The Nephrotoxicity of Vancomycin

Usefulness of Gram stain examination of peritoneal fluid in postoperative peritonitis to guide empirical antibiotherapy

PURPOSE

In postoperative peritonitis, Gram stain examination (GSE) of peritoneal fluid has been proposed as a guide for the prescription of glycopeptides and antifungal therapy in empirical antibiotherapy. No data support this approach for Gram-positive cocci. We aimed to evaluate the performance of GSE in predicting the results of the culture of peritoneal fluid.

METHODS

In this retrospective single-center study, concordance between GSE and culture of peritoneal fluid was assessed for different types of microorganisms. Factors associated with concordance of the two tests were evaluated in the subpopulation of Gram-positive cocci peritonitis.

RESULTS

Among the 152 episodes, the GSE was negative in 57 cases. The negative predictive value and the positive predictive value were 41% and 87% for Gram-positive cocci (GPC), 31% and 86% for Gram-negative bacilli, and 78% and 94% for fungi. GSE is not a reliable guide for the choice of empirical antibiotherapy and cannot reliably rule out the presence of GPC at culture. If we aim to achieve a high rate of adequacy, the systematic use of glycopeptide in the empirical antibiotherapy may be considered.

CONCLUSION

GSE shows poor performance to predict the results of culture of peritoneal fluid in postoperative peritonitis. Avoiding covering resistant GPC cannot be based on the result of GSE.

Does nephrotoxicity develop less frequently when vancomycin is combined with imipenem-cilastatin than with meropenem? A comparative study

Introduction: Nephrotoxicity is a frequent complication of vancomycin therapy. Experimental studies in different animal species have demonstrated the attenuation of vancomycin-associated nephrotoxicity with cilastatin administration. This study aimed to evaluate if imipenem-cilastatin attenuates vancomycin-associated nephrotoxicity, in patients treated with combinations of vancomycin and carbapenems. Methods: This retrospective, propensity-score matched study was conducted at King Faisal Specialist Hospital and Research Centre, Riyadh and Jeddah. Nephrotoxicity was compared in patients who received imipenem-cilastatin + vancomycin or meropenem + vancomycin. Patients with no history of renal disease who received imipenem-cilastatin + vancomycin or meropenem + vancomycin for a minimum of 72 h, from 1 January 2017 to 31 December 2017, were included. Nephrotoxicity was defined according to the RIFLE criteria (Risk, Injury, Failure, Loss, End-stage renal disease) if sustained for least 72 h. Results: A total of 227 patients were included in the analysis, consisting of 121 patients in the imipenem-cilastatin + vancomycin group, and 106 patients in the meropenem + vancomycin group. In the unmatched data set the rate of nephrotoxicity was 8.2% in imipenem-cilastatin + vancomycin group and 20.7% in the meropenem + vancomycin group (p = .007). Logistic regression analysis showed that imipenem-cilastatin + vancomycin therapy was associated with a 56% lower rate of nephrotoxicity compared to meropenem + vancomycin therapy. Propensity-score matching resulted in rates of nephrotoxicity of 6.2% and 17.1% in the imipenem-cilastatin + vancomycin group and the meropenem + vancomycin groups, respectively (p = .034). Conclusion: Vancomycin-associated nephrotoxicity developed less frequently when vancomycin was combined with imipenem-cilastatin than when combined with meropenem.

Vancomycin Should Be Part of Empiric Therapy for Suspected Bacterial Meningitis

The use of empiric vancomycin plus a third-generation cephalosporin for suspected bacterial meningitis has been recommended since 1997. Although the prevalence of ceftriaxone-nonsusceptible pneumococcal meningitis has decreased, vancomycin should still be included as empiric therapy for bacterial meningitis.

