N-acetylcysteine as a novel prophylactic treatment for ifosfamide-induced nephrotoxicity in children: translational pharmacokinetics

Ifosfamide-induced nephrotoxicity in oncological patients

INTRODUCTION

Ifosfamide is an alkylating chemotherapeutic agent used in the treatment of various neoplasms. Its main adverse effects include renal damage.

AREAS COVERED

A comprehensive review was conducted, including 100 articles from the Scielo, Scopus, and EMBASE databases. Ifosfamide-induced nephrotoxicity is attributed to its toxic metabolites, such as acrolein and chloroacetaldehyde, which cause mitochondrial damage and oxidative stress in renal tubular cells. Literature review found a 29-year average age with no gender predominance and a mortality of 13%. Currently, no fully effective strategy exists for preventing ifosfamide-induced nephrotoxicity; however, hydration, forced diuresis, and other interventions are employed to limit renal damage. Long-term renal function monitoring is essential for patients treated with ifosfamide.

EXPERT OPINION

Ifosfamide remains essential in neoplasm treatment, but nephrotoxicity, often compounded by coadministered drugs, poses diagnostic challenges. Preventive strategies are lacking, necessitating further research. Identifying timely risk factors can mitigate renal damage, and a multidisciplinary approach manages established nephrotoxicity. Emerging therapies may reduce ifosfamide induced nephrotoxicity.

Optimal Delivery of Follow-Up Care Following Treatment for Adults Treated for Ewing Sarcoma

Ewing sarcoma (ES) is a rare, highly malignant sarcoma. It usually presents in the second decade of life; however, patients can be diagnosed as early as newborns and as late as in their seventies. ES is most frequently found in the long bones of the extremities and the pelvis. In older patients, ES can also arise in the soft tissues. Currently, there is no standard schedule for surveillance of adult patients with ES after their initial treatment for localised disease, not only for the early detection of recurrence but also for long-term side effects. Follow-up is based on group recommendations using extrapolated data obtained primarily from studies with paediatric patients. The main objective of this review is to summarise the data available on treatment-associated complications in long-term survivors. Furthermore, we provide a set of recommendations for optimising the follow-up of adults ES survivors, as well as for managing the sequelae that result from intensive multimodal treatment.

Pharmacogenomics in Children

Historically genetics has not been considered when prescribing drugs for children. However, it is clear that genetics are not only an important determinant of disease in children but also of drug response for many important drugs that are core agents used in the therapy of common problems in children. Advances in therapy and in the ethical construct of children's research have made pharmacogenomic assessment for children much easier to pursue. It is likely that pharmacogenomics will become part of the therapeutic decision-making process for children, notably in areas such as childhood cancer where weighing benefits and risks of therapy is crucial.

Drug toxicity in the proximal tubule: new models, methods and mechanisms

The proximal tubule (PT) reabsorbs most of the glomerular filtrate and plays an important role in the uptake, metabolism and excretion of xenobiotics. Some therapeutic drugs are harmful to the PT, and resulting nephrotoxicity is thought to be responsible for approximately 1 in 6 of cases of children hospitalized with acute kidney injury (AKI). Clinically, PT dysfunction leads to urinary wasting of important solutes normally reabsorbed by this nephron segment, leading to systemic complications such as bone demineralization and a clinical scenario known as the renal Fanconi syndrome (RFS). While PT defects can be diagnosed using a combination of blood and urine markers, including urinary excretion of low molecular weight proteins (LMWP), standardized definitions of what constitutes clinically significant toxicity are lacking, and identifying which patients will go on to develop progressive loss of kidney function remains a major challenge. In addition, much of our understanding of cellular mechanisms of drug toxicity is still limited, partly due to the constraints of available cell and animal models. However, advances in new and more sophisticated in vitro models of the PT, along with the application of high-content analytical methods that can provide readouts more relevant to the clinical manifestations of nephrotoxicity, are beginning to extend our knowledge. Such technical progress should help in discovering new biomarkers that can better detect nephrotoxicity earlier and predict its long-term consequences, and herald a new era of more personalized medicine.

