Suspected piperacillin-tazobactam induced nephrotoxicity in the pediatric oncology population

Relationship between nephrotoxicity and area under the concentration-time curve of vancomycin in critically ill patients: a multicenter retrospective study

We aimed to assess the frequency of acute kidney injury (AKI) in different areas under the concentration-time curve (AUC) values of vancomycin (VAN) using a two-point blood collection method, allowing for accurate AUC assessment in critically ill patients. This multicenter retrospective observational study was conducted in eight hospitals. We retrospectively analyzed the data of patients who had received VAN in an intensive care unit (ICU) between January 2020 and December 2022. The primary outcome was the incidence of AKI. Patients were classified into three groups according to the AUC24-48h at the initial therapeutic drug monitoring (TDM) as follows: <500, 500-600, and ≥600 µg·h/mL. The AUC24-48h values were calculated using the Bayesian estimation software Practical AUC-guided TDM. Among 146 patients [median age (interquartile range), 67 (56-78) years; 39% women], the AUC24-48h <500 µg·h/mL had an AKI rate of 6.5% (7/107), the AUC24-48h 500-600 µg·h/mL had an AKI rate of 28.0% (7/25), and the AUC24-48h ≥600 µg·h/mL had an AKI rate of 42.9% (6/14). In multivariate Cox proportional hazard analysis, the AUC24-48h 500-600 µg·h/mL [hazard ratio 5.4, 95% confidence interval (CI) 1.64-17.63] and the AUC24-48h ≥600 μg·h/mL (hazard ratio 7.0, 95% CI 2.31-21.18) significantly correlated with a higher incidence of AKI compared with the AUC24-48h <500 μg·h/mL. In conclusion, we identified an association between AUC on day 2 and the risk of AKI in ICU patients, suggesting that not only AUCs above 600 µg·h/mL but also those between 500 and 600 µg·h/mL pose a risk for AKI.

IMPORTANCE

Vancomycin (VAN) is a glycopeptide antibiotic and one of the most commonly used antibiotics for severe infections caused by methicillin-resistant Staphylococcus aureus. However, higher VAN concentrations have been associated with an increased risk of acute kidney injury (AKI). Herein, we aimed to assess the frequency of AKI in different areas under the concentration-time curve (AUC) values of VAN using a two-point blood collection method, allowing for accurate AUC assessment in critically ill patients. We identified an association between AUC on day 2 and the risk of AKI in intensive care unit patients, suggesting that not only AUCs above 600 µg·h/mL but also those between 500 and 600 µg·h/mL pose a risk for AKI. Therefore, individualized dosing is feasible, with pharmacists being able to optimize VAN doses to attain appropriate targets.

[Potential Nephrotoxicity of Combination of Vancomycin and Piperacillin-Tazobactam: Recommendations from the AG ABS of the DGPI supported by experts of the GPN]

The combination of vancomycin and piperacillin/tazobactam (V+P/T) is used for empirical antibiotic treatment of severe infections, especially in immunocompromised patients and those colonized with multidrug-resistant bacteria. Nephrotoxicity is a frequently observed adverse effect of vancomycin. Its risk can be reduced by therapeutic drug monitoring and adjusted dosing. Piperacillin/tazobactam (P/T) rarely causes interstitial nephritis. The results of retrospective cohort studies in children predominantly show a low, clinically irrelevant, additive nephrotoxicity (defined as an increase in creatinine in the serum) of both substances. Due to the limitations of the existing publications, the ABS working group of the DGPI and experts of the GPN do not recommend against the use of P/T plus vancomycin. Preclinical studies and a prospective study with adult patients, which evaluated different renal function tests as well as clinical outcomes, do not support previous findings of additive nephrotoxicity. Time-restricted use of V+P/T can minimize exposure and the potential risk of nephrotoxicity. Local guidelines, developed in collaboration with the antibiotic stewardship team, should define the indications for empirical and targeted use of P/T and V+P/T. When using combination therapy with V+P/T, kidney function should be monitored through clinical parameters (volume status, balancing, blood pressure) as well as additional laboratory tests such as serum creatinine and cystatin C.

