Protective Effects of Different Antioxidants and Amrinone on Vancomycin-Induced Nephrotoxicity

Reno-protective effect of fenofibrate and febuxostat against vancomycin-induced acute renal injury in rats: Targeting PPARγ/NF-κB/COX-II and AMPK/Nrf2/HO-1 signaling pathways

BACKGROUND

Vancomycin (VCM) is used clinically to treat serious infections caused by multi-resistant Gram-positive bacteria, although its use is severely constrained by nephrotoxicity. This study investigated the possible nephroprotective effect of febuxostat (FX) and/or fenofibrate (FENO) and their possible underlying mechanisms against VCM-induced nephrotoxicity in a rat model.

METHODS

Male Wistar rats were randomly allocated into five groups; Control, VCM, FX, FENO, and combination groups. Nephrotoxicity was evaluated histopathologically and biochemically. The oxidative stress biomarkers (SOD, MDA, GSH, total nitrite, GPx, MPO), the apoptotic marker, renal Bcl-2 associated X protein (Bax), and inflammatory and kidney injury markers (IL-1β, IL-6, TNF-α, Nrf2, OH-1, kappa-light-chain-enhancer of activated B cells (NF-κB), NADPH oxidase, Kim-1, COX-II, NGAL, Cys-C were also evaluated.

RESULTS

VCM resulted in significant elevation in markers of kidney damage, oxidative stress, apoptosis, and inflammatory markers. Co-administration of VCM with either/or FX and FENO significantly mitigated nephrotoxicity and associated oxidative stress, inflammatory and apoptotic markers. In comparison to either treatment alone, a more notable improvement was observed with the FX and FENO combination regimen.

CONCLUSION

Our findings show that FX, FENO, and their combination regimen have a nephroprotective impact on VCM-induced kidney injury by suppressing oxidative stress, apoptosis, and the inflammatory response. Renal recovery from VCM-induced injury was accomplished by activation of Nrf2/HO-1 signaling and inhibition of NF-κB expression. This study highlights the importance of FX and FENO as effective therapies for reducing nephrotoxicity in VCM-treated patients.

A comprehensive review of the botany, ethnopharmacology, phytochemistry, and pharmacological activities of two Iranian Rydingia species (Lamiaceae)

Rydingia michauxii and R. persica, respectively, known as Kase Gol and Goldar in Persian, belong to the family Lamiaceae and they are well known herbal medicine in Iran for the treatment of various diseases, particularly diabetes. This review aims to appraise the phytochemistry, ethnopharmacology, and pharmacological activities of Rydingia species growing in Iran and assess their potential in clinical applications. Besides, it critically evaluates existing literature and looks into the perspective for further research and utilization. All available scientific literature was consulted using the database searches involving Google Scholar, PubMed, and Web of Science applying the keyword Rydingia and its Syn; Otostegia. Only the search results that are associated with the Iranian species R. michauxii and R. persica are included in this review. α-pinene, carvacrol, caryophyllene oxide, diisooctyl phthalate, dillapiole, eugenol, hexadecanoic acid, and pentacosane are the major constituents of the essential oils of the Rydingia species. Additionally, these species produce bioactive flavonoids, phenolic acids, steroids, and terpenoids. Extracts and active compounds from Rydingia species have been reported to possess various pharmacological activities including antidiabetic, anti-inflammatory, antimalarial, antimicrobial, antioxidant, cytotoxic, and lipid-lowering properties. Based on the information available to date on the Iranian Rydingia species, it will be worth subjecting these species to further developmental work involving preclinical and clinical trials.

Leonurine alleviates vancomycin nephrotoxicity via activating PPARγ and inhibiting the TLR4/NF-κB/TNF-α pathway

Vancomycin (VCM) is the first-line antibiotic for severe infections, but nephrotoxicity limits its use. Leonurine (Leo) has shown protective effects against kidney damage. However, the effect and mechanism of Leo on VCM nephrotoxicity remain unclear. In this study, mice and HK-2 cells exposed to VCM were treated with Leo. Biochemical and pathological analysis and fluorescence probe methods were performed to examine the role of Leo in VCM nephrotoxicity. Immunohistochemistry, q-PCR, western blot, FACS, and Autodock software were used to verify the mechanism. The present results indicate that Leo significantly alleviates VCM-induced renal injury, morphological damage, and oxidative stress. Increased intracellular and mitochondrial ROS in HK-2 cells and decreased mitochondrial numbers in mouse renal tubular epithelial cells were reversed in Leo-administrated groups. In addition, molecular docking analysis using Autodock software revealed that Leo binds to the PPARγ protein with high affinity. Mechanistic exploration indicated that Leo inhibited VCM nephrotoxicity via activating PPARγ and inhibiting the TLR4/NF-κB/TNF-α inflammation pathway. Taken together, our results indicate that the PPARγ inhibition and inflammation reactions were implicated in the VCM nephrotoxicity and provide a promising therapeutic strategy for renal injury.

The preventive effect of Gastrodia elata Blume extract on vancomycin-induced acute kidney injury in rats

BACKGROUND

Gastrodia elata Blume (GEB), a traditional medicinal herb, has been reported to have pharmacological effect including protection against liver, neuron and kidney toxicity. However, explanation of its underlying mechanisms remains a great challenge. This study investigated the protective effects of GEB extract on vancomycin (VAN)-induced nephrotoxicity in rats and underlying mechanisms with emphasis on the anti-oxidative stress, anti-inflammation and anti-apoptosis. The male Sprague-Dawley rats were randomly divided three groups: control (CON) group, VAN group and GEB group with duration of 14 days.

RESULTS

The kidney weight and the serum levels of blood urea nitrogen and creatinine in the GEB group were lower than the VAN group. Histological analysis using hematoxylin & eosin and periodic acid Schiff staining revealed pathological changes of the VAN group. Immunohistochemical analysis revealed that the expression levels of N-acetyl-D-glucosaminidase, myeloperoxidase and tumor necrosis factor-alpha in the GEB group were decreased when compared with the VAN group. The number of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive cells, phosphohistone and malondialdehyde levels were lower in the GEB group than VAN group. The levels of total glutathione in the GEB group were higher than the VAN group.

CONCLUSIONS

The findings of this study suggested that GEB extract prevents VAN-induced renal tissue damage through anti-oxidation, anti-inflammation and anti-apoptosis.

Protective effects of vitamin D3 (cholecalciferol) on vancomycin-induced oxidative nephrotoxic damage in rats

CONTEXT

Vancomycin (VCM), an important antibiotic against refractory infections, has been used to treat secondary infections in severe COVID-19 patients. Regrettably, VCM treatment has been associated with nephrotoxicity. Vitamin D₃ can prevent nephrotoxicity through its antioxidant effect.

OBJECTIVE

This study tests the antioxidant effect of vitamin D₃ in the prevention of VCM-induced nephrotoxicity.

MATERIALS AND METHODS

Wistar Albino rats (21) were randomly divided into 3 groups: (A) control; (B) VCM 300 mg/kg daily for 1 week; and (C) VCM plus vitamin D₃ 500 IU/kg daily for 2 weeks. All the rats were sacrificed and serum was separated to determine kidney function parameters. Their kidneys were also dissected for histological examination and for oxidative stress markers.

