ADVERSE REACTIONS OF NITROFURANTOIN, TRIMETHOPRIM AND SULFAMETHOXAZOLE IN CHILDREN

Anticancer therapy-induced adverse drug reactions in children and preventive and control measures

In recent years, considerable achievements have been made in pediatric oncology with the innovation and development of antitumor drugs. However, compared to adults, children as a special group have not yet matured fully in terms of liver and kidney function. Moreover, pediatric patients are prone to more adverse drug reactions (ADRs) from the accumulation of antineoplastic drugs due to their smaller body size and larger body surface area. Chemotherapy-related ADRs have become a non-negligible factor that affects cancer remission. To date, studies on ADRs in pediatric cancer patients have emerged internationally, but few systematic summaries are available. Here, we reviewed the various systemic ADRs associated with antitumor drugs in children and adolescent patients, as well as the advances in strategies to cope with ADRs, which consisted of neurotoxicity, hematological toxicity, cardiotoxicity, ADRs of the respiratory system and gastrointestinal system and urinary system, ADRs of the skin and its adnexa, allergic reactions, and other ADRs. For clinicians and researchers, understanding the causes, symptoms, and coping strategies for ADRs caused by anticancer treatments will undoubtedly benefit more children.

Insight into the mechanism and toxicology of nitrofurantoin: a metabolomics approach

Safety and effectiveness are the two ends of the balance in drug development that needs to be evaluated. The biotransformation of drugs within a living organism could potentiate biochemical insults in the tissue and compromise the safety of drugs. Nitrofurantoin (NFT) is a cheap clinical antibiotic with a wide array of activities against gram-positive and gram-negative organisms. The NFT scaffold has been utilized to develop other derivates or analogues in the quest to repurpose drugs against other infectious diseases. Several techniques were developed over the years to study the mechanism of NFT metabolism and toxicity, such as voltammetry, chromatographic analysis, protein precipitation, liquid-liquid extraction, etc. Due to limitations in these methods, the mechanism of NFT biotransformation in the cell is poorly understood. Metabolomics has been adopted in drug metabolism to understand the mechanism of drug toxicity and could provide a solution to overcome the limitations of current techniques to determine mechanisms of toxicity. Unfortunately, little or no information regarding the metabolomics approach in NFT metabolism and toxicity is available. Hence, this review highlights the metabolomic techniques that can be adopted in NFT metabolism and toxicological studies to encourage the research community to widely adopt and utilize metabolomics in understanding NFT's metabolism and toxicity.

Frequency of drug-induced liver injury in children receiving anti-staphylococcal penicillins

INTRODUCTION

Anti-staphylococcal penicillins (ASPs) are among the most commonly prescribed antibiotics in children and are associated with a risk of drug-induced liver injury (DILI). Despite the frequent use of ASPs in children, there is no consensus on whether liver function tests (LFTs) should be routinely monitored during treatment.

OBJECTIVES

To review the literature on the frequency of ASP-related DILI in children to determine the incidence, risk factors and outcomes of hepatotoxicity.

METHODS

PubMed, MEDLINE and Embase were searched in January 2022 for original studies of children who received cloxacillin, dicloxacillin, flucloxacillin, methicillin, nafcillin or oxacillin that included ≥10 children aged up to 18 years, and presented data on the incidence of DILI in children exposed to ASPs.

RESULTS

Overall, two studies of oral flucloxacillin, two of intravenous (IV) methicillin, three of IV nafcillin and four of IV oxacillin were included. The mean onset of DILI ranged between 7.0 and 19.0 days following commencement of antibiotic treatment and all episodes resolved between 14.2 and 16.0 days after drug discontinuation, with no specific treatment required. This review found that the incidence of DILI in children was 1 in 50 000 for oral flucloxacillin and ranged from 1 in 3 to 13 for IV oxacillin, methicillin and nafcillin.

CONCLUSIONS

This review found that routine LFT monitoring is not required in children receiving low dose oral flucloxacillin in a primary care setting, although pharmacovigilance is critical. For IV preparations, the existing data support routine LFT monitoring in those receiving treatment for at least 7 days.

Antibiotics and the Nervous System-Which Face of Antibiotic Therapy Is Real, Dr. Jekyll (Neurotoxicity) or Mr. Hyde (Neuroprotection)?

Antibiotics as antibacterial drugs have saved many lives, but have also become a victim of their own success. Their widespread abuse reduces their anti-infective effectiveness and causes the development of bacterial resistance. Moreover, irrational antibiotic therapy contributes to gastrointestinal dysbiosis, that increases the risk of the development of many diseases, including neurological and psychiatric. One of the potential options for restoring homeostasis is the use of oral antibiotics that are poorly absorbed from the gastrointestinal tract (e.g., rifaximin alfa). Thus, antibiotic therapy may exert neurological or psychiatric adverse drug reactions which are often considered to be overlooked and undervalued issues. Drug-induced neurotoxicity is mostly observed after beta-lactams and quinolones. Penicillin may produce a wide range of neurological dysfunctions, including encephalopathy, behavioral changes, myoclonus or seizures. Their pathomechanism results from the disturbances of gamma-aminobutyric acid-GABA transmission (due to the molecular similarities between the structure of the β-lactam ring and GABA molecule) and impairment of the functioning of benzodiazepine receptors (BZD). However, on the other hand, antibiotics have also been studied for their neuroprotective properties in the treatment of neurodegenerative and neuroinflammatory processes (e.g., Alzheimer's or Parkinson's diseases). Antibiotics may, therefore, become promising elements of multi-targeted therapy for these entities.