Impact of Antimicrobial Drug-Drug Interactions on Acute Kidney Injury after Allogeneic Hematopoietic Cell Transplantation

Acute kidney injury (AKI) is one of the major complications after allogeneic hematopoietic stem cell transplantation (allo-HSCT). The use of multiple antimicrobials is one of the major causes of post-transplantation AKI, owing to the potential nephrotoxicity of each agent and of drug-drug interactions (DDIs). No satisfactory reports on DDIs the field of allo-HSCT have been published. We performed a retrospective analysis to compare the incidence of AKI within 100 days post-transplantation. A total of 465 allo-HSCTs in 416 patients were analyzed, and the cumulative incidence of AKI was 40.0%. AKI was associated with significantly reduced overall survival (hazard ratio [HR], 2.66; 95% confidence interval [CI] 1.95 to 3.55; P < .01) and increased transplantation-related mortality (HR, 4.77, 95% CI, 2.90 to 7.88; P < .01). A higher incidence of AKI was significantly associated with the use of ciprofloxacin, cefepime, tazobactam/piperacillin, meropenem, vancomycin, liposomal amphotericin B, ganciclovir, and foscarnet. Among these drugs, combinations of vancomycin plus tazobactam/piperacillin (HR, 2.23; P = .09 for interaction), ganciclovir plus cefepime (HR, 5.93; P = .04), and ganciclovir plus meropenem (HR, 2.63; P = .12) synergistically increased the risk of AKI, whereas combinations involving teicoplanin did not. This is the first report dealing with DDIs after allo-HSCT, indicating that such combinations should be avoided to preserve renal function and reduce AKI-related morbidity and mortality.

Piperacillin–Tazobactam Plus Vancomycin-Associated Acute Kidney Injury in Adults: Can Teicoplanin or Other Antipseudomonal Beta-Lactams Be Remedies?

Numerous observational studies and meta-analyses have suggested that combination therapy consisting of piperacillin–tazobactam (TZP) and vancomycin (VAN) augments acute kidney injury (AKI) risk when compared to viable alternatives, such as cefepime–vancomycin (FEP–VAN) and meropenem–VAN. However, the exact pathophysiological mechanisms of this phenomenon are still unclear. One major limitation of the existing studies is the utilization of serum creatinine to quantify AKI since serum creatinine is not a sufficiently sensitive and specific biomarker to truly define the causal relationship between TZP–VAN exposure and nephrotoxicity. Even so, some preventive measures can be taken to reduce the risk of AKI when TZP–VAN is preferred. These measures include limiting the administration of TZP–VAN to 72 h, choosing FEP–VAN in place of TZP–VAN in appropriate cases, monitoring the VAN area under the curve level rather than the VAN trough level, avoiding exposure to other nephrotoxic agents, and minimizing the prescription of TZP–VAN for patients with a high risk of AKI. More data are needed to comment on the beneficial impact of the extended-infusion regimen of TZP on nephrotoxicity. Additionally, TZP and teicoplanin can be reasonable alternatives to TZP–VAN for the purpose of lowering AKI risk. However, the data are scarce to advocate this practice convincingly.

Incidence and Risk Factors for Acute Kidney Injury in Hospitalized Children Receiving Piperacillin-Tazobactam

OBJECTIVE

Drug-induced kidney injury contributes to morbidity and mortality in hospitalized children. Antibiotics such as TZP have been implicated in the development of acute kidney injury (AKI) in adults; however, data are limited in children. The purpose of this study was to determine the incidence of AKI in hospitalized children receiving TZP.

METHODS

This was a retrospective cohort study of hospitalized children between 2 months and 19 years of age who received TZP for at least 48 hours. Acute kidney injury was defined as a 50% increase from the initial serum creatinine (SCr) prior to TZP initiation. Serum creatinine values were adjusted for fluid balance using a validated approach. Severity of AKI was characterized using the Pediatric Risk, Injury, Failure, Loss, End-Stage Renal Disease (pRIFLE) criteria. Descriptive and inferential statistics were used to describe the incidence and risk factors of AKI, with an alpha = 0.05.

RESULTS

A total of 65 subjects were included. Twenty-five (38.5%) required PICU admission. The incidence of AKI was 7.7% (n = 5) using adjusted SCr (13.37 cases/1000 patient-days). According to pRIFLE, 6.15% (n = 4) subjects met criteria for Risk (n = 3) or Injury (n = 1), and none developed Failure, Loss, or End-Stage (10.70 cases/1000 patient-days for Risk and Injury categories). No risk factors were identified. Hospital length of stay was longer in subjects who experienced AKI compared with those who did not (p = 0.04).

CONCLUSIONS

The incidence of AKI in hospitalized children exposed to TZP was low. In those who did develop AKI, peak SCr occurred approximately 1 week after TZP initiation.

