Drug dosing appropriateness was determined by comparing the current practice with tertiary references. The relationship between the patient's baseline characteristics and the rate of dosage regimen adjustment was determined using the X2 test. Univariate and multivariate logistic regression analysis evaluated the predictors of dosing adjustment. Results: Most of the enrolled patients, 269 (98.9%) had comorbidities. Of the medication orders included in the final analysis, 372 (27%) needed dosage regimen adjustment. Out of the 372 medication orders, not adjusted were 168 (45.2%), inappropriately adjusted 105 (28.2%), and appropriately adjusted were only 99 (26.6%). In this study, 212 (77.9%) patients received at least one drug with an incorrect dosage regimen. Females and those with level 4 renal impairment patients were more likely to have their doses appropriately adjusted compared to their counterparts. Conclusions: In this study, about three-quarters of the patients received at least one drug with an incorrect dosage regimen. Thus, appropriate measures such as the availability of national guidelines and clinical decision support systems for drug dosing adjustment in patients' renal impairment should be in place.

Drug-related problems and associated factors among patients with kidney dysfunction at a tertiary hospital in southwestern Uganda: a prospective observational study

BACKGROUND

Kidney dysfunction is a common, progressive condition that is increasingly becoming a global public health issue. Because the kidneys are the major route for drug excretion, impaired renal function can change the pharmacokinetics and pharmacodynamics of drugs that are renally excreted. Additionally, patients with kidney dysfunction often have co-morbidities and the associated use of multiple medications which increases the risk of drug-related problem (DRP) occurrence. This study aimed to determine the prevalence, types, and factors associated with DRPs in patients with kidney dysfunction.

METHOD

We conducted a prospective observational study over 3 months among hospitalized patients diagnosed with acute kidney injury or chronic kidney disease who were hospitalized in the medical ward, and patients attending the renal outpatient clinic at Mbarara Regional Referral Hospital. A total of 183 participants were enrolled through the use of a consecutive sampling technique. DRPs were classified according to the PCNE classification version 9.1. Data analysis was carried out using SPSS version 25.

RESULTS

A total of 174 patients with kidney dysfunction were included in the study with a mean ± SD age of 50.34 ± 18.13 years. A total of 219 DRPs were incurred by 138 (79.3%) study participants. The most common DRPs were 'Untreated symptoms or indication' (35.6%) followed by 'adverse event (possibly) occurring' (28.3%), and 'effect of drug treatment not optimal' (23.3%). Antimicrobials were the most involved drugs in suboptimal drug treatment (31.3%) and unnecessary drug treatment (32.1%). The study showed that length of hospital stay ≥ 5 days (AOR = 6.39, 95% CI: 1.75-23.27; p-value = 0.005) significantly increased the risk of DRP occurrence.

CONCLUSION

The current results, in agreement with previous literature, showed a high burden of DRPs among patients with kidney dysfunction. Antimicrobials were the most involved drugs in suboptimal as well as in unnecessary drug treatment. Longer hospital stay significantly increased the risk of DRPs. The high prevalence of DRPs in patients with kidney dysfunction and the potential impact on antimicrobial resistance underscores the importance of regular medication reviews and close monitoring of patients with renal dysfunction.

Drug-related problems in hospitalized patients with chronic kidney diseases and clinical pharmacist interventions

BACKGROUND

Patients with chronic kidney disease (CKD) are at high risk of drug-related problems (DRPs) because of extensive comorbidities and pharmacokinetic changes. This study aimed to identify DRPs and possible contributing factors in hospitalized patients with CKD, and evaluate the efficacy of the clinical pharmacist services in detection and intervention of DRPs in a large general hospital in Zhejiang Province, eastern China.

METHODS

With the approval of the Ethics Committee, patients with CKD admitted to the nephrology ward from January to December 2020 were enrolled in this prospective study. The clinical pharmacist identified and intervened the DRPs during hospitalization. The DRPs were classified using the Pharmaceutical Care Network Europe (PCNE) DRP classification system, and all data were statistically analyzed using Statistical Package for Social Science (SPSS) version 26.0.