Revising Pediatric Vancomycin Dosing Accounting for Nephrotoxicity in a Pharmacokinetic-Pharmacodynamic Model

This study aimed to suggest an initial pediatric vancomycin dose regimen through population pharmacokinetic-pharmacodynamic modeling. A population pharmacokinetic approach was used to analyze vancomycin concentration-time data from a large pediatric cohort. Pharmacokinetic target attainment for patients with bloodstream isolates was compared with clinical outcome using logistic regression and classification and regression trees. Change in serum creatinine during treatment was used as an indicator of acute nephrotoxicity. Probability of acute kidney injury (50% increase from baseline) or kidney failure (75% increase from baseline) was evaluated using logistic regression. An initial dosing regimen was derived, personalized by age, weight, and serum creatinine, using stochastic simulations. Data from 785 hospitalized pediatric patients (1 day to 21 years of age) with suspected Gram-positive infections were collected. Estimated (relative standard error) typical clearance, volume of distribution 1, intercompartmental clearance, and volume of distribution 2 were (standardized to 70 kg) 4.84 (2.38) liters/h, 39.9 (8.15) liters, 3.85 (17.3) liters/h, and 37.8 (10.2) liters, respectively. While cumulative vancomycin exposure correlated positively with the development of nephrotoxicity (713 patients), no clear relationship between vancomycin area under the plasma concentration-time curve and efficacy was found (102 patients). Predicted probability of acute kidney injury and kidney failure with the optimized dosing regimen at day 5 was 10 to 15% and 5 to 10%, increasing by approximately 50% on day 7 and roughly 100% on day 10 across all age groups. This study presents the first data-driven pediatric dose selection to date accounting for nephrotoxicity, and it indicates that cumulative vancomycin exposure best describes risk of acute kidney injury and acute kidney failure.

Potential renoprotective effects of silymarin against vancomycin-induced nephrotoxicity in rats

Silymarin (SLY), a flavonoid complex isolated from the seeds of Silybum marianum (Asteraceae), has antioxidant, anti-apoptotic, anti-inflammatory, and anti-lipid peroxidative effects. Vancomycin (VA), used for treating serious infections, has been associated with nephrotoxicity, which limits its use. Therefore, this study aimed to investigate the potential renoprotective effects of SLY on VA-induced nephrotoxicity using renal, apoptotic (caspase-3, caspase-8, and caspase-9 enzyme activities), and oxidative stress [nitric oxide (NO) and malondialdehyde (MDA)] markers; serum blood urea nitrogen (BUN) and creatinine levels; and histopathological examination. A total of 49 male Wistar albino rats were used (n = 7): control [saline, intraperitoneally (i.p.)], dimethyl sulfoxide (i.p.), VA [400 mg/(kg-day), i.p.], SLY100 [100 mg/(kg-day), i.p.], VA + SLY50 [50 mg/(kg-day), i.p.], VA + SLY100 [100 mg/(kg-day), i.p.], and VA + SLY200 [200 mg/(kg-day), i.p.]. SLY was administered once daily for 8 days. One day after the first treatment of SLY, VA administration was started and continued for 7 days. The levels of serum creatinine and BUN were evaluated using ELISA, caspase enzyme activities and levels of MDA and NO in the kidney tissues were evaluated by the colorimetric methods. The serum BUN, creatinine, NO, MDA levels, and caspase activities were significantly higher in VA group than in control (p < 0.05). However, caspase activities were significantly lower in VA + SLY200 than in VA (p < 0.05). The MDA, serum BUN, and creatinine levels were significantly lower in VA + SLY (50, 100, and 200) groups than in VA group (p < 0.05). VA + SLY200 was found to be the most effective group based on the caspase activities; MDA, NO, serum BUN, creatinine levels; and histopathological findings.

Clinical Pharmacology of Antibiotics

Antimicrobial pharmacology and its effect on prescribing is quite complex. Selecting an antibiotic that will optimally treat an infection while minimizing adverse effects and the development of resistance is only the first step, as one must also consider the patient's individual pharmacokinetic alterations and the pharmacodynamic properties of the drug when prescribing it as well. Patients with CKD may have alterations in their protein binding, volumes of distribution, kidney clearance, and nonrenal clearance that necessitates antibiotic dose adjustments to prevent the development of toxicity. Knowledge of a drug's pharmacodynamics, defined as the relationship between drug exposure and antibacterial efficacy, provides some guidance regarding the optimal way to make dose adjustments. Different pharmacodynamic goals, such as maximizing the time that free (unbound) drug concentrations spend above the minimum inhibitory concentration (MIC) for time dependent drugs (e.g., β-lactams) or maximizing the free peak-to-MIC ratio for concentration-dependent antibiotics (e.g., aminoglycosides), require different adjustment strategies; for instance, decreasing the dose while maintaining normal dosing frequency or giving normal (or even larger) doses less frequently, respectively. Patients receiving hemodialysis have other important prescribing considerations as well. The nephrologist or patient may prefer to receive antibiotics that can be administered intravenously toward the end of a dialysis session. Additionally, newer dialysis technologies and filters can increase drug removal more than originally reported. This review will discuss the place in therapy, mechanism of action, pharmacokinetic, pharmacodynamic, and other pharmacologic considerations encountered when prescribing commonly used antibiotics in patients with chronic kidney disease or ESKD.