Reversible lung fibrosis in a 6-year-old girl after long term nitrofurantoin treatment

Background

Pulmonary side effects are well known, including lung fibrosis, in elderly patients treated with long-term nitrofurantoin to prevent urinary tract infections and secondary renal injury. However, pulmonary side effects have only been reported rarely in paediatric cases, despite nitrofurantoin being a first line prophylactic treatment of recurrent childhood urinary tract infection.

Case presentations

A 6-year-old girl was admitted to the hospital with dyspnea, general fatigue, loss of appetite and need for nasal oxygen treatment after long-term nitrofurantoin treatment. A computed tomography scan of the chest showed lung fibrosis. A biopsy confirmed this diagnosis. We suspected the fibrosis to be caused by the nitrofurantoin treatment. Thorough examinations reveal no other explanations. Nitrofurantoin was discontinued and the girl was treated with methylprednisolone. After 17 month a new scan and lung function test showed total regression of the lung fibrosis.

Conclusions

This case underlines that risk of severe side effects should be taken in to account before initiation of long-term nitrofurantoin treatment in children.

International consensus validation of the POPI tool (Pediatrics: Omission of Prescriptions and Inappropriate prescriptions) to identify inappropriate prescribing in pediatrics

INTRODUCTION

While drug prescription should be based on established recommendations stemming from clinical trials but in pediatrics, many drugs are used without marketing authorization. Consequently recommendations are often based on clinical experience and the risk of inappropriate prescription (IP) is high. A tool for detecting IP in pediatrics-called POPI (Pediatrics: Omission of Prescriptions and Inappropriate prescriptions)-has been developed in France. However the relevance of its use at an international level is not known. Our aim has been to adapt POPI for a worldwide use.

MATERIAL AND METHOD

A two-round Delphi online questionnaire was completed and validated by international experts to identify consensual items. They were asked to rate the validity of each items taking into account the recommendations and practices in their countries. Only propositions obtaining a median score in the upper tertile with an agreement of more than 75% of the panel-for the first round-and 85%-for the second round-were retained.

RESULTS

Our panel included 11 pharmacists (55%) and 9 physicians (45%). The panelists came from 12 different countries: England, Belgium, Brazil, Canada, China, Ivory Coast, Ireland, Malaysia, Portugal, Switzerland, Turkey and Vietnam. At the end of the first round, of the 105 items of the original POPI tool, 80 items were retained including 16 items reworded and 25 items were deleted. In the second round, 14 experts participated in the study. This final international POPI tool is composed of 73 IP and omissions of prescriptions in the fields of neuropsychiatry, dermatology, infectiology, pneumology, gastroenterology, pain and fever.

DISCUSSION AND CONCLUSION

This study highlights international consensus on prescription practice in pediatrics. The use of this tool in everyday practice could reduce the risk of inappropriate prescription. The impact of the diffusion of POPI tool will be assessed in a prospective multicentric study.

Effect of kitasamycin and nitrofurantoin at subinhibitory concentrations on quorum sensing regulated traits of Chromobacterium violaceum

Quorum sensing (QS) is a mechanism of intercellular communication in bacteria that received substantial attention as alternate strategy for combating bacterial resistance and the development of new anti-infective agents. The present investigation reports on the assessment of using subinhibitory concentrations of antibiotics for the inhibition of QS-regulated phenotypes in Chromobacterium violaceum. Primarily, the minimum inhibitory concentrations of a series of antibiotics were determined by a microdilution method. Subsequently, the inhibitory effects of selected antibiotics on QS-regulated traits, namely violacein and chitinase production, biofilm formation and motility were evaluated using C. violaceum CV026 and C. violaceum ATCC 12472. Results revealed that kitasamycin and nitrofurantoin exhibited the highest quorum sensing inhibitory (QSI) activity. The amount of violacein produced by C. violaceum was significantly reduced in the presence of either kitasamycin or nitrofurantoin. Moreover, the chitinolytic activity, biofilm formation, and motility were also impaired in kitasamycin or nitrofurantoin-treated cultures. We further confirmed QSI effects at the molecular level using molecular docking and real-time quantitative polymerase chain reaction (RT-qPCR). Results of molecular docking suggested that both antibiotics can interact with CviR transcriptional regulator of C. violaceum. Furthermore, RT-qPCR revealed the suppressive effect of kitasamycin and nitrofurantoin on five genes under the control of the CviI/CviR system: cviI, cviR, vioB, vioC, and vioD. Giving that kitasamycin and nitrofurantoin are being safely used for decades, this study emphasizes their potential application as antivirulence agents to disarm resistant bacterial strains, making their removal an easier task for the immune system or for another antibacterial agent.

Trimethoprim-Sulfamethoxazole Associated Drug-Induced Liver Injury in Pediatrics: A Systematic Review

BACKGROUND

Drug-induced liver injury (DILI) is a rare but known adverse event associated with trimethoprim-sulfamethoxazole (TMP-SMX) in adults. No studies to date have looked at the risk of this association in children. We systematically reviewed the evidence for a potential association between TMP-SMX and DILI in the pediatric population.

METHODS

PubMed, Medline, Embase, Cochrane Database of Systematic Reviews, Scopus and Web of Science was searched using a combination of terms to identify reports of TMP-SMX exposure, liver injury and pediatrics (≤18 years old). We included any studies with hepatic adverse events occurring after exposure to TMP-SMX. Bibliographies were reviewed for additional relevant references. The Narajno scale was used to assess causality in case studies.