RESULTS

Lipid peroxidation, creatinine, and urea levels decreased significantly (p < 0.0001) in the vitamin D₃-treated group (14.46, 84.11, 36.17%, respectively) compared to the VCM group that was given VCM (MIC<2 μg/mL) only. A significant increase was observed in superoxide dismutase levels in the vitamin D₃-treated group (p < 0.05) compared to rats without treatment. Furthermore, kidney histopathology of the rats treated with vitamin D₃ showed that dilatation, vacuolization and necrosis tubules decreased significantly (p < 0.05) compared with those in the VCM group. Glomerular injury, hyaline dystrophy, and inflammation improved significantly in the vitamin D₃ group (p < 0.001, p < 0.05, p < 0.05, respectively) compared with the VCM group.

DISCUSSION AND CONCLUSIONS

Vitamin D₃ can prevent VCM nephrotoxicity. Therefore, the appropriate dose of this vitamin must be determined, especially for those infected with COVID-19 and receiving VCM, to manage their secondary infections.

Effects of melatonin against acute kidney injury: A systematic review and meta-analysis

INTRODUCTION

Melatonin is a hormone synthesized by the pineal gland, and has antioxidative effects in reducing acute kidney injury (AKI). In the past three years, an increasing number of studies have evaluated whether melatonin has a protective effect on AKI. The study systematically reviewed and assessed the efficacy and safety of melatonin in preventing AKI.

MATERIAL AND METHODS

A systematic literature search was conducted in the PubMed, Embase, and Web of Science databases on February 15, 2023. Eligible records were screened according to the inclusion and exclusion criteria. The odds ratio and Hedges' gwith the corresponding 95% confidence intervals were selected to evaluate the effects of melatonin on AKI. We pooled extracted data using a fixed- or random-effects model based on a heterogeneity test.

RESULTS

There were five studies (one cohort study and four randomized controlled trials) included in the meta-analysis. Although the glomerular filtration rate (GFR) may be significantly improved by melatonin, the incidence of AKI was not significantly decreased in the melatonin group compared with the control group in randomized controlled trials (RCTs).

CONCLUSIONS

In our study, the present results do not support a direct effect of melatonin use on the reduction of AKI. More well-designed clinical studies with larger sample size are required in the future.

The role of inflammation in cadmium nephrotoxicity: NF-κB comes into view

Kidney diseases are major health problem and understanding the underlined mechanisms that lead to kidney diseases are critical research points with a marked potential impact on health. Cadmium (Cd) is a heavy metal that occurs naturally and can be found in contaminated food. Kidneys are the most susceptible organ to heavy metal intoxication as it is the main route of waste excretion. The harmful effects of Cd were previously well proved. Cd induces inflammatory responses, oxidative injury, mitochondrial dysfunction and disturbs Ca²⁺ homeostasis. The nuclear factor-kappa B (NF-κB) is a cellular transcription factor that regulates inflammation and controls the expression of many inflammatory cytokines. Therefore, great therapeutic benefits can be attained from NF-κB inhibition. In this review we focused on certain compounds including cytochalasin D, mangiferin, N-acetylcysteine, pyrrolidine dithiocarbamate, roflumilast, rosmarinic acid, sildenafil, sinapic acid, telmisartan and wogonin and certain plants as Astragalus Polysaccharide, Ginkgo Biloba and Thymus serrulatus that potently inhibit NF-κB and effectively counteracted Cd-associated renal intoxication. In conclusion, the proposed NF-κB involvement in Cd-renal intoxication clarified the underlined inflammation associated with Cd-nephropathy and the beneficial effects of NF-κB inhibitors that make them the potential to substantially optimize treatment protocols for Cd-renal intoxication.

Vancomycin Pharmacokinetics in a Pregnancy Rat Model

Vancomycin usage is often unavoidable in pregnant patients; however, literature suggests vancomycin can cross the placental barrier and reach the fetus. Understanding the mass transit of vancomycin to the fetus is important in pregnancy. We aimed to (i) identify a relevant population pharmacokinetic (PK) model for vancomycin in pregnancy and (ii) estimate PK parameters and describe the mass transit of vancomycin from mother to pup kidneys. Pregnant Sprague-Dawley rats (i.e., trimester 1 and trimester 3) received 250 mg/kg vancomycin once daily for three days through intravenous injection via an internal jugular vein catheter. Vancomycin concentrations in maternal plasma and pup kidneys were quantified via liquid chromatography-tandem mass spectrometry (LC-MS/MS). Multiple compartment models were fitted and assessed using a nonparametric approach with Pmetrics. A total of 10 vancomycin-treated rats and 48 pups contributed PK data. A 3-compartment model adjusted for trimester fit the data well (maternal plasma Bayesian, observed versus predicted R² = 0.978; pup kidney Bayesian, observed versus predicted R² = 0.999). The mean rate constant for vancomycin mass transit to the pup kidney was 0.72 h^-1 for trimester 1 dams and 0.75 h^-1 for trimester 3 dams. Median vancomycin concentrations in pup kidneys from trimester 3 were significantly higher than those in trimester 1 (8.62 versus 0.36 μg/mL, P < 0.001). Vancomycin transited to the fetus from the mother and was; kidney accumulation differed by trimester. This model may be useful for a translational understanding of vancomycin distribution in pregnancy to ensure efficacious and safe doses to both mother and fetus.

Using Japanese big data to investigate novel factors and their high-risk combinations that affect vancomycin-induced nephrotoxicity

AIMS

Several factors related to vancomycin-induced nephrotoxicity (VIN) have not yet been clarified. In the present study, we used Japanese big data to investigate novel factors and their high-risk combinations that influence VIN.

METHODS

We employed a large Japanese electronic medical record database and included patients who had been administered intravenous vancomycin between June 2000 and December 2020. VIN was defined as an increase in serum creatinine ≥0.5 mg/dL or 1.5-fold higher than the baseline. The outcomes were: (1) factors affecting VIN that were identified using multiple logistic regression analysis, and (2) combinations of factors that affect the risk of VIN according to a decision tree analysis, which is a typical machine learning method.

RESULTS

Of the 7,306 patients that were enrolled, VIN occurred in 14.2% of them (1,035). A multivariate analysis extracted 22 variables as independent factors. Concomitant ramelteon use (odds ratio; 0.701, 95% confidence interval; 0.512-0.959), ward pharmacy service (0.741, 0.638-0.861), duration of VCM <7 days (0.748, 0.623-0.899) and trough concentrations 10-15 mg/L (0.668, 0.556-0.802) reduce the risk of VIN. Meanwhile, concomitant piperacillin-tazobactam use (2.056, 1.754-2.409) and piperacillin use (2.868, 1.298-6.338) increase the risk. The decision tree analysis showed that a combination of vancomycin trough concentrations ≥20 mg/L and concomitant piperacillin-tazobactam use was associated with the highest risk.

CONCLUSIONS

We revealed that the concomitant ramelteon use and ward pharmacy service may decrease the risk of VIN, while the concomitant use of not only piperacillin-tazobactam but also piperacillin may increase the risk.