Comparative incidence of acute kidney injury in patients on vancomycin therapy in combination with cefepime, piperacillin-tazobactam or meropenem

Recent studies have shown that the incidence of nephrotoxicity increases when vancomycin is combined with a beta-lactam antibiotic. The objective of this study was to compare the incidence of acute kidney injury (AKI) in adult patients who received vancomycin with either piperacillin-tazobactam (VPT), cefepime (VC), or meropenem (VM). This was a single center retrospective chart review. Patients were included if they were 18 years or older, received 48 hours of combination therapy and antibiotics were started within 24 hours of each other. Exclusion criteria were receiving more than one combination of antibiotics, serum creatinine > 1.2 mg/dL, AKI at the time of inclusion, or any form of renal replacement therapy. Two hundred patients met inclusion criteria. A total of 27 (13%) patients experienced AKI. The incidence of AKI was 21.6%, 9%, and 7.4% in the VPT, VC and VM groups, respectively. A patient who received VPT was 5 times more likely to develop AKI when compared to a patient who received VC (adjusted OR 5.09 95% CI (1.51-17.08), p = 0.008) and 7 times more likely to develop AKI when compared to VM (adjusted OR 7.03 95% CI (1.97-28.08), p = 0.002). This study found a statistically significant difference in the incidence of AKI in patient receiving VPT when compared to VC or VM. This finding supports the need for careful monitoring of renal function in patients receiving VPT therapy and routine evaluation for de-escalation of antimicrobial therapy.

Nephrotoxicity from Vancomycin Combined with Piperacillin-Tazobactam: A Comprehensive Review

BACKGROUND

Recent studies have identified the combination of vancomycin with piperacillin-tazobactam (VPT) to be associated with increased nephrotoxicity. Multiple, large cohort studies have found this widely used combination to have a higher risk of nephrotoxicity than other regimens in a variety of populations.

SUMMARY

This review summarizes the epidemiology and clinical features of VPT-associated acute kidney injury (AKI). Potential mechanisms involved in the pathogenesis of this phenomenon are also discussed. Key Message: VPT-associated nephrotoxicity is a recently recognized clinical entity. Clinical strategies to minimize the risk of toxicity in this setting include antimicrobial stewardship, monitoring of kidney function, and emerging data supporting the potential role for novel biomarkers in predicting and managing AKI.

Reversible Impaired Methotrexate Clearance After Platinum-Based Chemotherapy for Osteosarcoma

The authors present a case of an 18-year-old man with metastasized osteosarcoma, admitted for methotrexate (MTX) treatment combined with cisplatin and doxorubicin. During the first cycle, severe MTX toxicity was observed with increased MTX serum levels and delayed MTX clearance requiring rescue treatment with intensified leucovorin. In the following cycles, cisplatin and doxorubicin were discontinued, and MTX dose was reduced. The elimination half-life slowly improved over the following cycles suggesting a reversible cause responsible for reduced MTX clearance and toxicity during the first cycle. Cisplatin is well-known for its nephrotoxic effects and can induce reversible tubular injury. Previous treatment with cisplatin may well have been responsible for decreased MTX clearance, and combination treatment should be used with adequate monitoring of MTX levels. Other factors that may have contributed, such as urine alkalization, gene polymorphisms, and other drug-drug interactions are discussed.

The association of acute kidney injury with the concomitant use of vancomycin and piperacillin/tazobactam in children: A systematic review and meta-analysis

Concomitant use of vancomycin plus piperacillin/tazobactam (TZP) has been associated with increased risk of acute kidney injury (AKI) in hospitalized adults. In this systematic review and meta-analysis, we searched PubMed and EMBASE for pediatric studies examining this hypothesis, with reference to vancomycin monotherapy or in combination with another beta-lactam antibiotic. Out of 1381 non-duplicate studies, 10 met our inclusion criteria. We performed a random effects meta-analysis, based on crude odds ratios, and we accounted for both quality of included studies and publication bias. In primary analysis, concomitant vancomycin and TZP use yielded a statistically significant association with the development of AKI. More specifically, children with AKI had higher odds to have been exposed to vancomycin plus TZP, in comparison with vancomycin monotherapy (OR 8.15; 95% CI: 3.49-18.99), or vancomycin plus any other beta-lactam antibiotic (OR 3.48; 95% CI: 2.71-4.46). Based on the results of the Newcastle Ottawa Scale quality assessment, a secondary analysis including only higher quality studies (6 out of 10 studies) yielded again higher odds of exposure to vancomycin plus TZP, compared to vancomycin plus another beta-lactam antibiotic (OR 3.76; 95% CI: 2.56-5.51). Notably, even after controlling for possible publication bias our results remained statistically significant (OR 3.09; 95% CI: 2.30-4.14). In conclusion, the concomitant use of vancomycin and TZP could be associated with AKI development and the clinical significance of this potential association needs to be studied further in the pediatric population.