RESULTS

A total of 914 patients with CKD were included, with 463 DRPs observed among 420 (45.95%) participants; the average DRP per patient was 0.51 (standard deviation [SD], 0.60) before pharmacist intervention. Treatment safety accounted for the highest proportion of problems (43.84%), followed by treatment efficacy, accounting for 43.20%. Drug selection was the most common cause of DRPs (60.26%), and antibiotics and cardiovascular agents were the most common drugs associated with DRPs (32.84% and 28.66%, respectively). A total of 85.53% of pharmaceutical intervention recommendations were followed, and 84.23% of DRPs were completely resolved after intervention by the clinical pharmacist. The proportion of patients who experienced DRPs decreased to 7.77%, with an average of 0.08 (SD 0.28) DRPs during hospitalization after pharmacist's intervention. Significant contributing factors for DRPs were CKD stage 4, number of comorbid diseases, number of prescribed medications, and hospitalization days in both the univariate and multivariate logistic regression models.

CONCLUSION

DRPs are common among hospitalized patients with CKD in China. CKD stage 4, the number of comorbidities, use of multiple prescription drugs, and extended length of hospital stay are contributing factors for DRPs. Even only one clinical nephrology pharmacist in the nephrology ward, clinical pharmacist can play an important role in facilitating the identification of DRPs in patients with CKD and assisting physicians resolve DRPs in this single center study in China.

Frequency and predictors of inappropriate medication dosages for cardiovascular disease prevention in chronic kidney disease patients: A retrospective cross-sectional study in a Malaysian primary care clinic

Patients with chronic kidney disease (CKD) are at increased risk of cardiovascular events. This study aimed to assess the frequency of inappropriate medication dosages (IMD) for cardiovascular disease prevention among patients with CKD and its predictors in an urban academic primary care clinic in Selangor, Malaysia. All patients who attended the clinic from April to June 2019 and fulfilled the inclusion criteria were included in this cross-sectional study, except for those with an estimated glomerular filtration rate (eGFR) of more than 90 ml/min, diagnosed with urinary tract infection, pregnant or were on dialysis for end stage renal disease. Their prescriptions on the electronic medical record (EMR) system were evaluated for appropriateness using the dose adjustment recommendations based on the 2018 Malaysian Clinical Practice Guidelines on management of CKD. A total of 362 medical records were included in this study. 16.6% (95% Confidence Interval [CI]: 12.9-20.8) or 60 out of 362 of the patient records analysed contained medications prescribed with inappropriate dosages. Patients with higher stages of CKD were associated with higher odds of IMD, namely CKD stage G3b (adjusted Odds Ratio [aOR] 10.41; 95% CI: 2.31-46.88) and CKD stage 4-5 (aOR 15.76; 95% CI: 3.22-77.28). Other predictors of IMD were diagnosis of diabetes mellitus (aOR 6.40; 95% CI: 2.15-19.01), number of prescribed medications of 5 or more (aOR 4.69; 95% CI: 1.55-14.20), and eGFR reduction of more than 25% over one year (aOR 2.82; 95% CI: 1.41-5.65). Within the limitations of this study, we conclude that the occurrence of IMD for CVD prevention was low in CKD patients in this primary care clinic. Medications with inappropriate dosages identified in this study include simvastatin, fenofibrate, hydrochlorothiazide, spironolactone, metformin, gliclazide, sitagliptin, dapagliflozin and empagliflozin. Clinicians should consider the predictors of inappropriate medication dosages listed above when prescribing to patients with CKD to reduce the risk of medications-related toxicities and adverse effects. Limitations of this study should be considered when interpreting the findings presented.