Renoprotective Effects of Melatonin against Vancomycin-Related Acute Kidney Injury in Hospitalized Patients: a Retrospective Cohort Study

Vancomycin is associated with nephrotoxicity, and the mechanism may in part be related to oxidative stress. In vitro and preclinical studies suggest that melatonin supplementation decreases oxidative stress. The objective of this study was to evaluate concomitant use of melatonin and vancomycin and the incidence of acute kidney injury (AKI). We performed a retrospective cohort study at a large community medical center. All consecutive patients admitted to the medical center between January 2016 and September 2020 who received vancomycin therapy alone or concomitantly with melatonin as part of ordinary care were considered for inclusion. The primary endpoint was the development of AKI, defined as an absolute increase in serum creatinine of ≥0.3 mg/dl or a ≥50% increase in serum creatinine. All data were analyzed using descriptive statistics. A multivariable logistic regression was constructed to account for potential confounding variables. We identified a total of 303 adult patients meeting inclusion and exclusion criteria treated with vancomycin, 101 of which received melatonin concomitantly. Overall baseline characteristics were similar between the two groups except for the incidence of bacteremia/sepsis. After controlling for the vancomycin area under the curve, baseline creatinine clearance, and intensive care unit admission in a multivariable logistic regression analysis, melatonin use was associated with a 63% decrease in AKI (odds ratio [OR], 0.37; 95% confidence interval [CI], 0.14 to 0.96; P = 0.041). Melatonin use was associated with a significant reduction in vancomycin-related AKI. Although this was a retrospective study with a small sample size, given the magnitude of the difference seen, further large prospective studies are warranted.

Pediatric onco-nephrology: time to spread the word : Part I: early kidney involvement in children with malignancy

Onco-nephrology has been a growing field within the adult nephrology scope of practice. Even though pediatric nephrologists have been increasingly involved in the care of children with different forms of malignancy, there has not been an emphasis on developing special expertise in this area. The fast pace of discovery in this field, including the development of new therapy protocols with their own kidney side effects and the introduction of the CD19-targeted chimeric antigen receptor T cell (CAR-T) therapy, has introduced new challenges for general pediatric nephrologists because of the unique effects of these treatments on the kidney. Moreover, with the improved outcomes in children receiving cancer therapy come an increased number of survivors at risk for chronic kidney disease related to both their cancer diagnosis and therapy. Therefore, it is time for pediatric onco-nephrology to take its spot on the expanding subspecialties map in pediatric nephrology.

Protective Effects of Hydroalcoholic Extract of Rosa canina Fruit on Vancomycin-Induced Nephrotoxicity in Rats

Vancomycin-induced nephrotoxicity (VIN) has been reported to occur in 5–35% of recipient patients. The aims of the study were to evaluate protective effects of Rosa canina (RC) on VIN in rats. Rats were randomly divided into five groups as follows: control group I, group II (received VAN 400 mg/kg/day, every 12 h at doses of 200 mg/kg/day, for 7 consecutive days), group III (VAN + RC 250 mg/kg/day, for 7 consecutive days), group IV (VAN + RC 500 mg/kg/day, for consecutive days), and group V (received RC 500 mg/kg/day, for consecutive 7 days). On the eighth day after anesthetizing the animals, blood samples were taken from the heart, and then, the kidneys were removed to investigate kidney function, oxidative stress, and histopathological marker. Also, the chemical composition of RC extract was identified by GC-MS analysis. Oral dose of 500 mg/kg RC extract significantly reduced the serum levels of blood urea nitrogen (BUN), creatinine (Cr), malondialdehyde (MDA), and nitric oxide (NO) and also the kidney tissue MDA, protein carbonyl, and NO metabolites (nitrite) levels compared to the VAN-treated group (P < 0.05). Based on histopathological analysis, RC extract at the dose of 500 mg/kg inhibited the destructive effects of VAN on kidney tissues. GC-MS analysis indicated that the main compositions were found to be lactose (21.96%), 3-t-butyloxaziridine (20.91%), and 5-oxymethylfurfurole (16.75%). The results indicated that oral administration of RC was able to reduce VAN-induced nephrotoxicity in rats, possibly through antioxidant pathways.

Chlorogenic acid prevents vancomycin-induced nephrotoxicity without compromising vancomycin antibacterial properties

Vancomycin (VCM) is an effective chemotherapeutic agent commonly used against gram-positive microorganisms but has serious nephrotoxic side effects that limit its effectiveness. New therapeutics and strategies are urgently needed to combat VCM associated nephrotoxicity. In this study, we determined the protective effect of chlorogenic acid (CA) in a rat model of VCM-induced nephrotoxicity. VCM administration led to markedly elevated blood urea nitrogen and serum creatinine levels that could be prevented with CA co-administration. VCM-mediated oxidative stress was also significantly attenuated by CA as reflected by decreased malondialdehyde and nitric oxide in VCM-treated kidneys. CA administration also prevented the VCM-mediated decrease in the renal antioxidative enzyme activities of glutathione reductase, glutathione peroxidase, and catalase and led to increased levels of reduced glutathione that had been depleted by VCM. Moreover, CA administration clearly inhibited VCM-induced expression of nuclear factor-kappa B, inducible nitric oxide synthase and the downstream pro-inflammatory mediators tumor necrosis factor-α and interleukins 1β and 6. Apoptotic markers were also markedly down-regulated with CA. Overall, CA treatment mitigated VCM-induced oxidative and nitrosative stresses and countered the apoptotic and inflammatory effects of VCM. Notably, CA did not affect the antibacterial activity of VCM in vitro.

Effect of N-acetylcysteine against Vancomycin-Induced Nephrotoxicity: A Randomized Controlled Clinical Trial

BACKGROUND

The proposed mechanism of vancomycin-induced nephrotoxicity (VIN) is indirect production of reactive oxygen species in the kidney tissue. This study aimed to investigate the effectiveness of N-acetylcysteine (NAC), an anti-oxidant agent, in the prevention of VIN.

METHODS

Patients who received vancomycin for any indication were randomly divided to drug (NAC) and control groups. The patients in the drug group received oral NAC 600 mg every 12 hours for 10 days, starting concurrently with vancomycin. Serum creatinine (SCr) levels and blood urea nitrogen (BUN) as well as creatinine clearance (CrCl) and 12-hour urine volume were recorded at baseline, every other day during the study, and 12 hours after the last dose of vancomycin on the 10th day. Furthermore, the cases of acute kidney injury (AKI; ≥ 0.5 mg/dL or at least 50% increase in serum creatinine from baseline) were recorded in the two groups.

RESULTS

Over the study period, 84 and 95 patients completed the study in drug and control groups, respectively. SCr and CrCl were significantly lower and higher, respectively, at all-time points (except for baseline) in the NAC compared to the control group. Furthermore, although not statistically significant, 12 cases of vancomycin-induced AKI were observed in the control group (12.63%), while 4 cases (4.76%) were reported from drug group (P = 0.066; relative risk [RR] = 0.377, 95% CI: 0.126-1.124).

CONCLUSION

NAC has the potential for reduction of VIN. However, more studies are necessary to confirm this effect.