Incidence of Nephrotoxicity Among Pediatric Patients Receiving Vancomycin With Either Piperacillin-Tazobactam or Cefepime: A Cohort Study

BACKGROUND

Recent studies in adults have found an incidence of acute kidney injury (AKI) in patients treated with a combination of vancomycin and piperacillin-tazobactam (TZP) that is greater than that expected with either medication alone. The purpose of this study was to determine whether combination therapy with vancomycin and TZP is associated with an incidence of AKI in pediatric patients higher than that in those on combination therapy with vancomycin and cefepime.

METHODS

We performed a retrospective single-center matched-cohort study of pediatric patients who received vancomycin in combination with TZP or cefepime between January 2015 and June 2016. The patients were matched according to chronic disease, age, sex, and number of concomitant nephrotoxic medications at the time of combination antibiotic therapy. The primary outcome was incidence of AKI. Secondary outcomes included differences between groups in time to AKI, resolution of AKI, and effect of vancomycin trough levels on the incidence of nephrotoxicity. Conditional logistic regression was used to compare categorical and continuous variables between treatment groups. Conditional Poisson regression was used to assess the association between AKI and treatment groups. Stratified log-rank tests and Cox proportional hazards models with shared frailty were used to compare the times to AKI according to treatment group.

RESULTS

Two hundred twenty-eight matched patients were included. AKI developed in 9 (7.9%) of 114 and 33 (28.9%) of 114 patients in the cefepime and TZP groups, respectively (P < .001). Type of combination therapy remained a significant predictor for AKI in multivariate conditional Poisson analysis in which adjustments were made for age, sex, use of concomitant nephrotoxins, and vancomycin dose (relative risk, 2.5 [95% confidence interval, 1.1-5.8]; P = .03). AKI developed almost 3 times sooner in the TZP group than in the cefepime group (hazard ratio, 2.9 [95% confidence interval, 1.3-6.1]; P = .006). Sensitivity analyses in which adjustment was made for antibiotic indication in addition to the aforementioned variables and excluding those with gastrointestinal infection revealed similar results.

CONCLUSION

Among hospitalized children at our institution, combination therapy with vancomycin and TZP was associated with an incidence of AKI higher than that associated with vancomycin and cefepime.

Acute Kidney Injury in Pediatric Treated with Vancomycin and Piperacillin-Tazobactam in Tertiary Care Hospital

Background

Vancomycin and piperacillin-tazobactam (PTZ) are commonly used as empirical therapy for patients with health care associated infections. Vancomycin has been recognized as a nephrotoxic agent and in a few cases in the literature PTZ has been associated with interstitial nephritis nevertheless; the combination of these agents has routinely been used for many years. However, there have been some observational studies that showed high rates of acute kidney injury (AKI) in patients receiving vancomycin and PTZ concomitant treatment compared to patients receiving vancomycin alone. The incidence of AKI in adult patients receiving vancomycin and PTZ concomitant treatment was reported in these studies to be relatively high. Similar studies in pediatric patients are lacking.

Method

We conducted a single center retrospective chart review of 248 pediatric patients receiving one of the following treatments: vancomycin alone 36 patients, vancomycin/PTZ 62 patients, vancomycin/ceftazidime 99 patients, and vancomycin/ceftriaxone 51 patients.

Result

Our results showed a low incidence of AKI in patients on vancomycin/PTZ concomitant treatment where overall incidence was only (4.8%) three cases and only one of them (2.0%) in a patient receiving the vancomycin/ceftriaxone concomitant treatment. No cases of AKI present in patients receiving vancomycin with ceftazidime or vancomycin alone. There were no statistically significant differences between the four treatment groups in terms of AKI incidence, vancomycin trough, and use of nephrotoxins.

Conclusion

Overall, the incidence of AKI was low in our study sample with no statistically significant increased risk when PTZ was used in combination with vancomycin in a pediatric population. However, further investigation with an equal larger sample size is needed to confirm our findings.

Too much of a good thing: a retrospective study of β-lactam concentration-toxicity relationships

Objectives

To determine the existence of concentration-toxicity relationships for common β-lactam antibiotic adverse effects and define thresholds above which toxicity is more likely.

Patients and methods

Retrospective review of consecutive patients treated with piperacillin, meropenem or flucloxacillin who underwent therapeutic drug monitoring (TDM) at St Vincent's Hospital (Sydney, Australia) between January 2013 and December 2015. Adverse events investigated included neurotoxicity, nephrotoxicity, hepatotoxicity and opportunistic Clostridium difficile infection. Toxicity was measured using observational grading criteria, clinical assessment and relevant serum biomarkers. These findings were correlated with trough TDM measurements at the time of toxicity presentation.