RESULTS

A total of 22 studies were identified: 3 randomized trials, 1 prospective observational study, 8 retrospective observational studies and 10 case reports. Among the randomized trials and prospective studies, only mild, transient hepatic function abnormalities were reported. Retrospective observational studies reported 1 fatal DILI and statistically significant increased odds of DILI with TMP-SMX use compared with nonuse. Among the 10 case reports, severe liver outcomes and mild hepatic function abnormalities were both reported. Naranjo scores suggested reported hepatic adverse events were probably because of exposure in 5, possible in 4, and doubtful in 1 case report.

CONCLUSIONS

Evidence regarding DILI associated with TMP-SMX exposure in pediatrics is limited. Observational population studies show mild hepatic abnormalities. Case reports suggest more severe manifestations of DILI. Additional studies may reveal the association between TMP-SMX and DILI in pediatrics.

Physiologically Based Pharmacokinetic Modeling for Trimethoprim and Sulfamethoxazole in Children

OBJECTIVE

The aims of this study were to (1) determine whether opportunistically collected data can be used to develop physiologically based pharmacokinetic (PBPK) models in pediatric patients; and (2) characterize age-related maturational changes in drug disposition for the renally eliminated and hepatically metabolized antibiotic trimethoprim (TMP)-sulfamethoxazole (SMX).

METHODS

We developed separate population PBPK models for TMP and SMX in children after oral administration of the combined TMP-SMX product and used sparse and opportunistically collected plasma concentration samples to validate our pediatric model. We evaluated predictability of the pediatric PBPK model based on the number of observed pediatric data out of the 90% prediction interval. We performed dosing simulations to target organ and tissue (skin) concentrations greater than the methicillin-resistant Staphylococcus aureus (MRSA) minimum inhibitory concentration (TMP 2 mg/L; SMX 9.5 mg/L) for at least 50% of the dosing interval.

RESULTS

We found 67-87% and 71-91% of the observed data for TMP and SMX, respectively, were captured within the 90% prediction interval across five age groups, suggesting adequate fit of our model. Our model-rederived optimal dosing of TMP at the target tissue was in the range of recommended dosing for TMP-SMX in children in all age groups by current guidelines for the treatment of MRSA.

CONCLUSION

We successfully developed a pediatric PBPK model of the combination antibiotic TMP-SMX using sparse and opportunistic pediatric pharmacokinetic samples. This novel and efficient approach has the potential to expand the use of PBPK modeling in pediatric drug development.

Efficacy of Probiotic Prophylaxis After The First Febrile Urinary Tract Infection in Children With Normal Urinary Tracts

BACKGROUND

Growing antibiotic resistance and debates over their efficacy for urinary tract infection (UTI) recurrence warrants studying nonantibiotic prophylaxis for preventing UTI recurrences.

METHODS

We randomly assigned 181 children, aged 4 months to 5 years, with a normal urinary tract after recovery from their first febrile UTI in a 1:1 ratio to receive a probiotic mixture of Lactobacillus acidophilus, Lactobacillus rhamnosus, Bifidobacterium bifidum, and Bifidobacterium lactis (n = 91) or placebo (n = 90) for a total of 18 months of therapy. The primary objective was to show the superiority of probiotic prophylaxis to placebo. The primary end point was composite cure (UTI-free survival) at 18 months, and the secondary end point was the median time to first UTI recurrence.

RESULTS

The probiotics were superior to placebo with respect to the primary efficacy end point. At 18 months, composite cure was observed in 96.7% (3 of 91) of the patients in the probiotic group and 83.3% (15 of 90) of those in the placebo group (P = .02). The median time to the first incidence of UTI recurrence was 3.5 months (range, 1-4 months) and 6.5 months (range, 2-14 months) in the probiotic and placebo groups, respectively (P = .04). The main microorganism that caused recurrent UTI was Escherichia coli, followed by Klebsiella pneumoniae, and these results were not significantly different between the 2 groups. We found no specific adverse events among the participants who received the probiotic mixture during the course of therapy.

CONCLUSIONS

The probiotics were more effective than placebo at reducing the risk of recurrent UTI in children with a normal urinary tract after their first episode of febrile UTI.

Laboratory Findings After Urinary Tract Infection and Antimicrobial Prophylaxis in Children With Vesicoureteral Reflux

It is a common practice to monitor blood tests in patients receiving long-term trimethoprim-sulfamethoxazole (TMP-SMZ) prophylaxis for recurrent urinary tract infections. This multicenter, randomized, placebo-controlled trial enrolled 607 children aged 2 to 71 months with vesicoureteral reflux diagnosed after symptomatic urinary tract infection. Study participants received TMP-SMZ (n = 302) or placebo (n = 305) and were followed for 2 years. Serum electrolytes (n ≥ 370), creatinine (n = 310), and complete blood counts (n ≥ 206) were measured at study entry and at the 24-month study conclusion. We found no significant electrolyte, renal, or hematologic abnormalities when comparing the treatment and placebo groups. We observed changes in several laboratory parameters in both treatment and placebo groups as would normally be expected with physiologic maturation. Changes were within the normal range for age. Long-term use of TMP-SMX had no treatment effect on complete blood count, serum electrolytes, or creatinine. Our findings do not support routine monitoring of these laboratory tests in children receiving long-term TMP-SMZ prophylaxis.