Vancomycin-Induced Kidney Injury: Animal Models of Toxicodynamics, Mechanisms of Injury, Human Translation, and Potential Strategies for Prevention

Vancomycin is a recommended therapy in multiple national guidelines. Despite the common use, there is a poor understanding of the mechanistic drivers and potential modifiers of vancomycin-mediated kidney injury. In this review, historic and contemporary rates of vancomycin-induced kidney injury (VIKI) are described, and toxicodynamic models and mechanisms of toxicity from preclinical studies are reviewed. Aside from known clinical covariates that worsen VIKI, preclinical models have demonstrated that various factors impact VIKI, including dose, route of administration, and thresholds for pharmacokinetic parameters. The degree of acute kidney injury (AKI) is greatest with the intravenous route and higher doses that produce larger maximal concentrations and areas under the concentration curve. Troughs (i.e., minimum concentrations) have less of an impact. Mechanistically, preclinical studies have identified that VIKI is a result of drug accumulation in proximal tubule cells, which triggers cellular oxidative stress and apoptosis. Yet, there are several gaps in the knowledge that may represent viable targets to make vancomycin therapy less toxic. Potential strategies include prolonging infusions and lowering maximal concentrations, administration of antioxidants, administering agents that decrease cellular accumulation, and reformulating vancomycin to alter the renal clearance mechanism. Based on preclinical models and mechanisms of toxicity, we propose potential strategies to lessen VIKI.

Vitamin E in the prevention of vancomycin-induced nephrotoxicity

BACKGROUND AND PURPOSE

The use of vancomycin, as a key therapeutic choice for treatment of hazardous infections, may be associated with nephrotoxicity. The proposed mechanism is the indirect production of reactive oxygen species and oxidative stress. The purpose of this study was to investigate the effect of vitamin E as an antioxidant agent in the prevention of vancomycin-induced nephrotoxicity.

EXPERIMENTAL APPROACH

In a matched-groups interventional study, patients who received vancomycin for any indication were assigned to vitamin E (n = 30) and control (n = 60) groups. The patients in experimental group received 400 units of oral vitamin E per day for 10 days started concurrently with vancomycin, while the patients in control group received vancomycin alone. Serum level of creatinine, blood urea nitrogen (BUN), creatinine clearance (CrCl), and 24-h urine output were determined and recorded before the start of interventions, every other day during therapy, and 12 h after the last dose of vancomycin in 10th day of therapy for all patients. Also, the rate of acute kidney injury (AKI) in the two groups was recorded. Finally, the mean values of the measured parameters were compared between the groups.

FINDINGS / RESULTS

Treatment with vitamin E for 10 days resulted in a significant reduction of BUN (from 17.5 ± 7.8 mg/dL at baseline to 11.4 ± 4.8 mg/dL at the end; P < 0.001) along with slightly non-significant increase of CrCl (from 84.7 ± 18.9 mL/min at baseline to 91.3 ± 19.5 mL/min at the end; P = 0.301) in comparison to the control group. However, CrCl decreased significantly in the control group. Vitamin E had no significant effect on 24-h urine output. Regarding vancomycin-induced AKI, 12 cases were observed in the control group, while no case was reported in experimental group (P = 0.041).

CONCLUSION AND IMPLICATIONS

This study showed the beneficial effect of add-on therapy of vitamin E besides vancomycin in reducing AKI, which could be considered as a new potential prophylactic therapy for vancomycin-induced nephrotoxicity.

In vivo protective effects of Ginkgo biloba L. leaf extract against hydrogen peroxide toxicity: cytogenetic and biochemical evaluation

In this study, the protective effects of Ginkgo biloba leaf extract (GbE) against toxicity induced by hydrogen peroxide (H₂O₂) in Swiss albino mice were investigated. Abnormal metaphase number (AMn), mitotic index (MI), micronucleus (MN), and chromosomal abnormalities (CAs) were analyzed for cytogenetic effects. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), blood urea nitrogen (BUN), creatinine, glutathione (GSH), and malondialdehyde (MDA) levels in liver and kidney organs were investigated as indicators of biochemical toxicity. Six experimental groups were formed as a control and treatment group, each containing six animals. The mice in the control group were given tap water, while the mice in the administration group received two different doses of GbE and H₂O₂ for 45 consecutive days. It was observed that H₂O₂ administration caused a significant decrease in MI compared to the control group and caused a significant decrease in the frequency of AMn, MN, and CAs. Chromatid break was the most common type of CAs induced by H₂O₂, and the other CAs types observed in this study were chromosome break, fragment, dicentric, gap, and ring. It has been determined that GbE treatment decreases the clastogenic effects of H₂O₂ and reduces the MN and CAs frequency and causes a re-increase in mitotic cell numbers. It was determined that H₂O₂ administration caused changes in biochemical parameters and resulted in significant increases in serum AST, ALP, ALT, BUN, and creatinine levels. However, the level of MDA, which is an indicator of oxidative damage, increased, and GSH level decreased in liver and kidney tissues. Oxidative damage caused by H₂O₂ in liver and kidney tissues was improved, and all biochemical parameters tested were found to be ameliorated after GbE treatment. This improvement was dependent on the dose of GbE, and improvement in 150 mg/kg bw GbE was found to be more prominent. As a result, the GbE can be used as an antioxidant nutritional supplement to protect against the toxic effects of environmental agents such as H₂O₂.

Melatonin ameliorates the drug induced nephrotoxicity: Molecular insights

BACKGROUND

Drug-induced nephrotoxicity is a frequent adverse event that can lead to acute or chronic kidney disease and increase the healthcare expenditure. It has high morbidity and mortality incidence in 40-70% of renal injuries and accounts for 66% cases of renal failure in elderly population.

OBJECTIVE

Amelioration of drug-induced nephrotoxicity has been long soughed to improve the effectiveness of therapeutic drugs. This study was conducted to review the melatonin potential to prevent the pathogenesis of nephrotoxicity induced by important nephrotoxic drugs.

METHODS

We analyzed the relevant studies indexed in Pubmed, Medline, Scielo and Web of science to explain the molecular improvements following melatonin co-administration with special attention to oxidative stress, inflammation and apoptosis as key players of drug-induced nephrotoxicity.

RESULTS

A robust consensus among researchers of these studies suggested that melatonin efficiently eradicate the chain reaction of free radical production and induced the endogenous antioxidant enzymes which attenuate the lipid peroxidation of cellular membranes and subcellular oxidative stress in drug-induced nephrotoxicity. This agreement was further supported by the melatonin role in disintegration of inflammatory process through inhibition of principle pro-inflammatory or apoptotic cytokines such as TNF-α and NF-κB. These studies highlighted that alleviation of drug-induced renal toxicity is a function of melatonin potential to down regulate the cellular inflammatory and oxidative injury process and to stimulate the cellular repair or defensive mechanisms.

CONCLUSION

The comprehensive nephroprotection and safer profile suggests the melatonin to be a useful adjunct to improve the safety of nephrotoxic drugs.