[Renal toxicity of anticancer drugs]

The renal toxicity of anticancer drugs is a clinical challenge because of the intrinsic toxicity of some anticancer drugs and because the cancer itself. Indeed, cancer patients are exposed to all types of renal disorders (obstructive, functional, organic because of radiotherapy, paraneoplastic glomerulopathy, thrombotic microangiopathy…). The therapeutic index of anticancer drugs is often narrow and the doses used for optimal efficacy are high. Improving safety requires a better dose adjustment, which depends on the correct evaluation of the renal function. Prevention remains important as the mortality associated with acute renal failure is very high.

Adverse Drug Reactions Across the Age Continuum: Epidemiology, Diagnostic Challenges, Prevention, and Treatments

Adverse drug reactions (ADRs) are common and important complications of drug therapy for children. The risk for ADRs changes over childhood, as do the nature and types of ADRs. Importantly, the risk and nature of ADRs in children are markedly different from those of adults, and adult data cannot be relied on to guide safe drug therapy in children. There are groups of children, notably those with complex and chronic diseases, who are at substantial risk for ADRs. The evaluation of an undesired effect during therapy is ideally accomplished by an organized approach that is a skill that clinicians who care for children-especially those children at high risk for ADRs must have. Additionally, clinicians as well as drug regulatory agencies and industry need to be both vigilant and astute as well as aware that ADRs in children are often different in nature and frequency from those in adults. The increasing use of pharmacogenomics to guide drug dosing and the increasing number of biological agents will provide new sets of challenges to clinicians over the next decade.

Effects of hydrogen sulfide on acetaminophen-induced acute renal toxicity in rats

INTRODUCTION AND AIM

Hydrogen sulfide (H₂S) is an endogenously produced gas-structure mediator. It is proposed to have antioxidant, anti-inflammatory and antiapoptotic effects. Acetaminophen (N-acetyl-P-aminophenol; APAP) is an antipyretic and analgesic medication known as paracetamol. When taken at therapeutic doses there are few side-effects, but at high doses APAP can cause clear liver and kidney damage in humans and experimental animals. In this study, the effects of the H₂S donor of sodium hydrosulfide (NaHS) on acute renal toxicity induced by APAP in rats were researched in comparison with N-acetyl cysteine (NAC).

METHOD

Rats were divided into six groups (n = 7) as control. APAP, APAP + NAC, APAP + NaHS 25 µmol/kg, NaHS 50 µmol/kg and NaHS 100 µmol/kg. After oral dose of 2 g/kg APAP, NAC and NaHS were administered via the i.p. route for 7 days. In renal homogenates, KIM-1 (Kidney Injury Molecule-1), NGAL (neutrophil gelatinase-associated lipocalin), TNF-α and TGFβ levels were measured with the ELISA method for tissue injury and inflammation. In renal tissue, oxidative stress levels were identified by spectrophotometric measurement of TAS and TOS. Histopathologic investigation of renal tissue used caspase 3 staining for apoptotic changes, Masson trichrome and H&E staining for variations occurring in glomerular and tubular systems.

RESULTS

NaHS lowered KIM-1, NGAL, TNF-α, TGF-β and TOS levels elevated in renal tissue linked to APAP and increased TAS values. NaHS prevented apoptosis in the kidney and was identified to ensure histologic amelioration in glomerular and tubular structures. NaHS at 50 µmol/kg dose was more effective, with the effect reduced with 100 µmol/kg dose.

CONCLUSION

H₂S shows protective effect against acute renal injury linked to APAP. This protective effect reduces with high doses of H₂S. The anti-inflammatory and antioxidant activity of H₂S may play a role in the renoprotective effect.