Characterizing Patients with Recurrent Urinary Tract Infections in Vesicoureteral Reflux: A Pilot Study of the Urinary Proteome

Recurrent urinary tract infections (UTIs) pose a significant burden on the health care system. Underlying mechanisms predisposing children to UTIs and associated changes in the urinary proteome are not well understood. We aimed to investigate the urinary proteome of a subset of children who have vesicoureteral reflux (VUR) and recurrent UTIs because of their risk of developing infection-related renal damage. Improving diagnostic modalities to identify UTI risk factors would significantly alter the clinical management of children with VUR. We profiled the urinary proteomes of 22 VUR patients with low grade VUR (1-3 out of 5), a history of recurrent UTIs, and renal scarring, comparing them to those obtained from 22 age-matched controls. Urinary proteins were analyzed by mass spectrometry followed by protein quantitation based on spectral counting. Of the 2,551 proteins identified across both cohorts, 964 were robustly quantified, as defined by meeting criteria with spectral count (SC) ≥2 in at least 7 patients in either VUR or control cohort. Eighty proteins had differential expression between the two cohorts, with 44 proteins significantly up-regulated and 36 downregulated (q <0.075, FC ≥1.2). Urinary proteins involved in inflammation, acute phase response (APR), modulation of extracellular matrix (ECM), and carbohydrate metabolism were altered among the study cohort.

Review of the pharmacokinetic properties of nitrofurantoin and nitroxoline

Nitrofurantoin and nitroxoline are oral antibiotics for the treatment or prophylaxis of acute urinary tract infections. New interest in both these drugs is increasing because of the emergence of resistance to other antibiotics, but knowledge of their pharmacokinetics (PK) is lacking since they were developed before the advent of standardized research for drug approval. The aims of this review were to (i) summarize the PK data reported in the literature and (ii) to identify PK knowledge gaps. The current body of PK knowledge of both drugs appears to be poor and mainly based on old studies. Nitrofurantoin PK values were obtained from studies using many variables, e.g. formulations, crystal sizes and analytical methods, resulting in high interindividual variability in PK parameters and no uniform PK profile. Clinical experience and PK data for nitroxoline are even more limited since the drug is registered in only Germany and a few (Eastern European) countries. Clinical studies in relevant patient populations are needed with commercially available nitrofurantoin and nitroxoline formulations at approved dosing regimens to more fully characterize their PK profiles, and to investigate the influence of patient characteristics on these profiles in order to optimize efficacy and avoid toxicity and emergence of resistance. Only with this updated knowledge and efficacy data from well-structured trials can both drugs maintain their antimicrobial activity against uropathogens.

Incidence of Pneumocystis jirovecii and Adverse Events Associated With Pneumocystis Prophylaxis in Children Receiving Glucocorticoids

BACKGROUND

Antimicrobial prophylaxis is indicated to prevent Pneumocystis jirovecii pneumonia (PJP) in profoundly immunosuppressed children. The incidence of PJP infection in children with chronic glucocorticoid exposure is unknown, and PJP prophylaxis has been associated with adverse events. We hypothesized that PJP infection is rare in children without human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS), cancer, or a transplant history who are using chronic glucocorticoids and that those exposed to PJP prophylaxis are more likely to experience a cutaneous hypersensitivity reaction or myelosuppression than unexposed patients.

METHODS

This study involved a retrospective cohort from the Clinformatics Data Mart Database (OptumInsight, Eden Prairie, MN). We identified patients ≤18 years of age who received at least 2 prescriptions for a systemic glucocorticoid within a 60-day period and excluded patients with a history of PJP infection, an oncologic diagnosis, transplant, or HIV/AIDS. PJP prophylaxis exposure was identified by using national drug codes. Cutaneous hypersensitivity reaction or myelosuppression was identified by using International Classification of Diseases, 9th Revision (ICD-9), codes. We used a discrete time-failure model to examine the association between exposure and outcome.

RESULTS

We identified 119399 children on glucocorticoids, 10% of whom received PJP prophylaxis. The incidences of PJP were 0.61 and 0.53 per 10000 patient-years in children exposed and those unexposed to PJP prophylaxis, respectively. In a multivariable model, trimethoprim-sulfamethoxazole was associated with cutaneous hypersensitivity reaction (odds ratio, 3.20; 95% confidence interval, 2.62-3.92) and myelosuppression (odds ratio, 1.85; 95% confidence interval, 1.56-2.20).

CONCLUSIONS

PJP infection was rare in children using glucocorticoids chronically, and PJP prophylaxis-associated cutaneous hypersensitivity reactions and myelosuppression are more common. The use of PJP chemoprophylaxis in children without HIV/AIDS, cancer, or a transplant history who are taking glucocorticoids chronically should be considered carefully.

Drug-Induced Liver Injury in Children: Clinical Observations, Animal Models, and Regulatory Status

Drug-induced liver injury in children (cDILI) accounts for about 1% of all reported adverse drug reactions throughout all age groups, less than 10% of all clinical DILI cases, and around 20% of all acute liver failure cases in children. The overall DILI susceptibility in children has been assumed to be lower than in adults. Nevertheless, controversial evidence is emerging about children's sensitivity to DILI, with children's relative susceptibility to DILI appearing to be highly drug-specific. The culprit drugs in cDILI are similar but not identical to DILI in adults (aDILI). This is demonstrated by recent findings that a drug frequently associated with aDILI (amoxicillin/clavulanate) was rarely associated with cDILI and that the drug basiliximab caused only cDILI but not aDILI. The fatality in reported cDILI studies ranged from 4% to 31%. According to the US Food and Drug Administration-approved drugs labels, valproic acid, dactinomycin, and ampicillin appear more likely to cause cDILI. In contrast, deferasirox, isoniazid, dantrolene, and levofloxacin appear more likely to cause aDILI. Animal models have been explored to mimic children's increased susceptibility to valproic acid hepatotoxicity or decreased susceptibility to acetaminophen or halothane hepatotoxicity. However, for most drugs, animal models are not readily available, and the underlying mechanisms for the differential reactions to DILI between children and adults remain highly hypothetical. Diagnosis tools for cDILI are not yet available. A critical need exists to fill the knowledge gaps in cDILI. This review article provides an overview of cDILI and specific drugs associated with cDILI.