Evaluation of Fetal and Maternal Vancomycin-Induced Kidney Injury during Pregnancy in a Rat Model

Previous literature suggests that maternal vancomycin crosses the placental barrier to the fetus. Further, early animal studies indicated that kidney injury was not observed in the progeny. These studies were conducted prior to the availability of sensitive biomarkers for kidney injury. Therefore, a previous finding of no renal damage to the infant may be misleading. Vancomycin was administered intravenously to pregnant rats at a dose of 250 mg/kg of body weight/day (N = 6 per trimester) on three consecutive gestational days (GD) during trimesters 1, 2, and 3 (T1, T2, and T3, respectively) in three independent cohorts. The dams carried to term and delivered vaginally on GD 21. Kidneys were harvested from dams and pups and homogenized. Samples were prepared by protein precipitation and injected in a liquid chromatography tandem mass spectrometer, and vancomycin was quantified. The kidney tissue homogenate from dams and pups were analyzed for kidney injury molecule-1 (KIM-1). As trimesters progressed, the quantity of vancomycin increased linearly in the kidneys of both rat dams and pups (P < 0.0001 for T1 and T3, P < 0.0001 for T2 and T3, and P < 0.0001 for T3 and T3 control for both rat dams and pups). KIM-1 concentrations in pup kidneys were significantly higher when dams were administered vancomycin in trimesters 1 (P = 0.0001) and 2 (P = 0.0024) than in controls in trimester 3. Data demonstrate persistence of vancomycin in maternal and rat pup kidneys in all three trimesters of pregnancy with associated damage to the kidney, as indicated by expression of KIM-1.

Vancomycin-Associated Acute Kidney Injury in a Large Veteran Population

BACKGROUND

To determine the association of vancomycin with acute kidney injury (AKI) in relation to its serum concentration value and to examine the risk of AKI in patients treated with vancomycin when compared with a matched cohort of patients receiving non-glycopeptide antibiotics (linezolid/daptomycin).

METHODS

From a cohort of > 3 million US veterans with baseline estimated glomerular filtration rate ≥60 mL/min/1.73 m2, we identified 33,527 patients who received either intravenous vancomycin (n = 22,057) or non-glycopeptide antibiotics (linezolid/daptomycin, n = 11,470). We examined the association of the serum trough vancomycin level recorded within the first 48 h of administration with subsequent AKI in all patients treated with vancomycin and association of vancomycin vs. non-glycopeptide antibiotics use with the risk of incident AKI.

RESULTS

The overall multivariable adjusted ORs of AKI stages 1, 2, and 3 in patients on vancomycin vs. non-glycopeptides were 1.1 (1.1-1.2), 1.2 (1-1.4), and 1.4 (1.1-1.7), respectively. When examined in strata divided by vancomycin trough level, the odds of AKI were similar or lower in patients receiving vancomycin compared to non-glycopeptide antibiotics as long as serum vancomycin levels were ≤20 mg/L. However, in patients with serum vancomycin levels > 20 mg/L, the ORs of AKI stages 1, 2, and 3 in patients on vancomycin vs. non-glycopeptide antibiotics were 1.5 (1.4-1.7), 1.9 (1.5-2.3), and 2.7 (2-3.5), respectively.

CONCLUSIONS

Vancomycin use is associated with a higher risk of AKI when serum levels exceed > 20 mg/L.

Rutin Attenuates Vancomycin-Induced Nephrotoxicity by Ameliorating Oxidative Stress, Apoptosis, and Inflammation in Rats

Nephrotoxicity is the major limiting factor for the clinical use of vancomycin (VCM) for treatment of serious infections caused by multiresistant Gram-positive bacteria. This study investigated the renal protective activity of rutin in a rat model of VCM-induced kidney injury in male Wistar rats. VCM administered intraperitoneally at 200 mg/kg twice daily for 7 successive days resulted in significant elevation of blood urea nitrogen and creatinine, as well as urinary N-acetyl-β-D-glucosaminidase. Coadministration of VCM with oral rutin at 150 mg/kg significantly reduced these markers of kidney damage. Rutin also significantly attenuated VCM-induced oxidative stress, inflammatory cell infiltration, apoptosis, and decreased interleukin-1β and tumor necrosis factor alpha levels (all P < 0.05 or 0.01) in kidneys. Renal recovery from VCM injury was achieved by rutin through increases in Nrf2 and HO-1 and a decrease in NF-κB expression. Our results demonstrated a protective effect of rutin on VCM-induced kidney injury through suppression of oxidative stress, apoptosis, and downregulation of the inflammatory response. This study highlights a role for oral rutin as an effective intervention to ameliorate nephrotoxicity in patients undergoing VCM therapy.

Protective effect of alpha-lipoic acid in methotrexate-induced ovarian oxidative injury and decreased ovarian reserve in rats

To determine whether the possible oxidative effect of methotrexate (Mtx) on ovary and to evaluate the effectiveness of alpha lipoic acid (ALA), which may be useful in many oxidative stress models. Thirty-two female Wistar-albino rats were randomly divided into four groups; control group, alpha lipoic acid group (ALA 100 mg/kg, 10 days), multiple dose Mtx group (Mtx 1 mg/kg 1, 3, 5, 7 days) and Mtx and ALA group (Mtx 1 mg/kg 1, 3, 5, 7 days and ALA 100 mg/kg, 10 days). Serum total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI), tumor necrosis factor-alpha (TNF-α), tissue malondialdehyde (MDA) and activities of glutathione peroxidase (GSH-Px) and catalase (CAT) and anti-Mullerian hormone (AMH) and total ovarian follicle count were evaluated. Mtx administration caused a significant decrease in TAS, a significant increase in TOS and OSI, a significant increase in MDA levels and a decrease in GSH-Px and CAT activity. Moreover the proinflammatory cytokine (TNF-α) was increased in the Mtx group. And AMH values and total follicle count were significantly decreased in Mtx group. However, ALA treatment reversed biochemical results and AMH levels and total follicle count. Alpha lipoic acid ameliorates methotrexate induced oxidative damage of ovarian in rats.

High-Performance Liquid Chromatography Method for Rich Pharmacokinetic Sampling Schemes in Translational Rat Toxicity Models With Vancomycin

A translational need exists to understand and predict vancomycin‐induced kidney toxicity. We describe: (i) a vancomycin high‐performance liquid chromatography (HPLC) method for rat plasma and kidney tissue homogenate; (ii) a rat pharmacokinetic (PK) study to demonstrate utility; and (iii) a catheter retention study to enable future preclinical studies. Rat plasma and pup kidney tissue homogenate were analyzed via HPLC for vancomycin concentrations ranging from 3–75 and 15.1–75.5 μg/mL, respectively, using a Kinetex Biphenyl column and gradient elution of water with 0.1% formic acid: acetonitrile (70:30 v/v). Sprague‐Dawley rats (n = 10) receiving 150 mg/kg of vancomycin intraperitoneally had plasma sampled for PK. Finally, a catheter retention study was performed on polyurethane catheters to assess adsorption. Precision was <6.1% for all intra‐assay and interassay HPLC measurements, with >96.3% analyte recovery. A two‐compartment model fit the data well, facilitating PK exposure estimates. Finally, vancomycin was heterogeneously retained by polyurethane catheters.