Vancomycin elution from a biphasic ceramic bone substitute

Objectives

The aim of this study was to analyze drain fluid, blood, and urine simultaneously to follow the long-term release of vancomycin from a biphasic ceramic carrier in major hip surgery. Our hypothesis was that there would be high local vancomycin concentrations during the first week with safe low systemic trough levels and a complete antibiotic release during the first month.

Methods

Nine patients (six female, three male; mean age 75.3 years (sd 12.3; 44 to 84)) with trochanteric hip fractures had internal fixations. An injectable ceramic bone substitute, with hydroxyapatite in a calcium sulphate matrix, containing 66 mg of vancomycin per millilitre, was inserted to augment the fixation. The vancomycin elution was followed by simultaneously collecting drain fluid, blood, and urine.

Results

The antibiotic concentration in the drain reached a peak during the first six hours post-surgery (mean 966.1 mg/l), which decreased linearly to a mean value of 88.3 mg/l at 2.5 days. In the urine, the vancomycin concentration reached 99.8 mg/l during the first two days, followed by a logarithmic decrease over the next two weeks to reach 0 mg/l at 20 days. The systemic concentration of vancomycin measured in blood serum was low and decreased linearly from 2.17 mg/l at one hour post-surgery to 0 mg/l at four days postoperatively.

Conclusion

This is the first long-term pharmacokinetic study that reports vancomycin release from a biphasic injectable ceramic bone substitute. The study shows initial high targeted local vancomycin levels, sustained and complete release at three weeks, and systemic concentrations well below toxic levels. The plain ceramic bone substitute has been proven to regenerate bone but should also be useful in preventing bone infection.

Cite this article: M. Stravinskas, M. Nilsson, A. Vitkauskiene, S. Tarasevicius, L. Lidgren. Vancomycin elution from a biphasic ceramic bone substitute. Bone Joint Res 2019;8:49–54. DOI: 10.1302/2046-3758.82.BJR-2018-0174.R2.

Risk factors for vancomycin nephrotoxicity and time course of renal function during vancomycin treatment

PURPOSE

Vancomycin (VCM) is used for the treatment of methicillin-resistant Staphylococcus aureus. Although the risk factors for VCM nephrotoxicity have been evaluated, the time course of renal function during VCM treatment is unknown. We assessed risk factors for VCM nephrotoxicity and how renal function varied over time.

METHODS

We conducted a retrospective analysis of patients receiving intravenous VCM treatment between June 2015 and August 2017 at Tokyo Women's Medical University, Medical Center East. VCM nephrotoxicity was defined as an increase in serum creatinine levels > 50%. We performed multivariate logistic regression analysis to assess risk factors for VCM nephrotoxicity. The time course of renal function with VCM nephrotoxicity was compared and stratified by risk factors for VCM nephrotoxicity. Clinical course of VCM nephrotoxicity and VCM trough concentration were assessed.

RESULTS

In total, 42 (17.3%) of 243 patients developed VCM nephrotoxicity. Risk factors for VCM nephrotoxicity were VCM trough concentration > 20 μg/mL and concomitant use of renal hypoperfusion medications (angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, loop/thiazide diuretics, and non-steroidal anti-inflammatory drugs). Although time course of renal function stratified by renal hypoperfusion medications was comparable, the time course of renal function significantly deteriorated in patients with loop/thiazide diuretics. Focusing on patients continuing VCM treatment, VCM nephrotoxicity recovered in 40% of the patients and VCM trough concentration improved to 10-20 μg/mL in 75% of the patients.

CONCLUSIONS

VCM trough concentration > 20 μg/mL and concomitant use of renal hypoperfusion medications are associated with VCM nephrotoxicity. Recovery of VCM nephrotoxicity was poor compared to the improvement of VCM trough concentration.