Assessment of alteration in antiviral plasma concentration across dialysis days: computational and analytical study

Aim: Protein-bound uremic toxins (PBUTs) may displace drugs from the plasma proteins and render them more liable to clearance. This study aims to investigate the possible interplay between PBUTs and directly acting antivirals (DAAs). Methods: PBUT plasma protein binding was compared to those of paritaprevir (PRT), ombitasivir (OMB) and ritonavir (RTV) in silico to assess the possible competitive displacement. The three drugs were LC-MS/MS determined in seven patients across dialysis and non-dialysis days and results were compared. Results & conclusion: Results showed that the PBUT exhibited a lower binding than DAA reducing the liability of their competitive displacement. This was echoed by an unaltered plasma concentration across dialysis days. Results may indicate that PBUT accumulation may have limited effect on disposition of DAA.

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.

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.

Design, development, and deployment of an indication- and kidney function-based decision support tool to optimize treatment and reduce medication dosing errors

Delivering clinical decision support (CDS) at the point of care has long been considered a major advantage of computerized physician order entry (CPOE). Despite the widespread implementation of CPOE, medication ordering errors and associated adverse events still occur at an unacceptable level. Previous attempts at indication- and kidney function-based dosing have mostly employed intrusive CDS, including interruptive alerts with poor usability. This descriptive work describes the design, development, and deployment of the Adult Dosing Methodology (ADM) module, a novel CDS tool that provides indication- and kidney-based dosing at the time of order entry. Inclusion of several antimicrobials in the initial set of medications allowed for the additional goal of optimizing therapy duration for appropriate antimicrobial stewardship. The CDS aims to decrease order entry errors and burden on providers by offering automatic dose and frequency recommendations, integration within the native electronic health record, and reasonable knowledge maintenance requirements. Following implementation, early utilization demonstrated high acceptance of automated recommendations, with up to 96% of provided automated recommendations accepted by users.

Assessment of the Appropriateness of Ceftazidime Use in a Tertiary Teaching Hospital, Northern Ethiopia

Background

Ceftazidime is nowadays one of the most commonly used antibiotics due to its high antibacterial potency, wide spectrum of activity, and low potential for toxicity. However, the global trend shows huge misuse of ceftazidime.

Objective

This study was conducted to assess the appropriateness of ceftazidime use and to identify areas of intervention to prevent inappropriate use in different wards of Ayder Compressive Specialized Hospital, a tertiary teaching Hospital, Mekelle-Ethiopia.

Methods

A facility-based prospective cross-sectional study design was steered on 327 patients who received ceftazidime during their hospitalization in the selected wards from February 1 to April 30, 2019.

Results

In the assessment of the appropriateness of ceftazidime use, 2,084 (70.8%) were appropriate. Appropriateness of indication was 295 (90.2%), the effectiveness of ceftazidime use was 221 (67.6%), correct dose of ceftazidime use was 264 (80.4%), and the correct frequency of ceftazidime use was 230 (70.3%). Its use was empiric in 275 participants (84.1%) and specific in 52 (15.9%) participants. The most common indication for ceftazidime use was uncomplicated pneumonia, at 112 (34.3%). One hundred and seventy-one (52.3%) participants had intervention to prevent inappropriate use of ceftazidime. Changing the drug combination (96, 29.4%), increasing the dose (13, 4%), decreasing the dose (21, 6.4%), holding the (21, 6.4%), and discontinuation of ceftazidime (20, 6.1%) were among the interventions.

Conclusion

This study revealed that more than one-fourth of the ceftazidime use was inappropriate. This may lead to the emergence of resistant pathogens which in turn lead to treatment failure and increased the cost of therapy. Therefore, adherence to current evidence-based guidelines and initiating antimicrobial stewardship are recommended.

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.