Predicting neurological Adverse Drug Reactions based on biological, chemical and phenotypic properties of drugs using machine learning models

Adverse drug reactions (ADRs) have become one of the primary reasons for the failure of drugs and a leading cause of deaths. Owing to the severe effects of ADRs, there is an urgent need for the generation of effective models which can accurately predict ADRs during early stages of drug development based on integration of various features of drugs. In the current study, we have focused on neurological ADRs and have used various properties of drugs that include biological properties (targets, transporters and enzymes), chemical properties (substructure fingerprints), phenotypic properties (side effects (SE) and therapeutic indications) and a combinations of the two and three levels of features. We employed relief-based feature selection technique to identify relevant properties and used machine learning approach to generated learned model systems which would predict neurological ADRs prior to preclinical testing. Additionally, in order to explain the efficiency and applicability of the models, we tested them to predict the ADRs for already existing anti-Alzheimer drugs and uncharacterized drugs, respectively in side effect resource (SIDER) database. The generated models were highly accurate and our results showed that the models based on chemical (accuracy 93.20%), phenotypic (accuracy 92.41%) and combination of three properties (accuracy 94.18%) were highly accurate while the models based on biological properties (accuracy 82.11%) were highly informative.

Contemporary Management of Vesicoureteral Reflux

The past 30 years have seen broad changes in the diagnosis and management of vesicoureteral reflux (VUR). Recently, a clinical debate has generated an open discussion in academic circles. New evidence has shifted treatment patterns away from widespread surgical management and recently brought into question some pharmacologic treatments. VUR is usually not hazardous by itself but is a significant risk factor for urinary tract infection (UTI) and less commonly, renal scarring and insufficiency. Given the costs and morbidity of UTI as well as the potential for significant renal injury, our approach remains conservative. Careful follow-up, parental education about pathophysiology and management of VUR and UTI, and management of bowel and bladder dysfunction (BBD) when present, are the foundation of treatment. Additionally, though we recognize the limitation of continuous antibiotic prophylaxis (CAP), we believe the benefits outweigh the risks and costs for many patients. Careful observation can be considered in patients with a single medical home, parental understanding of what UTI signs and symptoms are, low grade VUR, no history of complicated UTIs and close follow-up. Surgical management remains a relevant option for select patients who fail conservative measures with breakthrough UTIs or failure to resolve. Minimally invasive surgical options are available with acceptable outcomes though open ureteroneocystostomy still carries the highest success rate.

Recurrent urinary tract infections in children: Preventive interventions other than prophylactic antibiotics

Urinary tract infection (UTI) is one of the most common childhood infections. Permanent renal cortical scarring may occur in affected children, especially with recurrent UTIs, leading to long-term complications such as hypertension and chronic renal failure. To prevent such damage, several interventions to prevent UTI recurrences have been tried. The most established and accepted prevention at present is low dose long-term antibiotic prophylaxis. However it has a risk of break through infections, adverse drug reactions and also the risk of developing antibiotic resistance. The search is therefore on-going to find a safer, effective and acceptable alternative. A recent meta-analysis did not support routine circumcision for normal boys with no risk factors. Vaccinium Macrocarpon (cranberry), commonly used against UTI in adult women, is also effective in reducing the number of recurrences and related antimicrobial use in children. Sodium pentosanpolysulfate, which prevents bacterial adherence to the uroepithelial cells in animal models, has shown conflicting results in human trials. When combined with antibiotic, Lactobacillus acidophilus (LA-5) and Bifidobacterium, by blocking the in vitro attachment of uropathogenic bacteria to uroepithelial cells, significantly reduce in the incidence of febrile UTIs. Deliberate colonization of the human urinary tract of patients with recurrent UTI with Escherichia-coli (E. coli) 83972 has resulted in subjective benefit and less UTI requiring treatment. The non-pathogenic E. coli isolate NU14 DeltawaaL is a candidate to develop live-attenuated vaccine for the treatment and prevention of acute and recurrent UTI. Diagnosing and treating dysfunctional elimination syndromes decrease the incidence of recurrent UTI. A meta-analysis found the lack of robust prospective randomized controlled trials limited the strength of the established guidelines for surgical management of vesicoureteral reflux. In conclusion, several interventions, other than antibiotic prophylaxis, for the prevention of recurrent UTI have been tried and, although showing some promise, they do not provide so far a definitive effective answer. Finding suitable alternatives still requires further high quality research of those seemingly promising interventions.

Predictive risk factors in childhood urinary tract infection, vesicoureteral reflux, and renal scarring management

Approaches to the management of children with urinary tract infection (UTI), vesicoureteral reflux (VUR), and renal scars have been challenged and have become controversial over the past decade. It is difficult to determine when, how, and which patients will benefit from the diagnosis and management of this condition. Therefore, the issues of diagnostic imaging, observation, follow-up, and intervention tend to be decided more on a case-by-case basis, rather than by using an algorithm. Over the past few years, there have been advances in the identification of risk factors that predispose patients with UTI to present with VUR, to develop recurrent UTIs and renal scars, to have deteriorating renal function, to show VUR improvement and/or spontaneous resolution, and to be candidates for and benefit from early surgical intervention.

