Renally Dosed Cefepime Leading to Cefepime-Induced Neurotoxicity: A Case Report

Cefepime is a broad-spectrum fourth-generation cephalosporin with activity against both gram-positive and gram-negative bacteria, including Pseudomonas aeruginosa. Cefepime is most commonly used for urinary tract infections, soft tissue infections, and febrile neutropenia. Up to 15% of ICU patients on cefepime may experience cefepime-induced neurotoxicity (CIN), with risk factors including renal dysfunction, excessive dosage, elevated serum cefepime concentrations, and history of prior brain injury. The adverse effects of CIN, including encephalopathy, seizures, and coma can be resolved with drug cessation, antiepileptics, or hemodialysis. Here, we present the case of CIN in a 59-year-old female patient with long-term cefepime antibiotic prescription for Pseudomonas bacteremia and endocarditis with multiple risk factors for reduced renal function. We discuss the relevant risk factors and preventive measures that may have prevented her from developing CIN, as well as the importance of early recognition and prevention of CIN in patient care.

Delayed Diagnosis of an Invisible Seizure: Cefepime-Induced Non-convulsive Status Epilepticus

Cefepime-induced non-convulsive status epilepticus (NCSE) is a recognized adverse event of cefepime. Risk factors for this adverse event include older age, underlying renal dysfunction, previous brain injury, diabetes, and severe infection. We present a case of a 79-year-old woman with no prior seizure history, who was admitted for Pseudomonas aeruginosa surgical wound infection for which she was on cefepime. She developed acute encephalopathy with associated, occasional, right-sided myoclonic facial twitches 11 days into her admission. Electroencephalogram (EEG) confirmed NCSE as evident by epileptiform activity described as generalized periodic discharges with predominantly triphasic morphology. Cefepime was substituted with piperacillin-tazobactam> 24 hours after symptom onset. NCSE completely resolved two days after the discontinuation of cefepime. This case highlights the fact that NCSE can occur even when precautions such as renal dosing of cefepime are observed. Clinicians need to have a high index of suspicion for the condition when taking care of at-risk patients on cefepime, as delayed diagnosis correlates with potentially fatal outcomes.

Deviant Dosing: A Post hoc Analysis of Pharmacist Characteristics Related to Renal Dosing Decisions

BACKGROUND

A recent study demonstrated that pharmacists presented with multiple estimating equations deviated from recommended dosing guidance more often than pharmacists who were presented with a single estimate on clinical vignettes.

OBJECTIVES

To identify characteristics associated with an increased tendency to deviate from approved recommendations.

METHODS

Participant data were split into 2 cohorts: pharmacists who chose a dose that was inconsistent with dosing recommendations on at least 1 of the 4 vignettes and pharmacists who did not deviate on a single case. Bivariate analysis of demographic- and practice-related variables were conducted between groups using the χ², Mann-Whitney U, or Student t-test for nominal, ordinal, and continuous variables, respectively. Statistically different covariates between groups (P < 0.05) were assessed using multivariable linear regression.

RESULTS

Survey data from 154 inpatient pharmacists, 71 of whom deviated on at least 1 clinical vignette, were analyzed. On univariate analysis, deviator pharmacists were more likely to have completed postgraduate residency training (68% vs 41%; P < 0.05) and board certification (39% vs 20%; P < 0.05). Deviator pharmacists were also more likely to have been presented with multiple renal estimates as opposed to a single estimate and had differing renal dosing practices at baseline (P < 0.05). Following multivariable regression, residency training, mismatched baseline renal practices, and multiple renal estimates remained independent predictors (P < 0.05) of dosing deviation.

CONCLUSION AND RELEVANCE

Higher clinical training, practice variation, and multiple renal estimates may affect renal dosing practices. Prospective, statistically powered studies are needed to verify these hypotheses.

Discordance of renal drug dosing using estimated creatinine clearance and measured urine creatinine clearance in hospitalized adults: A retrospective cohort study

Background

Assessment of kidney function is fundamental to optimize drug dosing. The Cockcroft-Gault (CG) equation is widely used but has questionable validity for females, changing renal function, and the critical ill. Eight-hour urine collections (U_8h) offer direct measurement of creatinine clearance (CrCl) but lack the data for drug dosing. The primary objective of this study was to determine if there was a difference in renal drug dosing based on the estimation of CG CrCl (CrCl_CG) versus 8-h CrCl (CrCl_8h).

Methods

This was an observational, retrospective cohort study of adult patients admitted between March 2018 and September 2018 with a collection U_8h during hospitalization. The primary outcome was discordance of renal drug dosing defined as the percentage of U_8h for which at least one different active medication CrCl dosing cutoff would result using the CrCl_CG versus CrCl_8h. The secondary outcomes were correlation between CrCl_CG and CrCl_8h and percentage of CrCl_CG values outside ± 20% of the CrCl_8h.

Results

One hundred collections drawn from 85 unique patients (50.6% male, median age 55 [41-70] years, intensive care unit 88%) were included in the analysis. Median serum creatinine was 0.76 (0.52-1.06) mg/dL and blood urea nitrogen was 20 (14-28) mg/dL at time of collection_8h. Median CrCl_8h was 86.2 (43.5-140.3) mL/min versus 99.7 (56.5-166.9) mL/min CrCl_CG(P < 0.001) and discordance was 25%. The correlation between CrCl_8h and CrCl_CG was 0.76 (P < 0.001). Only 31% of CrCl_CG values were within ± 20% of the CrCl_8h value.

Conclusion

We found 25% discordance for drug dosing between CrCl_8h and CrCl_CG. Further studies are needed to determine the impact on clinical outcomes.

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.

Evaluation of a Pharmacy-Managed Pharmacokinetic Dosing Program

PURPOSE

The objective of this study was to determine the impact of a pharmacy-managed pharmacokinetic dosing program on appropriate dosing of famotidine, enoxaparin, and ketorolac.

METHODS

A large community teaching hospital implemented a pharmacy-managed pharmacokinetic dosing program for famotidine, enoxaparin, and ketorolac. Subjects were included if they received famotidine and had a creatinine clearance (CrCl) of <50 mL/min; received therapeutic enoxaparin and had a CrCl of <30 mL/min; or received ketorolac and had a CrCl <30 mL/min, age > 65 years or weight <50 kg.

RESULTS

One hundred and forty-six patients were included in the preimplementation group (famotidine [n = 50], enoxaparin [n = 46], and ketorolac [n = 50]) and 143 patients were included in the postimplementation group (famotidine [n = 50], enoxaparin [n = 43], and ketorolac [n = 50]). In all, 66% of patients were dosed appropriately in the preimplementation group (famotidine 28%, enoxaparin 85%, and ketorolac 86%) compared to 94% in the postimplementation group (famotidine 92%, enoxaparin 95%, and ketorolac 94%), P < .001.

CONCLUSION

Implementation of a pharmacy-managed pharmacokinetic dosing program significantly improved appropriate dosing of famotidine, enoxaparin, and ketorolac. These findings could justify expansion of pharmacist autonomy through institution-approved, pharmacy-managed programs for other medications to improve appropriate dosing. Analyses specifically evaluating patient-oriented or financial outcomes may provide additional support for expansion.