Results

TDM results from 378 patients (piperacillin = 223, meropenem = 94 and flucloxacillin = 61) were investigated. There was no difference in baseline patient characteristics across antibiotic groups. A statistically significant elevation in mean serum trough concentrations (Cmin) was found in patients diagnosed with neurotoxicity (piperacillin, P < 0.01; meropenem, P = 0.04; flucloxacillin, P = 0.01) and those who developed nephrotoxicity whilst being treated with piperacillin (P < 0.01) or meropenem (P < 0.01). Incidence of hepatotoxicity and C. difficile was not related to Cmin. Threshold concentrations for which there is 50% risk of developing a neurotoxicity event (piperacillin, Cmin >361.4 mg/L; meropenem, Cmin >64.2 mg/L; flucloxacillin, Cmin >125.1 mg/L) or nephrotoxicity (piperacillin, Cmin >452.65 mg/L; meropenem, Cmin >44.45 mg/L) varied across antibiotics.

Conclusions

Our data reveal an association between toxic concentrations for a number of β-lactam agents and neurotoxic/nephrotoxic effects. We have defined threshold concentrations above which these toxicities become more likely. Clinicians should balance concerns for therapeutic efficacy with potential toxicity when considering aggressive therapy.

Pediatric acute kidney injury induced by concomitant vancomycin and piperacillin-tazobactam

BACKGROUND

Vancomycin is very commonly used in combination with piperacillin-tazobactam (PTZ) as the initial empiric treatment for moderate-severe infection, whenever coverage for both methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa is required. The combination of vancomycin and PTZ in adults has recently been reported to significantly increase the risk of acute kidney injury (AKI) relative to vancomycin monotherapy; such reports in pediatrics, however, are sparse.

METHODS

A retrospective chart review was conducted of pediatric patients, aged 0-14 years, who were admitted to the general wards or intensive care unit and developed AKI after receiving vancomycin and PTZ concomitantly for >48 h. AKI is defined as a decrease in estimated glomerular filtration rate ≥50% from baseline. Cases were identified by reviewing the Adverse Drug Reaction program database at King Saud University Medical City in Saudi Arabia from January 2015 to June 2016.

RESULTS

Eight children admitted to the present hospital and who received concomitant vancomycin and PTZ treatment for pneumonia (n = 7) or febrile neutropenia (n = 1) developed drug-induced nephrotoxicity. Drug Interaction Probability Scale (DIPS) score for causation assessment was 9 in all cases (highly probable).

CONCLUSION

Caution in utilizing the combination of vancomycin and PTZ is warranted in pediatric patients. Health-care professionals should be vigilant if this combination is to be initiated, and ensure close monitoring of renal function. Antibiotic therapy de-escalation should be considered as soon as culture results are available.

Increased Risk of Acute Kidney Injury in Critically Ill Children Treated With Vancomycin and Piperacillin/Tazobactam

OBJECTIVES

Compare the rates of acute kidney injury in critically ill children treated with vancomycin and piperacillin-tazobactam versus vancomycin and ceftriaxone.

DESIGN

Retrospective cohort study.

SETTING

A large tertiary care children's hospital in an urban setting.

PATIENTS

Children greater than or equal to 2 months old admitted to the PICU who received greater than or equal to 48 consecutive hours of vancomycin and piperacillin-tazobactam or vancomycin and ceftriaxone.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Acute kidney injury was defined as a minimum 50% increase in serum creatinine, adjusted for total fluid balance, from baseline over a 48-hour period. Bivariate analysis compared treatment groups and acute kidney injury groups. A multivariable logistic regression model was fit for acute kidney injury including covariable analysis. The study included 93 children. There were no differences between treatment groups in terms of age, severity of illness, baseline renal function, vancomycin dosing, or vancomycin trough concentrations. Children who received vancomycin and piperacillin-tazobactam had a higher cumulative frequency of acute kidney injury than those who received vancomycin and ceftriaxone 915/58 [25.9%] vs 3/35 [8.6%]; p = 0.041). After controlling for vancomycin trough concentration, age, concurrent nephrotoxin exposure, and use of vasopressors, exposure to piperacillin-tazobactam significantly increased the risk of acute kidney injury (adjusted odds ratio, 4.55; 95% CI [1.11-18.7]; p = 0.035) compared with ceftriaxone. Use of vasopressors (adjusted odds ratio, 3.73 [95% CI, 1.14-12.3]) and a vancomycin trough greater than or equal to 15 mg/dL (adjusted odds ratio, 4.12 [95% CI, 1.12-15.2)] was also associated with acute kidney injury. Length of stay was longer in children with acute kidney injury (median, 18.0 days; interquartile range, 7.76-29.7) compared with those without acute kidney injury (median, 6.21 days; interquartile range, 2.92-15.6; p = 0.017).