Antibiotic induced liver injury: what about children?

Antimicrobial agents are important causes of drug-induced liver injury. They are responsible for about 45% of cases of drug hepatotoxicity. Hepatic damage mechanisms are intrinsic or idiosyncratic. Usually, antibiotics are responsible for idiosyncratic toxicity. This review summarizes the rate of incidence and clinical features of hepatotoxicity due to antibiotics and chemotherapics, with particular attention to data regarding paediatric population. Liver injury features have been systematically evaluated for the most commonly administered antibiotics and chemotherapics in adults, even though there is little information about other widely used compounds, as cephalosporine or clarithromycin, and about antibiotics active against multi-resistant bacteria, as carbapenems, vancomycin, clindamycin, and linezolid. By contrast, there is an abundance of case reports in paediatrics, but very few structured studies have been carried out in children. Children are an important class of antibiotic users, with specific metabolic characteristics, so more studies on them should be carried out.

Influence of flocculating agents and structural vehicles on the physical stability and rheological behavior of nitrofurantoin suspension

Background:

Nitrofurantoin is a nitrofuran antibiotic that has been used for treatment of urinary tract against positive and negative bacteria.

Objectives:

The aim of this study was to evaluate the effect of structural vehicles and flocculating agents on physical stability and rheological behavior of nitrofurantoin suspension.

Materials and Methods:

To formulate the suspensions, the effect of glycerin and polysorbate 80 as wetting agents was evaluated and their particle sizes were determined using the sieve method. Then to achieve controlled flocculation, sodium citrate and aluminum chloride were added. After choosing the suitable wetting and flocculating agents, structural vehicles such as sodium carboxyl methyl cellulose and Veegum were evaluated individually and in combination. In addition, the effect of sorbitol on density of continuous phase and some physical stability parameters such as sedimentation volume, degree of flocculation and ease of redispersion of the suspensions were evaluated. After incorporation of structural vehicles, the rheological properties of formulations were also determined to find their flow behavior.

Results:

According to the results, glycerin (0.2%) and sodium citrate (0.3%) had the best effect on the suspension stability as wetting and flocculating agents, respectively. Rheological properties of formulations showed pseudoplastic behavior with some degree of thixotropy.

Conclusions:

In conclusion, the suspension containing Veegum 1%, sodium carboxy methyl cellulose 1%, glycerine 0.2%, sodium citrate 0.3% and sorbitol 20 % was chosen as the most physically stable formulation.

Hepatotoxicity induced by trimethoprim-sulfamethoxazole in a child with cystic fibrosis

Patients with cystic fibrosis (CF) have chronic and progressive lung infections with various bacterial organisms that require treatment with oral and intravenous antibiotics on a regular basis. Trimethoprim-sulfamethoxazole (TMP-SMX) is one of the medications used to treat acute pulmonary infectious exacerbations in patients with CF. Hepatic toxicity secondary to TMP-SMX was previously described in normal subjects but has not been reported in children with CF. Here we describe a 14-year-old female child with CF who was given oral TMP-SMX for an acute pulmonary infectious exacerbation. She developed a rash, severe constitutional symptoms, and significant elevation of liver enzyme concentrations secondary to immunity-mediated reaction to TMP-SMX. Discontinuation of TMP-SMX and supportive treatment led to resolution of her symptoms and normalization of liver enzyme concentrations.

Ultrasound bladder wall thickness measurement in diagnosis of recurrent urinary tract infections and cystitis cystica in prepubertal girls

OBJECTIVE

To evaluate urinary bladder wall thickness (BWT) assessed by ultrasound as a diagnostic tool for cystitis cystica.

PATIENTS AND METHODS

This was a 9-year prospective study comprising 120 prepubertal girls. Sixty subjects of whom half underwent cystoscopy represented cases while the other 60 (those with a single urinary tract infection and healthy subjects) represented controls.

RESULTS

Based on receiver operating characteristics (ROC) analysis, BWT discriminated very well between cases and controls with area under the ROC curve close to 1.0. At the optimum cut-off defined at 3.9 mm, negative predictive value (NPV) was 100% leaving no probability of cystic cystitis with BWT <3.9 mm. Positive predictive value (PPV) was also very high (95.2%), indicating only around 4.82% probability of no cystic cystitis in patients with BWT values ≥3.9 mm. BWT could also distinguish between healthy subjects and those with a cured single urinary tract infection, although discriminatory properties were moderate (area under ROC 86.7%, PPV 78.8%, NPV 85.2%).

CONCLUSION

Ultrasound mucosal bladder wall measurement is a non-invasive, simple and quite reliable method in diagnosis of cystitis cystica in prepubertal girls with recurrent urinary tract infections.

Microsomal oxidative stress induced by NADPH is inhibited by nitrofurantoin redox biotranformation

Nitrofurantoin is used in the antibacterial therapy of the urinary tract. This therapy is associated with various adverse effects whose mechanisms remain unclear. Diverse studies show that the nitro reductive metabolism of nitrofurantoin leads to ROS generation. This reaction can be catalyzed by several reductases, including the cytochrome P450 (CYP450) reductase. Oxidative stress arising from this nitro reductive metabolism has been proposed as the mechanism underlying the adverse effects associated with nitrofurantoin. There is, however, an apparent paradox between these findings and the ability of nitrofurantoin to inhibit lipid peroxidation provoked by NADPH in rat liver microsomes. This work was aimed to show the potential contribution of different enzymatic systems to the metabolism of this drug in rat liver microsomes. Our results show that microsomal lipid peroxidation promoted by NADPH is inhibited by nitrofurantoin in a concentration-dependent manner. This suggests that the consumption of NADPH in microsomes can be competitively promoted by lipid peroxidation and nitrofurantoin metabolism. The incubation of microsomes with NADPH and nitrofurantoin generated 1-aminohidantoin. In addition, the biotransformation of a classical substrate of CYP450 oxidative system was competitively inhibited by nitrofurantoin. These results suggest that nitrofurantoin is metabolized through CYP450 system. Data are discussed in terms of the in vitro redox metabolism of nitrofurantoin.