Optimising the use of medicines to reduce acute kidney injury in children and babies

The majority of medications in children are administered in an unlicensed or off-label manner. Paediatricians are obliged to prescribe using the limited evidence available. The 2007 EU regulation on the use of paediatric drugs means pharmaceutical companies are now obliged to (and receive incentives for) contributing to paediatric drug data and carrying out paediatric clinical trials. This is important, as the efficacy and adverse effect profiles of medicines vary across childhood. Additionally, there are significant age-related changes in the pharmacodynamic and pharmacokinetic activity of many drugs. This may be related to physiological (differential expressions of cytochrome P450 enzymes or variable glomerular filtration rates at different ages for example) and psychological (increasing autonomy and risk perception in teenage years) changes. Increasing numbers of children are surviving life-threatening childhood conditions due to medical advances. This means there is an increasing population who are at risk of the consequences of the long-term, early exposure to nephrotoxic agents. The kidney is an organ that is particularly vulnerable to damage as a consequence of drugs. Drug-induced acute kidney injury (AKI) episodes in children and babies are principally due to non-steroidal anti-inflammatory drugs, antibiotics or chemotherapeutic agents. The renal tubules are vulnerable to injury because of their concentrating ability and high-energy hypoxic environment. This review focuses on drug-induced AKI and the methods to minimise its effect, including general management plus the role of child-specific pharmacokinetic data, the use of pharmacogenomics and early detection of AKI using urinary biomarkers and electronic triggers.

Mitochondria-Targeted Antioxidants: Future Perspectives in Kidney Ischemia Reperfusion Injury

Kidney ischemia/reperfusion injury emerges in various clinical settings as a great problem complicating the course and outcome. Ischemia/reperfusion injury is still an unsolved puzzle with a great diversity of investigational approaches, putting the focus on oxidative stress and mitochondria. Mitochondria are both sources and targets of ROS. They participate in initiation and progression of kidney ischemia/reperfusion injury linking oxidative stress, inflammation, and cell death. The dependence of kidney proximal tubule cells on oxidative mitochondrial metabolism makes them particularly prone to harmful effects of mitochondrial damage. The administration of antioxidants has been used as a way to prevent and treat kidney ischemia/reperfusion injury for a long time. Recently a new method based on mitochondria-targeted antioxidants has become the focus of interest. Here we review the current status of results achieved in numerous studies investigating these novel compounds in ischemia/reperfusion injury which specifically target mitochondria such as MitoQ, Szeto-Schiller (SS) peptides (Bendavia), SkQ1 and SkQR1, and superoxide dismutase mimics. Based on the favorable results obtained in the studies that have examined myocardial ischemia/reperfusion injury, ongoing clinical trials investigate the efficacy of some novel therapeutics in preventing myocardial infarct. This also implies future strategies in preventing kidney ischemia/reperfusion injury.

N-acetylcysteine reduces the renal oxidative stress and apoptosis induced by hemorrhagic shock

BACKGROUND

Renal ischemia/reperfusion injury induced by hemorrhagic shock (HS) and subsequent fluid resuscitation is a common cause of acute renal failure. The objective of this study was to evaluate the effect of combining N-acetylcysteine (NAC) with fluid resuscitation on renal injury in rats that underwent HS.

MATERIALS AND METHODS

Two groups of male Wistar rats were induced to controlled HS at 35 mm Hg mean arterial pressure for 60 min. After this period, the HS and fluid resuscitation (HS/R) group was resuscitated with lactate containing 50% of the blood that was withdrawn. The HS/R + NAC group was resuscitated with Ringer's lactate combined with 150 mg/kg of NAC and blood. The sham group animals were catheterized but were not subjected to shock. All animals were kept under anesthesia and euthanized after 120 min of fluid resuscitation or observation.

RESULTS

Animals treated with NAC presented attenuation of histologic lesions, reduced oxidative stress, and apoptosis markers when compared with animals from the HS/R group. The serum creatinine was similar in all the groups.

CONCLUSIONS

NAC is a promising drug for combining with fluid resuscitation to attenuate the kidney injury associated with HS.