Pattern and Predictors of Medication Dosing Errors in Chronic Kidney Disease Patients in Pakistan: A Single Center Retrospective Analysis

BACKGROUND

Chronic kidney disease (CKD) alters the pharmacokinetic and pharmacodynamic response of various drugs and increases the risk of toxicity. The data regarding the pattern and predictors of medication dosing errors is scare from the developing countries. Therefore, the present study was conducted to assess the pattern and predictors of medication dosing errors in CKD patients in a tertiary care setting in Pakistan.

METHODS

A retrospective study design was employed and medical charts of all those CKD patients who had an eGFR ≤60ml/min/1.73m2, hospitalization ≥24 hours, and admitted in the nephrology unit during January 2013 to December 2014 were assessed. Descriptive statistics and the logistic regression analysis were done using IBM SPSS version 20.

RESULTS

In total, 205 medical charts were assessed. The mean age of patients was 38.64 (±16.82) years. Overall, 1534 drugs were prescribed to CKD patients, of which, nearly 34.0% drugs required dose adjustment. Among those drugs, only 41.8% were properly adjusted, and the remaining 58.2% were unadjusted. The logistic regression analysis revealed that the medication dosing errors were significantly associated with the CKD stages, i.e. stage 4 (OR 0.054; 95% CI [0.017-0.177]; p <0.001) and stage 5 (OR 0.098; 95% CI [0.040-0.241]; p <0.001), the number of prescribed medicines ≥ 5 (OR 0.306; 95% CI [0.133-0.704]; p 0.005), and the presence of a comorbidity (OR 0.455; 95% CI [0.226-0.916]; p 0.027) such as the hypertension (OR 0.453; 95% CI [0.231-0.887]; p 0.021).

CONCLUSIONS

It is concluded that more than half drugs prescribed to CKD patients requiring dose adjustment were unadjusted. The predictors of medication dosing errors were the severe-to-end stages of chronic kidney disease, the presence of a comorbidity such as hypertension, and a higher number of prescribed medicines. Therefore, attention should be paid to these risk factors.

Adherence with renal dosing recommendations in outpatients undergoing haemodialysis

WHAT IS KNOWN AND OBJECTIVE

Adjustment of drug dosage in patients with end-stage renal disease prevents serious adverse effects, which occur due to the accumulation of drugs or other toxic metabolites. Nevertheless, dosing errors occur most commonly among patients with end-stage renal disease. The aim of this study was to assess the quality of care for end-stage renal disease outpatients using their renal dosing adjustment status.

METHODS

A cross-sectional study was performed using the data collected from 43 South Korean medical institutions via questionnaires. A total of 2428 patients on haemodialysis, who were at least 18 years of age, were included. Among these patients, the study population was confined to patients who were taking medications and required renal dosing adjustments from three therapeutic classes: antihypertensives, antihyperglycaemics and lipid-modifying agents. The study population (n = 828) was prescribed a total of 1097 drug orders for the target drugs. Determination of appropriate dosage adjustment was based on GFR (glomerular filtration rate) using the Modification of Diet in Renal Disease revised 4-variable equation. The primary outcome was non-adherence to drug dosing requirements for end-stage renal disease patients with consideration to their renal function.

RESULTS AND DISCUSSION

Among the study population (n = 828), 469 haemodialysis patients were identified as having drug orders that were adherent to renal dosing recommendations. There were significant differences between the patient groups who received recommendation-adherent and non-adherent drug orders in the characteristics of the medical institutions they visited, causes of chronic renal failure and prevalence of concurrent diabetes mellitus. The primary factor of non-adherence to renal dosing adjustment recommendations was characteristics of medical institutions. Compared to tertiary hospitals, secondary hospitals and primary care clinics were 1·16 and 1·22 times, respectively, more non-adherent in accordance with the multivariate analysis (OR: 1.16, 95% CI: 1.02-1.20, OR: 1.22, 95% CI: 1·00-1·36, respectively).

WHAT IS NEW AND CONCLUSIONS

Dosing error is one of the most common problems among patients with renal failure. To decrease the dosing errors, an improvement needs to be made in medical institutions. This can be accomplished by implementing the clinical decision support systems that educate physicians on appropriate renal dosing and help them prescribe appropriate drug dosages.