Expanding the Role for Kidney Biopsies in Acute Kidney Injury

Acute kidney injury (AKI) is a highly heterogeneous, common, and potentially devastating condition associated with markedly increased hospital length of stay, cost, mortality, and morbidity. Expanding the role for kidney biopsies in AKI may offer fresh insights into disease heterogeneity, molecular mechanisms, and therapeutic targets. A number of challenges face investigators and clinicians considering research biopsies in AKI: ensuring patient safety, ensuring the ethical conduct of research studies, and maximizing the scientific yield of the kidney tissue obtained. The societal benefits of research that lead to novel strategies for preventing and treating AKI would be enormous. Rethinking our current approach to the role of kidney biopsy for AKI diagnosis and research may be a major step toward the promise of personalized medicine in nephrology.

Vancomycin associated acute kidney injury in pediatric patients

INTRODUCTION

Vancomycin associated acute kidney injury (vAKI) is a well known complication in pediatric patients. Identification and characterization of the incidence and risk factors for vAKI in the pediatric population would assist clinicians in potentially preventing or mitigating vAKI.

METHODS AND MATERIALS

A 6 year retrospective cohort study was designed. Patients were included if they were < 19 years of age, received vancomycin as inpatients, and had a baseline SCr and one other SCr drawn during and up to 72 hours after the discontinuation of vancomycin. Data collection included patient demographics, vancomycin doses and length of therapy, vancomycin serum concentrations, and concomitant medications. The Kidney Disease Improving Global Outcomes (KDIGO) criteria were used to characterize acute kidney injury. Descriptive statistical methods were used and ordinal logistic regression was employed to determine variables significantly associated with vAKI.

RESULTS

A total of 7,095 patients met study criteria (55.4% male, median age 4.1 years (IQR 0.67-11.2 years)). Mechanical ventilation was used in 7.9% (n = 563) and mortality was 4.9% (n = 344). A total of 153 concomitant medications were identified. A median of 5 (IQR 3-7) SCr values were obtained and median SCr prior to vancomycin was 0.39 (IQR 0.28-0.57) mg/dL (CrCl 134±58 mL/min/1.73m2). Vancomycin was administered for a median of 2 (IQR 1-3) days (14.9±1.6 mg/kg/dose). vAKI was present in 12.2% (n = 862: KDIGO stage 1 (8.30%, n = 589), KDIGO stage 2 (1.94%, n = 138) KDIGO stage 3 (1.89%, n = 134)). Mean vancomycin serum concentration at 6-8 hours after a dose for patients with vAKI (10.7±8.9 mg/L) was significantly, but not clinically different for patients with no vAKI (7.5±6.3 mg/L). (p<0.05) Ordinal logistic regression identified total dose of vancomycin, vancomycin administration in the intensive care unit, and concomitant medication administration as significant for vAKI. In particular, concomitant administration of several different medications, including nafcillin, clindamycin, and acetazolamide, were noted for strong associations with vAKI. (p<0.05).

CONCLUSIONS

Moderate to severe acute kidney injury due to vancomycin is infrequent in children and associated with concomitant medication use and total dose of vancomycin. Serum vancomycin concentrations are not useful predictors of vAKI in the pediatric population.

Extremely high levels of vancomycin can cause severe renal toxicity

Vancomycin has usually been associated with nephrotoxicity. Generally, this toxicity is presented as proximal tubular cells injury with or without necrosis and as acute interstitial nephritis. However, development of both lesions is uncommonly described in literature. We present a case of vancomycin-induced nephrotoxicity resulting in both acute interstitial nephritis and tubular cells damage confirmed by renal biopsy. Peak and trough levels of 77.11 and 63.60 μg/mL, respectively, were obtained at the first plasma determination. After 8 more plasma determinations and several hemodialysis sessions, vancomycin levels were undetectable 1 month after therapy was stopped. To our knowledge, this is the case report with the highest vancomycin trough levels developing both lesions and describing total vancomycin washout after a biopsy-proven vancomycin toxicity. In conclusion, early vancomycin therapeutic drug monitoring should be performed in order to avoid toxicities where, as seen in our patient, antibiotic exposure could last around 1 month after last dose administration.

Vancomycin-induced acute kidney injury in elderly Chinese patients: a single-centre cross-sectional study

AIMS

The objective of the present study was to investigate the current situation concerning, and risk factors for, vancomycin (VAN)-induced acute kidney injury (VI-AKI) in elderly Chinese patients, to assess outcomes and risk factors in patients who have developed VI-AKI, in order to provide suggestions for improving the prevention and treatment of this condition in these patients.