The Nephrotoxicity of Vancomycin

Vancomycin use is often associated with nephrotoxicity. It remains uncertain, however, to what extent vancomycin is directly responsible, as numerous potential risk factors for acute kidney injury frequently coexist. Herein, we critically examine available data in adult patients pertinent to this question. We review the pharmacokinetics/pharmacodynamics of vancomycin metabolism. Efficacy and safety data are discussed. The pathophysiology of vancomycin nephrotoxicity is considered. Risk factors for nephrotoxicity are enumerated, including the potential synergistic nephrotoxicity of vancomycin and piperacillin‐tazobactam. Suggestions for clinical practice and future research are given.

Vancomycin-Associated Cast Nephropathy

Vancomycin is a widely prescribed antibiotic, but the exact nature of vancomycin-associated nephrotoxicity is unclear, in particular when considering the frequent coadministration of aminoglycosides. We describe here the initial case of a 56-year-old woman with normal renal function developing unexplained ARF without hypovolemia after administration of vancomycin without coadministration of aminoglycosides. Studying the patient's renal biopsy specimen, we ascertained that obstructive tubular casts composed of noncrystal nanospheric vancomycin aggregates entangled with uromodulin explained the vancomycin-associated ARF. We developed in parallel a new immunohistologic staining technique to detect vancomycin in renal tissue and confirmed retrospectively that deleterious vancomycin-associated casts existed in eight additional patients with acute tubular necrosis in the absence of hypovolemia. Concomitant high vancomycin trough plasma levels had been observed in each patient. We also reproduced experimentally the toxic and obstructive nature of vancomycin-associated cast nephropathy in mice, which we detected using different in vivo imaging techniques. In conclusion, the interaction of uromodulin with nanospheric vancomycin aggregates represents a new mode of tubular cast formation, revealing the hitherto unsuspected mechanism of vancomycin-associated renal injury.

Acute kidney injury induced by antimicrobial agents in the elderly: awareness and mitigation strategies

The use of antimicrobial agents has increased in recent years as treatments have diversified and resistant bacteria have appeared. With increased use of antimicrobial agents, elderly patients are prone to adverse drug reactions (ADRs) as a result of factors such as drug-drug interactions, polypharmacy, long-term use, and over- or under-dosage. In particular, elderly patients using antimicrobials are at increased risk to develop drug-induced acute kidney injury (AKI), which is the most common severe ADR in such patients. AKI is a serious problem that is associated with mortality amongst hospitalized patients. Antimicrobial-induced AKI can be classified into three different types: acute tubular necrosis (ATN), acute interstitial nephritis (AIN), and renal tubule lumen obstruction. AKI can generally be prevented by proper maintenance of fluid balance. To design dosage regimens that ensure efficient drug excretion via the kidney, it is necessary to accurately estimate renal function; however, the kidney undergoes age-dependent structural and functional alterations over time. Therefore, proper management of antimicrobial agents by an antimicrobial stewardship team may lead to decreased incidence of AKI. This article reviews antimicrobial-induced AKI and discusses potential strategies for increasing awareness of AKI and mitigating its clinical effects.

Protective Effects of Cilastatin against Vancomycin-Induced Nephrotoxicity

Vancomycin is a very effective antibiotic for treatment of severe infections. However, its use in clinical practice is limited by nephrotoxicity. Cilastatin is a dehydropeptidase I inhibitor that acts on the brush border membrane of the proximal tubule to prevent accumulation of imipenem and toxicity. The aim of this study was to investigate the potential protective effect of cilastatin on vancomycin-induced apoptosis and toxicity in cultured renal proximal tubular epithelial cells (RPTECs). Porcine RPTECs were cultured in the presence of vancomycin with and without cilastatin. Vancomycin induced dose-dependent apoptosis in cultured RPTECs, with DNA fragmentation, cell detachment, and a significant decrease in mitochondrial activity. Cilastatin prevented apoptotic events and diminished the antiproliferative effect and severe morphological changes induced by vancomycin. Cilastatin also improved the long-term recovery and survival of RPTECs exposed to vancomycin and partially attenuated vancomycin uptake by RPTECs. On the other hand, cilastatin had no effects on vancomycin-induced necrosis or the bactericidal effect of the antibiotic. This study indicates that cilastatin protects against vancomycin-induced proximal tubule apoptosis and increases cell viability, without compromising the antimicrobial effect of vancomycin. The beneficial effect could be attributed, at least in part, to decreased accumulation of vancomycin in RPTECs.

The ameliorative effects of virgin olive oil and olive leaf extract on amikacin-induced nephrotoxicity in the rat

Amikacin is an important antibiotic, and its use is limited because of the induced nephrotoxicity. Thus, search for natural and synthetic agents that can moderate amikacin toxicity never stopped. The present study aims to investigate the possible ameliorative effects of virgin olive oil and olive leaf extract against the amikacin-induced nephrotoxicity in rat.

Methods

48 rats were distributed into 6 groups: 1-Animals of control (C) group were injected intraperitoneally (ip) with saline, 2-(AK); injected ip with amikacin {300 mg/kg/day for 12days}, 3-(OO) group: given olive oil {7 ml/kg/day for 16days}, 4-(OOAK) group: given olive oil as in OO and amikacin for 12days, 5-(OL) group: given olive leaf extract {50 mg/kg/day for 16days}, 6-(OLAK) group: given leaf extract as in OL and amikacin for 12days. Animals were fasted and sacrificed. Serum was used for biochemical analysis and kidneys for histopathology.

Results

Serum urea and creatinine were significantly (P < 0.001) elevated in AK, and significantly dropped in the OOAK and OLAK groups. Serum uric acid was reduced in AK by 45.29%. Kidneys from AK showed necrosis, whereas, those from OOAK and OLAK showed mild histology. The serum triglyceride was decreased by 17.8% in OL, by 37.02% in OOAK and by 31.48% in OLAK. The calculated amikacin effect showed a significant positive correlation with urea (r = 0.521, P = 0.0004), and a negative correlation with uric acid (r = ⿿ 0.58, P < 0.0001).

Conclusion

The study confirmed nephrotoxicity of amikacin in rat which was ameliorated by virgin olive oil and by olive leaf extract. Amikacin did not cause dyslipidemia but reduced serum uric acid.

Effects of pentoxifylline and alpha lipoic acid on methotrexate-induced damage in liver and kidney of rats

The aim of the current study was to investigate the probable protective effects of Pentoxifylline (PTX) and Alpha Lipoic Acid (ALA), which display anti-oxidative efficacy against hepatotoxicity and nephrotoxicity, those being the major side effects of Methotrexate (MTX). Rats were divided into four groups: a control group; MTX (20mg/kg/day) group; MTX+PTX (20mg/kg/day+50mg/kg/day) group; and an MTX+ALA (20mg/kg/day+100mg/kg/day) group. At the end of the experiment, biochemical, histochemical and immunohistochemical analyses were performed on liver and kidney tissues of rats. We determined Glutathione Peroxidase (GSH-Px), Superoxide Dismutase (SOD), Catalase (CAT), Malondialdehyde (MDA), Nitric Oxide (NO) and Xanthine Oxidase (XO) levels in the liver and kidney. Moreover, Gamma Glutamyl Transferase (GGT), Direct Bilirubin (DBil), Blood Urea Nitrogen (BUN), and urea levels were measured in the serum. The histochemical evaluation revealed a significant decrease in MTX caused damage in the PTX- and ALA-treated groups (especially in ALA group). On the other hand, the immune staining of iNOS and TNF-α were observed most densely in the MTX group, while the density decreased in the PTX- and ALA-administered groups. We determined increased GGT, BUN, urea and levels of CAT, MDA, NO, and XO values in both groups, while GSH-Px (an increase in liver tissue) and DBil levels were decreased in the group that received MTX. However, we determined decreased SOD levels in liver tissue. In the PTX and ALA groups, the levels of GGT, BUN and urea as well as the levels of CAT, MDA, NO and XO decreased (SOD increased in the liver tissue), and the levels of GSH-Px and DBil increased. In conclusion, it can be stated that, although ALA is more effective in preventing the toxic effects of MTX on the liver and kidney, PTX also has a preventive effect. As a result, we can readily suggest that ALA and PTX can have protective effects by decreasing MDA, NO, BUN and urea values as antioxidants against MTX-induced damage in liver and kidney of rats.