Use of renal risk drugs in patients with renal impairment

BACKGROUND

Renal impairment often goes unrecognised until the most advanced stages. Patients with renal impairment use a variety of drugs and the pharmacokinetics and drug effects are prone to change.

OBJECTIVE

Describe drug related problems in a population of patients with renal impairment, investigate possible risk factors, and investigate whether the clinical pharmacist can propose relevant measures to solve the problems.

SETTING

The internal medicine department at Innlandet Hospital Trust Gjøvik, Norway.

METHOD

A prospective study enrolling patients (≥18 years) with moderate and severe renal impairment, i.e. with glomerular filtration rate of 30-59 and 15-29 ml/min/1.73 m(2), respectively, and using at least one drug. The clinical pharmacist reviewed the patients' drug regimen with focus on drug related problems, related to renal function. Problems identified were discussed with the multidisciplinary team, or directly with the physician.

MAIN OUTCOME MEASURE

The number of drug related problems.

RESULTS

The results are based on data from 79 patients, 21 with severe and 58 with moderate renal impairment. Most patients, 92.4 %, used 5 or more drugs; in average 10.2 (range 2-27). In total, 88 drug related problems were identified in 49 patients, i.e. in 62 %. The most frequently occurring problems were incorrect dose (45.5 %) and inappropriate drug (41.0 %). There was a significant correlation between both the degree of renal impairment and the number of drugs, and the number of drug related problems. The acceptance rate of the clinical pharmacist's interventions was 95.7 %. The drugs most frequently associated with drug related problems were metformin, benzylpenicillin and furosemide.

CONCLUSION

Drug related problems often occur in patients with renal impairment. Incorrect drug dose and inappropriate drug choice according to the patients' renal function were the most common problems. Patients with the most complex drug treatment, i.e. with increasing degree of renal impairment and increasing number of drugs, are at greater risk of drug related problems. The high acceptance rate for the pharmacist's interventions supports the inclusion of a clinical pharmacist in the multidisciplinary treatment team to increase awareness and optimisation of the drug treatment in this patient group.

Understanding physicians' behavior toward alerts about nephrotoxic medications in outpatients: a cross-sectional analysis

BACKGROUND

Although most outpatients are relatively healthy, many have chronic renal insufficiency, and high override rates for suggestions on renal dosing have been observed. To better understand the override of renal dosing alerts in an outpatient setting, we conducted a study to evaluate which patients were more frequently prescribed contraindicated medications, to assess providers' responses to suggestions, and to examine the drugs involved and the reasons for overrides.

METHODS

We obtained data on renal alert overrides and the coded reasons for overrides cited by providers at the time of prescription from outpatient clinics and ambulatory hospital-based practices at a large academic health care center over a period of 3 years, from January 2009 to December 2011. For detailed chart review, a group of 6 trained clinicians developed the appropriateness criteria with excellent inter-rater reliability (κ=0.93). We stratified providers by override frequency and then drew samples from the high- and low-frequency groups. We measured the rate of total overrides, rate of appropriate overrides, medications overridden, and the reason(s) for override.

RESULTS

A total of 4120 renal alerts were triggered by 584 prescribers in the study period, among which 78.2% (3,221) were overridden. Almost half of the alerts were triggered by 40 providers and one-third was triggered by high-frequency overriders. The appropriateness rates were fairly similar, at 28.4% and 31.6% for high- and low-frequency overriders, respectively. Metformin, glyburide, hydrochlorothiazide, and nitrofurantoin were the most common drugs overridden. Physicians' appropriateness rates were higher than the rates for nurse practitioners (32.9% vs. 22.1%). Physicians with low frequency override rates had higher levels of appropriateness for metformin than the high frequency overriders (P=0.005).