CONCLUSIONS

In critically ill children, acute kidney injury occurred more in patients treated with vancomycin and piperacillin-tazobactam versus vancomycin plus ceftriaxone. After controlling for covariates, exposure to piperacillin-tazobactam was associated with an increased odds of acute kidney injury development.

Prospective Comparison of Acute Kidney Injury During Treatment With the Combination of Piperacillin-Tazobactam and Vancomycin Versus the Combination of Cefepime or Meropenem and Vancomycin

PURPOSE

To prospectively evaluate the observed incidence of acute kidney injury (AKI) in adult patients receiving the combination of piperacillin-tazobactam and vancomycin versus the combination of cefepime or meropenem and vancomycin for greater than 72 hours.

METHODS

This was a prospective, open-label cohort study at a community academic medical center involving adult patients over a 3-month time period who received either the combination of piperacillin-tazobactam and vancomycin or the combination of cefepime or meropenem and vancomycin for greater than 72 hours. The patients were evaluated for AKI, defined using specific criteria introduced by Kidney Disease: Improving global outcomes (KDIGO) acute kidney injury work group in 2012.

RESULTS

A total of 85 patients receiving either antimicrobial combination were evaluated for AKI. The incidence of AKI was significantly higher in the piperacillin-tazobactam and vancomycin group (37.3%) compared with the cefepime or meropenem and vancomycin group (7.7%; χ² = 7.80, P = .005).

CONCLUSION

The result of this study suggests that the risk of developing AKI is increased in patients receiving the combination of piperacillin-tazobactam and vancomycin versus those receiving the combination of cefepime or meropenem and vancomycin.

Does Combination Therapy With Vancomycin and Piperacillin-Tazobactam Increase the Risk of Nephrotoxicity Versus Vancomycin Alone in Pediatric Patients?

OBJECTIVES: To determine if the incidence of nephrotoxicity is higher in pediatric patients treated with the combination of vancomycin and piperacillin-tazobactam, compared to patients treated with vancomycin alone. Secondary objectives were to determine if admission to an intensive care unit (ICU), higher serum vancomycin trough concentrations (>15 mg/L), or receipt of other nephrotoxic agents were related to the development of nephrotoxicity. METHODS: This was a retrospective, single-center, cohort study of 79 patients treated with vancomycin and 106 patients treated with vancomycin and pipracillin/tazobacatam (TZP). Serum creatinine was trended to determine if patients had nephrotoxicity, which was defined as at least a 100% increase in serum creatinine or an increase of ≥0.5 mg/dL from the baseline value. Fisher's exact test was used to compare the incidence of nephrotoxicity in the vancomycin group to the combination group. Secondary objectives were evaluated by using relative risk (RR). RESULTS: Nephrotoxicity developed in 3 of 79 patients (3.8%) in the vancomycin group and in 25 of 106 patients (23.6%) on combination therapy (p = 0.0001). In patients receiving only vancomycin, there was no statistically significant increase in nephrotoxicity for patients in the ICU (RR 1.85, 95% confidence interval [CI] 0.175-19.62, p = 0.61), those with higher vancomycin troughs (RR 2.32, CI 0.226-23.86, p = 0.48), or those receiving other nephrotoxic medications (RR 2.94, CI 0.2779-31.05, p = 0.37). In the combination group, having higher serum vancomycin trough concentrations increased the risk of nephrotoxicity (RR 5.22, CI 2.407-11.306, p < 0.0001). CONCLUSIONS: Combination therapy with vancomycin and TZP is potentially more nephrotoxic than vancomycin alone. ICU admissions, high vancomycin troughs (>15 mg/L), and concomitant nephrotoxic medications cannot be excluded as risk factors for the observed increase in nephrotoxicity in patients receiving vancomycin and TZP.

Acute Kidney Injury in a Child Receiving Vancomycin and Piperacillin/Tazobactam

Recent reports have described increased risk of acute kidney injury (AKI) in adults receiving concomitant vancomycin and piperacillin/tazobactam, but few reports exist in children. We describe an 8-year-old girl who was admitted to the pediatric intensive care unit with respiratory distress secondary to pneumonia. She began treatment with vancomycin and piperacillin/tazobactam. She developed AKI, and piperacillin/tazobactam and vancomycin were discontinued. Following a furosemide infusion, her AKI resolved and serum creatinine returned to baseline. She later resumed piperacillin/tazobactam monotherapy for multidrug-resistant tracheitis with no evidence of AKI and was eventually discharged to a long-term care facility. The Naranjo probability scale supports a probable drug-related adverse event. Clinicians must be aware of the possibility of AKI with this combination and should monitor renal function and vancomycin concentrations vigilantly. Future prospective studies are needed to explore the incidence and clinical characteristics associated with AKI after this combination in children.