Vancomycin Nephrotoxicity

Vancomycin earned notoriety for its tendency to cause nephrotoxicity shortly after it was introduced into practice, though the impurities responsible for historically significant rates of nephrotoxicity are of minimal concern today. Increasing usage of vancomycin has provided evidence that the drug itself can be nephrotoxic, but the exact mechanism by which this occurs has not been determined. Various studies have identified risk factors associated with development of vancomycin-associated nephrotoxicity, including total daily dose > 4 grams, trough levels > 20 mg/L, therapy exceeding 6 days, concurrent use of other nephrotoxic agents, preexisting renal disease, obesity, hypotensive episodes, and increasing severity of illness. Preventative strategies beyond risk assessment and therapeutic drug monitoring have shown little promise. Most cases of nephrotoxicity are reversible with discontinuation of vancomycin, but permanent renal damage can occur. This article is intended to serve as a practical review of vancomycin-associated nephrotoxicity, including historical context, risk factors, and common methods to evaluate and define renal dysfunction.

Difference in nephrotoxicity of vancomycin administered once daily and twice daily in rats

We compared the degree of nephrotoxicity of vancomycin (VCM) administered once daily and twice daily in rats. VCM was intraperitoneally administered once daily to rats at a dose of 400 mg/kg (VCM-1-treated) or administered at a dose of 200 mg/kg twice daily at 12-hour intervals (VCM-2-treated) for 7 consecutive days. Creatinine clearance was decreased more markedly in VCM-1 rats relative to VCM-2 rats, although there was no significant difference in renal accumulation of VCM between the two groups. Renal superoxide dismutase activity was lower in VCM-1 rats than that in VCM-2 rats. The magnitude of histological change in kidney tissue was in agreement with the degree of alterations in the abovementioned biochemical values. These results suggest that the nephrotoxic effect of once-daily VCM administration is more pronounced than that of the twice-daily treatment. Our findings provide fundamental evidence for the advantage in choosing a divided VCM administration to attenuate nephrotoxicity.

Adherence to the 2009 consensus guidelines for vancomycin dosing and monitoring practices: a cross-sectional survey of U.S. hospitals

STUDY OBJECTIVES

To describe the implementation of vancomycin dosing and monitoring practices recommended by the consensus guidelines in a diverse sample of hospitals, and to identify needs for quality improvement and research.

DESIGN

Cross-sectional study using an online survey instrument.

SETTING

Making a Difference in Infectious Diseases Pharmacotherapy (MAD-ID) Research Network.

PARTICIPANTS

A total of 163 respondents from MAD-ID who work in antimicrobial stewardship and represent unique hospitals.

MEASUREMENTS AND MAIN RESULTS

The survey population represented a wide range of patient populations (96% adult, 49% pediatric, and 23% long-term care) and settings (52% not-for-profit nonuniversity, 31% university based, and 11% for profit). Automatic consultation of pharmacy services for all vancomycin dosing was reported in 51% of the institutions. Among the dosing and monitoring practices endorsed by the consensus guidelines, participant institutions commonly followed these recommendations: use of trough concentrations without peak concentrations, maintenance of trough concentration higher than 10 mg/L, and target trough concentrations of 15-20 mg/L for complicated infections. In contrast, there was less consistent application of appropriate timing of trough concentrations, use of loading doses, and use of actual body weight. The remaining challenges and controversies surrounding vancomycin dosing are discussed.

CONCLUSION

Despite the availability of consensus guideline recommendations, practices for dosing and monitoring of vancomycin are not universally applied. The findings of this survey highlight many opportunities for future research and quality improvement strategies.

Melatonin attenuates isoflurane-induced acute memory impairments in aged rats

Melatonin is an endogenous hormone with neuroprotective effects. Melatonin levels in elderly patients are reduced after surgeries that require anaesthesia. Whether reduced melatonin levels are important for postoperative cognitive dysfunction (POCD) remains unclear. Here, we investigated the effects of melatonin on cognitive dysfunctions induced by isoflurane and mechanisms underlying these effects. Seventy-two 20-month-old Sprague-Dawley rats were randomly divided into six groups (n = 12). These groups included M1 and M10 groups that received intraperitoneal melatonin at 1 mg/kg or 10 mg/kg, respectively, and an ISO group that received 4 hr of inhaled 2% isoflurane. They also included M1+ISO and M10+ISO groups that received 1 mg/kg or 10 mg/kg of melatonin plus 4 hr of inhaled 2% isoflurane, respectively, and a control group that received an equal volume of saline. Injections were administered daily for 14 consecutive days. Memory was assessed in the Morris water maze. Plasma and hippocampi were harvested to determine melatonin concentrations and MT1/MT2 receptor expression. Rats treated only with isoflurane showed significantly longer latencies in Morris water maze test trials compared with the control group, with shorter time in the probe trial (p < 0.05). Although plasma melatonin levels and MT2 expression in the hippocampus were significantly decreased, MT1 expression was higher in the isoflurane group than in the control group (p < 0.001). However, these parameters did not significantly vary in animals administered melatonin compared with controls. Isoflurane may induce cognitive dysfunction by influencing melatonin and MT1/MT2 levels. Melatonin can improve cognitive dysfunction by normalizing plasma melatonin and its receptor levels.

Risk of vancomycin-induced nephrotoxicity in the population with chronic kidney disease

The antibiotic vancomycin has been available since the 1950s but has been used more commonly since the early 1980s because of the widespread appearance of methicillin-resistant Staphylococcus aureus. Infectious Diseases Society of America guidelines recommend achieving vancomycin trough levels of 10 to 20 μg/mL. Usage of vancomycin in high dosages especially ≥ 4 g/d has led to an increase in the incidence of vancomycin-induced nephrotoxicity, particularly in patients with chronic kidney disease (CKD). This review focuses on the impact of vancomycin-induced nephrotoxicity in patients with CKD. Patients with CKD are at increased risk of developing acute kidney injury and subsequently requiring renal replacement therapy. There is substantial need for vancomycin pharmacokinetic studies to be performed in the population with CKD to develop an optimum vancomycin nomogram in these patients. At present, tight monitoring of vancomycin trough levels in the population with CKD is recommended to help prevent acute kidney injury and its associated high morbidity, mortality and health care costs.