CONCLUSION

A small number of providers accounted for a large fraction of overrides, as was the case with a small number of drugs. These data suggest that a focused intervention targeting primarily these providers and medications has the potential to improve medication safety.

Ceftriaxone-induced acute encephalopathy in a peritoneal dialysis patient

Encephalopathy is a rare side effect of third and fourth generation cephalosporins. Renal failure and preexisting neurological disease are notable risk factors. Recognition is important as discontinuing the offending agent usually resolves symptoms. We present a case of acute encephalopathy in a patient with end stage renal disease (ESRD) treated with peritoneal dialysis (PD) who received intravenous ceftriaxone for peritonitis. This case illustrates the potential severe neurologic effects of cephalosporins, which are recommended by international guidelines as first-line antimicrobial therapy for spontaneous bacterial peritonitis.

Personalized therapeutics for levofloxacin: a focus on pharmacokinetic concerns

Background

Personalized medicine should be encouraged because patients are complex, and this complexity results from biological, medical (eg, demographics, genetics, polypharmacy, and multimorbidities), socioeconomic, and cultural factors. Levofloxacin (LVX) is a broad-spectrum fluoroquinolone antibiotic. Awareness of personalized therapeutics for LVX seems to be poor in clinical practice, and is reflected in prescribing patterns. Pharmacokinetic–pharmacodynamic studies have raised concerns about suboptimal patient outcomes with the use of LVX for some Gram-negative infections. Meanwhile, new findings in LVX therapeutics have only been sporadically reported in recent years. Therefore, an updated review on personalized LVX treatment with a focus on pharmacokinetic concerns is necessary.

Methods

Relevant literature was identified by performing a PubMed search covering the period from January 1993 to December 2013. We included studies describing dosage adjustment and factors determining LVX pharmacokinetics, or pharmacokinetic–pharmacodynamic studies exploring how best to prevent the emergence of resistance to LVX. The full text of each included article was critically reviewed, and data interpretation was performed.

Results

In addition to limiting the use of fluoroquinolones, measures such as reducing the breakpoints for antimicrobial susceptibility testing, choice of high-dose short-course of once-daily LVX regimen, and tailoring LVX dose in special patient populations help to achieve the validated pharmacokinetic–pharmacodynamic target and combat the increasing LVX resistance. Obese individuals with normal renal function cleared LVX more efficiently than normal-weight individuals. Compared with the scenario in healthy subjects, standard 2-hour spacing of calcium formulations and oral LVX was insufficient to prevent a chelation interaction in cystic fibrosis patients. Inconsistent conclusions were derived from studies of the influence of sex on the pharmacokinetics of LVX, which might be associated with sample size and administration route. Children younger than 5 years cleared LVX nearly twice as fast as adults. Patients in intensive care receiving LVX therapy showed significant pharmacokinetic differences compared with healthy subjects. Creatinine clearance explained most of the population variance in the plasma clearance of LVX. Switching from intravenous to oral delivery of LVX had economic benefits. Addition of tamsulosin to the LVX regimen was beneficial for patients with bacterial prostatitis because tamsulosin could increase the maximal concentration of LVX in prostatic tissue. Coadministration of multivalent cation-containing drugs and LVX should be avoided. For patients receiving warfarin and LVX concomitantly, caution is needed regarding potential changes in the international normalized ratio; however, it is unnecessary to seek alternatives to LVX for the sake of avoiding drug interaction with warfarin. It is unnecessary to proactively reduce the dose of cyclosporin or tacrolimus when comedicated with LVX. Transporters such as organic anion-transporting polypeptide 1A2, P-glycoprotein, human organic cation transporter 1, and multidrug and toxin extrusion protein 1 are involved in the pharmacokinetics of LVX.

Conclusion

Personalized LVX therapeutics are necessary for the sake of better safety, clinical success, and avoidance of resistance. New findings regarding individual dosing of LVX in special patient populations and active transport mechanisms in vivo are opening up new horizons in clinical practice.