Comparative Incidence of Acute Kidney Injury in Critically Ill Patients Receiving Vancomycin with Concomitant Piperacillin-Tazobactam or Cefepime: A Retrospective Cohort Study

STUDY OBJECTIVE

The combination of vancomycin and piperacillin-tazobactam has been associated with an increased risk of acute kidney injury (AKI) in non-critically ill patient populations, but it is still unknown if this association exists in critically ill patients. The objective of this study was to compare the incidence of AKI development during therapy or within 72 hours after completion of therapy in adult critically ill patients who received vancomycin with concomitant piperacillin-tazobactam or cefepime.

DESIGN

Retrospective cohort study.

SETTING

Medical, surgical, and neuroscience intensive care units (ICUs) within a single tertiary care hospital.

PATIENTS

A total of 122 critically ill patients who received at least 48 hours of combination therapy with vancomycin and piperacillin-tazobactam (49 patients) or vancomycin and cefepime (73 patients) during an ICU admission between September 2012 and December 2014.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was AKI development, as determined by the Acute Kidney Injury Network criteria, during combination therapy or within 72 hours of completion of combination therapy. The inverse probability of the treatment-weighting (IPTW) approach was used to account for potential treatment selection bias. AKI incidence was assessed in the unadjusted and propensity score-weighted cohorts. Of the 122 patients, 37 patients (30.3%) developed AKI. In the unadjusted analysis, the incidence of AKI was similar in the piperacillin-tazobactam group compared with the cefepime group (32.7% vs 28.8%, p=0.647). The average treatment effect between the groups was not significant, showing no association between β-lactam choice and AKI (β = -0.004, p=0.958). Secondary outcomes were ICU length of stay, hospital length of stay, AKI duration, and need for renal replacement therapy. The choice of β-lactam was not a significant predictor of any of these outcomes: ICU length of stay (β = 0.436, p=0.780), hospital length of stay (β = 3.819, p=0.125), AKI duration (β = -4.027, p=0.283), and need for renal replacement therapy (β = 2.828, p=0.161).

CONCLUSION

After adjusting for propensity to receive each of the treatment choices, no significant difference was found in the incidence of AKI development or other outcomes between the groups. The previously described finding that concomitant vancomycin and piperacillin-tazobactam increases AKI in non-critically ill patients may not be generalizable to the critically ill population. Prospective evaluation of this hypothesis is warranted.

Top Guns: The "Maverick" and "Goose" of Empiric Therapy

BACKGROUND

Vancomycin and piperacillin-tazobactam are commonly used first guns in the empiric management of critically ill patients. Current studies suggest an increased prevalence of acute kidney injury with concomitant use, however, these studies are few and limited by small sample size. The purpose of this study was to compare the prevalence of nephrotoxicity after treatment with vancomycin alone and concomitant vancomycin and piperacillin-tazobactam treatment at our institution.

HYPOTHESIS

Concomitant vancomycin and piperacillin-tazobactam-treated patients will experience greater prevalence of nephrotoxicity compared with vancomycin-only treated patients.

METHODS

This was a retrospective cohort of patients treated with vancomycin for gram-positive or mixed infections in our facility from 2005 to 2009 who were not receiving hemodialysis at the time of admission. Included patients were stratified by treatment with vancomycin, vancomycin/piperacillin-tazobactam, or vancomycin/an alternative gram-negative rod (GNR) antibiotic. p values for categorical variables were computed using χ(2) while continuous variables were computed using Kruskal-Wallis. Variables deemed statistically significant (< 0.05) were included in the multivariable, log-binomial regression model. Relative risk (RR) and 95% confidence intervals (CI), and p values were computed using a generalized estimating equation (GEE) approach with robust standard errors (i.e., Huber White "sandwich variance" estimates) to accommodate a correlated data structure corresponding to multiple episodes of infection per individual.

RESULTS

A total of 530 patients with 1,007 episodes of infection, were treated with vancomycin (150 patients/302 episodes of infection), vancomycin/piperacillin-tazobactam (213 patients/372 episodes of infection), or vancomycin/GNR alternative (167 patients/333 episodes of infection). Patient demographics, comorbidities, sites of infection, and organisms of infection were compared among groups. After adjusting for statistically significant variables, neither vancomycin/piperacillin-tazobactam (RR = 1.1, 95% CI = 0.99-1.2; p = 0.073) nor vancomycin/GNR alternative (RR = 1.1, 95% CI = 0.98-1.2; p = 0.097) were found to be associated with an increased risk for nephrotoxicity compared with vancomycin alone.