Systematic review and meta-analysis of vancomycin-induced nephrotoxicity associated with dosing schedules that maintain troughs between 15 and 20 milligrams per liter

In an effort to maximize outcomes, recent expert guidelines recommend more-intensive vancomycin dosing schedules to maintain vancomycin troughs between 15 and 20 mg/liter. The widespread use of these more-intensive regimens has been associated with an increase in vancomycin-induced nephrotoxicity reports. The purpose of this systematic literature review is to determine the nephrotoxicity potential of maintaining higher troughs in clinical practice. All studies pertaining to vancomycin-induced nephrotoxicity between 1996 and April 2012 were identified from PubMed, Embase, Cochrane Controlled Trial Registry, and Medline databases and analyzed according to Cochrane guidelines. Of the initial 240 studies identified, 38 were reviewed, and 15 studies met the inclusion criteria. Overall, higher troughs (≥ 15 mg/liter) were associated with increased odds of nephrotoxicity (odds ratio [OR], 2.67; 95% confidence interval [CI], 1.95 to 3.65) relative to lower troughs of <15 mg/liter. The relationship between a trough of ≥ 15 mg/liter and nephrotoxicity persisted when the analysis was restricted to studies that examined only initial trough concentrations (OR, 3.12; 95% CI, 1.81 to 5.37). The relationship between troughs of ≥ 15 mg/liter and nephrotoxicity persisted after adjustment for covariates known to independently increase the risk of a nephrotoxicity event. An incremental increase in nephrotoxicity was also observed with longer durations of vancomycin administration. Vancomycin-induced nephrotoxicity was reversible in the majority of cases, with short-term dialysis required only in 3% of nephrotoxic episodes. The collective literature indicates that an exposure-nephrotoxicity relationship for vancomycin exists. The probability of a nephrotoxic event increased as a function of the trough concentration and duration of therapy.

Nephrotoxicity of vancomycin in patients with methicillin-resistant Staphylococcus aureus bacteraemia

AIM

Vancomycin and teicoplanin are the two most used glycopeptides for the treatment of methicillin-resistant Staphylococcus aureus (MRSA). Vancomycin is suspected to have more nephrotoxicity but this has not been clearly established. The aim of this study was to assess its nephrotoxicity by a consensus definition of acute kidney injury (AKI): the risk (R), injury (I), failure (F), loss and end-stage renal disease (RIFLE) classification.

METHODS

Patients with MRSA bacteraemia who were prescribed either vancomycin or teicoplanin between 2003 and 2008 were classified. Patients who developed AKI were classified by RIFLE criteria. Variables such as comorbidities, laboratory data and medical cost information were also obtained from the database. Outcomes determined were: (i) the rate of nephrotoxicity and mortality; and (ii) the association of nephrotoxicity with the length of hospital stay and costs.

RESULTS

The study included 190 patients (vancomycin 33, teicoplanin 157). Fifteen patients on vancomycin and 27 patients on teicoplanin developed AKI (P = 0.0004). In the vancomycin group, four, eight and three patients were classified to RIFLE criteria R, I and F, respectively. In the teicoplanin group, 17, nine and one patient were classified to RIFLE criteria R, I and F, respectively. Kaplan-Meier analysis showed significant difference in time to nephrotoxicity for the vancomycin group compared to the teicoplanin group. No significant differences were found between the groups in terms of total mortality, length of hospital stay and costs.

CONCLUSION

The study data suggest that vancomycin is associated with a higher likelihood of nephrotoxicity using the RIFLE classification.

Protective effects of thymoquinone on vancomycin-induced nephrotoxicity in rats

AIM

Oxidative stress has been implicated as a potential responsible mechanism in the pathogenesis of vancomycin (VCM)-induced renal toxicity. Therefore, we aimed to investigate the protective effect of thymoquinone (TQ) against VCM-induced nephrotoxicity by tissue oxidant/antioxidant parameters and histological changes in rats.

MATERIALS AND METHODS

Wistar albino rats were randomly separated into four groups consisting of seven rats per group. The groups had normal saline (control group), VCM, VCM and TQ and TQ, respectively. VCM was injected intraperitoneally at a dose of 200 mg/kg and continued at 12-h intervals for 7 days. TQ was injected intraperitoneally at a dose of 10 mg/kg and continued at 24 h intervals for 8 days. Animals were killed and blood samples were analyzed for the levels of serum blood urea nitrogen (BUN) and creatinine (Cr). Kidney specimens were analyzed for levels of malondialdehyde (MDA) and activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) as well as for histopathological changes.

RESULTS

We found that the levels of serum BUN, Cr and kidney tissue MDA were increased in the VCM group. Activities of SOD and GSH-Px in kidney tissue were decreased. TQ administration ameliorated significantly these changes.

CONCLUSION

These results indicate that the TQ produces a protective mechanism against VCM-induced nephrotoxicity and suggest a role of oxidative stress in pathogenesis.

Biopsy-proven vancomycin-associated interstitial nephritis and acute tubular necrosis

Fewer than ten biopsy-proven case reports exist on vancomycin-associated interstitial nephritis (VAIN) and vancomycin-associated acute tubular necrosis (VAATN). Among these, several are confounded by the use of other potentially offending drugs. We report a case of isolated VAIN/VAATN in a patient on no other potentially nephrotoxic agents other than vancomycin. The patient received intravenous vancomycin for coagulase-negative staphylococcus bacteremia. Her baseline serum creatinine of 0.9 mg/dL increased to 9.6 mg/dL after 1 week of therapy during which vancomycin levels peaked at 141 μg/mL. Renal biopsy revealed acute interstitial nephritis with lymphocytic and eosinophilic infiltrate and acute tubular necrosis. Upon discontinuation of vancomycin and administration of prednisone complete renal recovery ensued over a period of 4 weeks.

Melatonin attenuates colistin-induced nephrotoxicity in rats

Colistin-induced nephrotoxicity is a dose-limiting adverse effect when colistin is used against Gram-negative pathogens. This study examined the nephroprotective effect of melatonin against colistin in rats. Rats (n = 7 per group) were treated intravenously twice daily with saline, colistin (at increasing doses from 0.5 to 4.0 mg/kg), melatonin (5 mg/kg), or both melatonin and colistin for 7 days. The severity of renal alteration was examined both biochemically and histologically. The effect of coadministration of melatonin on colistin pharmacokinetics was investigated. Significantly lower urinary N-acetyl-β-d-glucosaminidase excretion was observed from day 1 in the colistin-melatonin group compared to the colistin group (P < 0.0001). Plasma creatinine increased significantly (P = 0.023) only in the colistin group on day 6. Significant histological abnormalities (P < 0.0001) were detected only in the kidneys of the colistin group. Melatonin altered colistin pharmacokinetics; the total body clearance in the colistin-melatonin group (1.82 ± 0.26 ml/min/kg) was lower than in the colistin group (4.28 ± 0.93 ml/min/kg). This is the first study demonstrating the protective effect of melatonin against colistin-induced nephrotoxicity, which indicates that colistin-induced nephrotoxicity is mediated through oxidative stress. It also highlights the potential of coadministering an antioxidant to widen the therapeutic window of this very important last-line antibiotic.