Drug-induced acute kidney injury in children

Acute kidney injury (AKI) is a serious problem occurring in anywhere between 8 and 30% of children in the intensive care unit. Up to 25% of these cases are believed to be the result of pharmacotherapy. In this review we have focused on several relevant drugs and/or drug classes, which are known to cause AKI in children, including cancer chemotherapeutics, non-steroidal anti-inflammatory drugs and antimicrobials. AKI demonstrates a steady association with increased long term risk of poor outcomes including chronic kidney disease and death as determined by the extent of injury. For this reason it is important to understand the causality and implications of these drugs and drug classes. Children occupy a unique patient population, advocating the importance of understanding how they are affected dissimilarly compared with adults. While the kidney itself is likely more susceptible to injury than other organs, the inherent toxicity of these drugs also plays a major role in the resulting AKI. Mechanisms involved in the toxicity of these drugs include oxidative damage, hypersensitivity reactions, altered haemodynamics and tubule obstruction and may affect the glomerulus and/or the tubules. Understanding these mechanisms is critical in determining the most effective strategies for treatment and/or prevention, whether these strategies are less toxic versions of the same drugs or add-on agents to mitigate the toxic effect of the existing therapy.

N-acetyl-cysteine is associated to renal function improvement in patients with nephropathic cystinosis

BACKGROUND

Nephropathic cystinosis is an autosomal recessive systemic severe disease characterized by intralysosomal cystine storage. Cysteamine is an essential component of treatment. There is solid evidence that cystine accumulation itself is not responsible for all abnormalities in cystinosis; there is also a deficiency of glutathione in the cytosol. Patients with cystinosis can be more susceptible to oxidative stress.

CASE-DIAGNOSIS/TREATMENT

The patient cohort comprised 23 cystinosis patients (16 males) aged <18 years (mean age 8.0 ± 3.6 years) with chronic kidney disease class I-IV with good adherence to treatment, including cysteamine. Oxidative stress was evaluated based on the levels of serum thiobarbituric acid-reactive substances (TBARS), and renal function was evaluated based on serum creatinine and cystatin C levels and creatinine clearance (Schwartz formula). N-Acetylcysteine (NAC), an antioxidant drug was given to all patients for 3 months (T1) at 25 mg/kg/day divided in three doses per day. The measured values at just before the initiation of NAC treatment (T0) served as the control for each patient.

RESULTS

Median serum TBARS levels at T0 and T1 were 6.92 (range 3.3-29.0) and 1.7 (0.6-7.2)  nmol/mL, respectively (p < 0.0001). In terms of renal function at T0 and T1, serum creatinine levels (1.1 ± 0.5 vs. 0.9 ± 0.5 mg/dL, respectively; p < 0.0001), creatinine clearance (69.7 ± 32.2 vs. T1 = 78.5 ± 33.9 mL/min/1.73 m(2), respectively; p = 0.006), and cystatin c level (1.33 ± 0.53 vs. 1.15 ± 0.54 mg/l, respectively; p = 0.0057) were all significantly different at these two time points. Serum creatinine measurements at 6 (T -6) and 3 months (T -3) before NAC initiation and at 3 (T +3) and 6 months (T +6) after NAC had been withdrawn were also evaluated.

CONCLUSION

During the 3-month period that our 23 cystinosis patients were treated with NAC, oxidative stress was reduced and renal function significantly improved. No side-effects were detected. Larger and controlled studies are needed to confirm these findings.

Role of progesterone in melatonin-mediated protection against acute kidney injury

BACKGROUND

Melatonin is released by pineal gland and maintains circadian rhythm in the body. It has been reported as renoprotective agent because of its antioxidant property. Recently, a cross talk between progesterone and melatonin has been observed in various preclinical studies. The present study investigated the involvement of progesterone receptors in melatonin-mediated protection against ischemia reperfusion induced acute kidney injury (AKI) in rats.

MATERIALS AND METHODS

The rats were subjected to bilateral renal ischemia for 40 min followed by reperfusion for 24 h to induce AKI. The AKI was assessed by measuring creatinine clearance, serum urea, uric acid level, potassium level, fractional excretion of sodium, lactate dehydrogenase activity, and microproteinuria. The oxidative stress in renal tissues was assessed by quantification of myeloperoxidase activity, thiobarbituric acid reactive substances, superoxide anion generation, reduced glutathione level, and catalase activity. The hematoxylin-eosin staining was carried out to observe histopathologic changes in renal tissues. The melatonin (4 and 10 mg/kg, intraperitoneally) and progesterone receptor antagonist mifepristone (5 mg/kg, intraperitoneally) were used in the present study.