CONCLUSION

A difference in nephrotoxicity was not observed between vancomycin and vancomycin/piperacillin-tazobactam-treated patients at our institution. Concomitant use as empiric therapy is appropriate, although larger sample sizes are needed to analyze closely this relation among at-risk subsets of this population.

Fever and Reversible Laboratory Abnormalities Associated with Prolonged Use of Piperacillin-Tazobactam in Children

Piperacillin-tazobactam is used frequently in pediatric patients with complicated appendicitis and other intra-abdominal infections. We report 10 pediatric patients who developed a piperacillin-tazobactam-associated adverse reaction characterized by fever, rash, hematologic abnormalities and transaminitis. Physicians should be aware of this entity in patients treated with a prolonged course of piperacillin-tazobactam. Prompt identification can obviate unnecessary diagnostic testing and treatment.

Oral penicillin-associated acute kidney injury in an infant with acute pyelonephritis

Beta-lactam-associated acute tubulointerstitial nephritis (ATIN) is a rare condition in childhood. We report the case of an infant with penicillin-associated ATIN and concomitant acute pyelonephritis resulting in the development of severe acute kidney injury (AKI). The treatment consisted of penicillin suspension and appropriate AKI management, which required a short period of dialysis. Finally, full recovery and normalization of laboratory parameters occurred. We present here the first case of oral penicillin-associated ATIN in childhood.

Evaluation of febrile, nonneutropenic pediatric oncology patients with central venous catheters who are not given empiric antibiotics

OBJECTIVE

To evaluate the practice of empiric antibiotics for febrile, nonneutropenic pediatric oncology patients with a central venous catheter (CVC) in place.

STUDY DESIGN

Episodes of fever without neutropenia (absolute neutrophil count [ANC] ≥500 cells/mm(3)) were reviewed retrospectively in pediatric oncology patients with a CVC undergoing chemotherapy. Characteristics and symptoms were compared between patients with bacteremia and patients without bacteremia.

RESULTS

A total of 392 episodes of nonneutropenic fever in 138 subjects (52 females; 38%) were reviewed. In this cohort, the median age at an episode was 7 years, and the majority of patients had a diagnosis of acute leukemia (54%). Median ANC was 3100 cells/mm(3) (IQR, 1570-5980 cells/mm(3)). Median temperature was 38.7°C (IQR, 38.3-39.2°C). Twenty-four infectious episodes (6%) occurred in 18 subjects, and 5 CVCs required removal; all patients requiring removal admitted and received antibiotics owing to chills. There were no significant difference in age, sex, or ANC between patients with bacteremia and those without bacteremia; however, mean temperature was higher in the patients with bacteremia (39.4°C vs 38.7°C; P = .003). No deaths due to sepsis occurred, and no CVCs were removed because antibiotics were not administered empirically.

CONCLUSION

Our practice of observing pediatric oncology patients undergoing chemotherapy with CVCs who are not neutropenic does not appear to lead to increased serious adverse outcomes and avoids antibiotic exposure for >90% of patients without a bacterial infection.

Nephrotoxicity Risk Factors and Intravenous Vancomycin Dosing in the Immediate Postoperative Period Following Antibiotic-Impregnated Cement Spacer Placement

BACKGROUND

Several case reports have documented acute kidney injury (AKI) attributable to antibiotic-impregnated cement (AIC) spacers.

OBJECTIVES

To identify AKI risk factors among patients who underwent AIC placement and determine whether vancomycin-AIC placement affects systemic vancomycin dosing.

METHODS

Phase 1 was a case-control study to identify AKI risk factors among patients who underwent AIC placement. Cases experienced AKI; controls had unchanged renal function. Phase 2 was a retrospective cohort study. Patients who received ≥72 hours of intravenous (IV) vancomycin were divided into 2 groups according to whether they underwent vancomycin-AIC placement. Primary outcome was number of vancomycin dosing changes.

RESULTS

Phase 1: Among 26 cases and 74 controls AKI risk factors on univariate and multivariable analysis included exposure to angiotensin-converting-enzyme (ACE) inhibitor exposure within 7 days of AIC placement (42% vs 20%, P = 0.03) and piperacillin-tazobactam within 7 days following AIC placement (31% vs 12%, P = 0.03). Phase 2: Among 53 patients who underwent vancomycin-AIC placement and 104 who underwent another surgery type, vancomycin was adjusted more frequently in patients who underwent vancomycin-AIC placement (28% vs 15%, P = 0.06).

CONCLUSIONS

Among patients who undergo AIC placement with vancomycin and/or tobramycin, exposure to ACE inhibitors and piperacillin-tazobactam are associated with increased risk of AKI in the immediate postoperative period. No empirical adjustments to IV vancomycin dosing are necessary in patients undergoing vancomycin-AIC placement.