Cotrimoxazole and neonatal kernicterus: a review

Sulfamethoxazole (SMX) and trimethoprim (TMP) individually and a combination known as cotrimoxazole (SMX-TMP) are widely used for the treatment of protozoan and bacterial infections. SMX-TMP is also one of the widely used antibiotics administered orally in neonates, along with gentamicin injection, for treating pneumonia and sepsis by home-based healthcare providers in Asian countries. Although the use of this drug has successfully reduced neonate mortality, there is a concern for it causing neurotoxicity. Previous clinical studies with sulfisoxazole have demonstrated occurrence of kernicterus in neonates. This sulfonamide is thought to displace bilirubin from its albumin-binding sites in plasma leading to an elevation of plasma bilirubin, which crosses the blood-brain barrier, reaches central neurons to cause kernicterus. We performed an extensive review of clinical and animal studies with cotrimoxazole, which showed no reported incidences of kernicterus with SMX-TMP use in neonates. EndNote, BasicBiosis, Embase, PubMed and Toxline database searches were conducted using specific keywords yielding 74 full-length articles relevant to the review. This review has taken into account various factors, including the disease itself, direct effects of the drug and its metabolism through conjugation and acetylation through a thorough review of the literature to examine the potentials of SMX-TMP to cause kernicterus in neonates. SMX-TMP in oral doses administered to neonates for 7-10 days is unlikely to cause kernicterus. Also, this review recommends warranting the need of future studies using animal models and clinical studies in humans to address SMX-TMP toxicity.

Trends in adverse reactions to trimethoprim-sulfamethoxazole

OBJECTIVE

To examine temporal trends of adverse drug reactions (ADRs) associated with trimethoprim-sulfamethoxazole (TMP-SMX) use in children.

METHODS

We performed a retrospective observational study to characterize TMP-SMX ADRs in children between 2000 and 2009. We completed a chart review at our institution by identifying children diagnosed with TMP-SMX ADRs. To compare local trends to comparable institutions, we estimated the frequency of hospitalizations for TMP-SMX ADRs at 25 tertiary pediatric hospitals utilizing the Pediatric Health Information System database. To determine whether changes in outpatient prescribing rates occurred, we used the National Ambulatory Medical Care Survey/National Hospital Ambulatory Medical Care Survey.

RESULTS

At our institution, 109 children were diagnosed with a TMP-SMX ADR (5 cases from 2000 to 2004 as compared with 104 cases from 2005 to 2009). Fifty-eight percent had been treated for a skin and soft tissue infection (SSTI). A similar trend was observed nationally, where the incidence of TMP-SMX ADRs more than doubled from 2004 to 2009 at comparable pediatric hospitals (P < .001). Although national outpatient data revealed no change in overall TMP-SMX prescribing, the percentage of children prescribed TMP-SMX for SSTI sharply increased during the study period (0%-2% [2000-2004]; 9%-17% [2005-2009]).

CONCLUSIONS

The majority of TMP-SMX ADRs at our institution occurred in conjunction with SSTI treatment. TMP-SMX ADRs have occurred more frequently coincident with increased prescribing for SSTI. Increased usage alone may explain the increasing trend of TMP-SMX ADRs in children; however drug-disease interaction may play a role and requires further investigation.

Antibiotic therapy for inducible AmpC β-lactamase-producing Gram-negative bacilli: what are the alternatives to carbapenems, quinolones and aminoglycosides?

Some bacteria that possess chromosomally determined AmpC β-lactamases may express these enzymes at a high level following exposure to β-lactams, either by induction or selection for derepressed mutants. This may lead to clinical failure even if an isolate initially tests susceptible in vitro, a phenomenon best characterised by third-generation cephalosporin therapy for Enterobacter bacteraemia or meningitis. Several other Enterobacteriaceae, such as Serratia marcescens, Citrobacter freundii, Providencia spp. and Morganella morganii (often termed the 'ESCPM' group), may also express high levels of AmpC. However, the risk of clinical failure with β-lactams that test susceptible in vitro is less clear in these species than for Enterobacter. Laboratories frequently do not report β-lactam or β-lactamase inhibitor combination drug susceptibilities for ESCPM organisms, encouraging alternative therapy with quinolones, aminoglycosides or carbapenems. However, quinolones and carbapenems present problems with selective pressure for multiresistant organisms, and aminoglycosides with potential toxicity. The risk of emergent AmpC-mediated resistance for non-Enterobacter spp. appears rare in clinical studies. Piperacillin/tazobactam may remain effective and may be less selective for AmpC derepressed mutants than cephalosporins. The potential roles for agents such as cefepime or trimethoprim/sulfamethoxazole are also discussed. Clinical studies that better define optimal treatment for this group of bacteria are required.