RESULTS

The renal ischemia reperfusion induced AKI as indicated by significant change in serum, urinary, and tissue parameters that was ameliorated by prior treatment with melatonin. No significant difference in serum progesterone level was observed between various groups used in the present study. The prior administration of mifepristone abolished melatonin-mediated protection against AKI.

CONCLUSIONS

It is concluded that melatonin treatment affords protection against ischemia reperfusion induced AKI. Moreover, progesterone receptors are essentially involved in mediating protective role of melatonin against AKI in rats.

Pharmacogenomics and adverse drug reactions in children

Adverse drug reactions are a common and important complication of drug therapy in children. Over the past decade it has become increasingly apparent that genetically controlled variations in drug disposition and response are important determinants of adverse events for many important adverse events associated with drug therapy in children. While this research has been difficult to conduct over the past decade technical and ethical evolution has greatly facilitated the ability of investigators to conduct pharmacogenomic studies in children. Some of this research has already resulted in changes in public policy and clinical practice, for example in the case of codeine use by mothers and children. It is likely that the use of pharmacogenomics to enhance drug safety will first be realized among selected groups of children with high rates of drug use such as children with cancer, but it also likely that this research will be extended to other groups of children who have high rates of drug utilization and as well as providing insights into the mechanisms and pathophysiology of adverse drug reactions in children.

Neutrophil gelatinase associated lipocalin in acute kidney injury

BACKGROUND

Neutrophil gelatinase-associated lipocalin (NGAL) is a member of the lipocalin family of proteins. Usually, NGAL is produced and secreted by kidney tubule cells at low levels, but the amount produced and secreted into the urine and serum increases dramatically after ischemic, septic, or nephrotoxic injury of the kidneys. The purpose of our review article is to summarize the role of NGAL in acute kidney injury (AKI), emergent, and intensive care.

METHODS

A PubMed search was performed (only English-language articles concerning human subjects were considered) using each of the following search term combinations: neutrophil gelatinase-associated lipocalin OR NGAL and acute kidney injury OR AKI; cardiac surgery; heart failure OR cardiology; intensive care; emergency department OR emergency medicine; nephropathy OR nephrotoxicity and transplantation.

RESULTS

The results of our search yielded 339 articles. Of the 339 articles, 160 were eligible for review based on the predefined criteria for inclusion.

CONCLUSION

Based on the evidence reviewed, it is clear that patient NGAL level is an appropriate, sensitive, and specific early biomarker of AKI caused by a variety of different etiologies. It is advised that a multidisciplinary group of experts come together to make recommendations and propose a consensus of clinical procedures to advance the most efficacious NGAL monitoring protocol for early detection and treatment of patients with AKI.

Pharmacogenomics in children

Historically genetics has not been considered when prescribing drugs for children. However, it is clear that genetics are not only an important determinant of disease in children but also of drug response for many important drugs that are core agents used in the therapy of common problems in children. Advances in therapy and in the ethical construct of children's research have made pharmacogenomic assessment for children much easier to pursue. It is likely that pharmacogenomics will become part of the therapeutic decision making process for children, notably in areas such as childhood cancer where the benefits and risks of therapy are considerable.

New ways to detect adverse drug reactions in pediatrics

Adverse drug reactions (ADRs) complicate at least 5% of all courses of therapy for children. Dealing with an ADR requires a stepwise approach in appreciation of the possibility of an ADR, assessment of whether the adverse event in question is drug-related, assessment of causality, assistance in treating the symptoms of the ADR, and dealing with the aftermath of the event. Several new developments likely will improve the ability to assess, evaluate, treat, and prevent ADRs in children. These developments include tools to evaluate causality, laboratory tests to diagnose ADRs, pharmacogenomic approaches to prevent ADRs, and new insights into treating serious ADRs.