METHOD

We retrospectively identified elderly older inpatients who had received four or more doses of VAN treatment. We compared patients with VI-AKI with those who received VAN treatment and had not developed AKI (NO-AKI). We defined VI-AKI as developing AKI during VAN therapy or within 3 days after withdrawal of VAN.

RESULTS

A total of 647 out of 862 elderly inpatients were included in the study. Among those excluded, in 89.3% of cases (192/215) this was because of lack of data on serum creatinine (SCr). Among included patients, 32.5% (210/647) of patients received therapeutic drug monitoring (TDM) during VAN therapy. In 66.9% of cases (424/634), there was insufficient TDM, and in 3.9% (25/634) this was appropriate. A total of 102 patients had confirmed VI-AKI, with an incidence of 15.8% (102/647). Multiple logistic regression analysis revealed that hyperuricaemia [odds ratio (OR) = 3.045; P = 0.000)], mechanical ventilation (OR = 1.906; P = 0.022) and concomitant vasopressor therapy (OR = 1.919; P = 0.027) were independent risk factors for VI-AKI; higher serum albumin (OR = 0.885; P = 0.000) was determined to be an independent protective factor for VI-AKI.

CONCLUSIONS

For the elderly Chinese patients treated with VAN, there was insufficient monitoring of SCr, too little use of VAN TDM, and lower rate of patients whose VAN though serum concentrations were not obtained at the correct time. We recommend that hospital managers increase investment in clinical pharmacists, to strengthen professional management. Patients with concomitant hyperuricaemia and on mechanical ventilation and vasopressor therapy should be paid more attention, and a higher serum albumin was determined to be an independent protective factor for VI-AKI.

A Phase 3, Randomized, Double-Blind, Multicenter Study To Evaluate the Safety and Efficacy of Intravenous Iclaprim versus Vancomycin for Treatment of Acute Bacterial Skin and Skin Structure Infections Suspected or Confirmed To Be Due to Gram-Positive Pathogens (REVIVE-2 Study)

Iclaprim is a novel diaminopyrimidine antibiotic that may be an effective and safe treatment for serious skin infections. The safety and effectiveness of iclaprim were assessed in a global phase 3, double-blind, randomized, active-controlled trial. Six hundred thirteen adults with acute bacterial skin and skin structure infections (ABSSSIs) suspected or confirmed to be due to Gram-positive pathogens were randomized to iclaprim (80 mg) or vancomycin (15 mg/kg of body weight), both of which were administered intravenously every 12 h for 5 to 14 days. The primary endpoint was a ≥20% reduction in lesion size compared with that at the baseline at 48 to 72 h after the start of administration of study drug in the intent-to-treat population. Among patients randomized to iclaprim, 78.3% (231 of 295) met this primary endpoint, whereas 76.7% (234 of 305) of those receiving vancomycin met this primary endpoint (difference, 1.58%; 95% confidence interval, -5.10% to 8.26%). This met the prespecified 10% noninferiority margin. Iclaprim was well tolerated, with most adverse events being categorized as mild. In conclusion, iclaprim was noninferior to vancomycin in this phase 3 clinical trial for the treatment of acute bacterial skin and skin structure infections. On the basis of these results, iclaprim may be an efficacious and safe treatment for skin infections suspected or confirmed to be due to Gram-positive pathogens. (This trial has been registered at ClinicalTrials.gov under identifier NCT02607618.).

Drugs and the Kidneys: Clinical Pharmacology Perspectives

The focus of this edition of Clinical Pharmacolgoy & Therapeutics (CPT) is on drugs and renal function and will not include a detailed discussion of kidney disease and its treatment. It is well recognized that drugs affect the kidneys in different ways, while kidney disease impacts drug metabolism and response. It is impossible to underestimate the value of the kidneys to man in health and disease, from regulation of fluid and electrolyte balance to participating in drug metabolism and transport. Additionally, the kidneys serve as targets for drugs used to treat cardiovascular (CV) diseases including hypertension and heart failure, metabolic diseases such as diabetes mellitus and obesity, chronic kidney disease (CKD), as well as playing a role in the regulation of several hormones. Kidney damage may be distinguished from changes in kidney function using biomarkers, as discussed in some detail in this issue.