Quality of life in children with vesicoureteral reflux

Vesicoureteral reflux (VUR) is commonly diagnosed in children presenting with urinary tract infections. Antibiotic prophylaxis and ureteric surgery are standard treatments for these children. Our aim was to investigate whether health-related quality of life (HRQOL) was altered in children treated for VUR. Children aged 1-5 years with grade III or higher VUR were identified through electronic records at the Stollery Children's Hospital. Parents of these children were mailed the TNO-AZL Netherlands Organisation for Applied Scientific Research Academic Medical Centre Quality of Life (TAPQOL) questionnaire. QOL scores for this group were compared with normative controls from the instrument's creators using the Mann-Whitney U test. Thirty-two of the 96 (33%) mailed surveys were returned. Eight children had surgery, and 19 were treated with antibiotic prophylaxis. When comparing the VUR group with the control group, we found that anxiety and social functioning scores were significantly better in patients with VUR (p < 0.01). The VUR group had worse scores in problem behavior, stomach complaints ,and communication (p < 0.01). This study reveals that children with VUR have a reasonable QOL when compared with controls. However, the diagnosis of VUR and its management does have an impact on gastrointestinal complaints, behavior, and communication, which may occur as a result of chronic medical intervention.

Neurotoxic effects associated with antibiotic use: management considerations

The clinical manifestations of antibiotic-induced neurotoxic effects, the underlying mechanisms and management strategies have been reviewed. PubMed and OVID searches (January 1960-June 2010) were conducted using search terms such as antibiotics, side effects, neurotoxicity and encephalopathy which yielded approximately 300 articles. All relevant case reports, case series, letters and retrospective reviews describing neurotoxic effects and those discussing mechanisms of neurotoxicity were included. Antibiotic-induced neurotoxic side effects can have a myriad of neurologic presentations. Patients with prior central nervous system (CNS) disease, renal insufficiency and advanced age may be particularly vulnerable. Treatment consists of discontinuation of the offending agent, use of antiepileptic drugs in the case of seizures or status epilepticus and haemodialysis in certain cases. The risk of CNS toxicity may be reduced via dosage adjustments in high risk populations. Awareness of the potential neurotoxic clinical manifestations of various antibiotics and high degree of vigilance in critically ill patients is essential in identifying a potentially serious, though reversible complications of antibiotic therapy particularly with the advent of newer antimicrobial agents.

Changes in bacterial resistance patterns in children with urinary tract infections on antimicrobial prophylaxis at University Hospital in Split

BACKGROUND

We assessed prevalence and resistance of uropathogens on antimicrobial agents (AA) from urine cultures (UC) in children hospitalized with urinary tract infections (UTI) at University Hospital in Split.

MATERIAL/METHODS

During the 7-year period, children hospitalized only once with UTI alone were compared to those repeatedly hospitalized, and who received long-term antimicrobial prophylaxis (LTAP), as well as those with associated anomalies of the urinary system (US).

RESULTS

E. coli was the most frequent isolate (67.7%) with resistance to ampicillin by 69.5%, amoxicillin/clavulonic acid by 3.5%, cephalexin by 6.6%, trimethoprim/sulfamethoxazole (TMP-SMX) by 27.5%, and nitrofurantoin by 0.4%. For other uropathogens, AA resistance rates were the following: 64.3%, 5.8%, 10.5%, 21.3%, and 7.9%. The high or increasing resistance to TMP-SMX is characterized by all uropathogens. Patients with anomalies of US showed a lower prevalence of E. coli and Enterococcus sp., but a higher prevalence of Pseudomonas sp., ESBL-producing E. coli and Klebsiella sp. than those without US anomalies. Repeatedly hospitalized patients showed a lower prevalence of E. coli, but a higher prevalence of Pseudomonas sp. and Klebsiella sp. than patients hospitalized only once. Both groups displayed significantly less resistance of Enterococcus sp. In patients receiving LTAP before hospitalization, E. coli was significantly more resistant to ampicillin, amoxicillin/clavulonic acid and TMP/SMX than in those without LTAP.

CONCLUSIONS

Based on our results, we recommend excluding ampicillin altogether, and reconsideration of further use of TMP-SMX, as well as use of nitrofurantoin, cephalexin and amoxicillin/clavulonic acid for LTAP in our region.

Childhood linear IgA bullous disease induced by trimethoprim-sulfamethoxazole

BACKGROUND

Linear IgA bullous disease (LABD) is a rare mucocutaneous autoimmune subepidermal blistering disease that can affect children mostly of pre-school age. As many as two-thirds of LABD are related to drug ingestion, particularly certain antibiotics, non-steroidal anti-inflammatory drugs and diuretics.

MAIN OBSERVATION

We describe a 3-year-old boy who presented a CMV infection followed by LABD induced by trimtheporim-sulfametoxazole. To our knowledge, this is the first reported case of trimethoprim-sulfamethoxazole that was confirmed by a rechallenge.

CONCLUSIONS

Most cases of drug-induced LABD are patients being treated with multiple systemic drugs that could induce the LABD. In the lack of suitable alternative treatment, the identification of the causative drug can be achieved by a rechallenge under close medical surveillance.

Costs and consequences of universal sibling screening for vesicoureteral reflux: decision analysis

OBJECTIVE

Our objective was to evaluate screening for vesicoureteral reflux (VUR) among siblings of patients with VUR, in terms of cost, radiation exposure, and number of febrile urinary tract infections (fUTIs) averted.

METHODS

We constructed a Markov model to evaluate 2 competing management options, that is, universal screening (cystographic evaluation of all siblings without symptoms) and usual care (cystographic evaluation of siblings only after fUTIs). Published data were used to inform all model inputs. Costs were estimated by using a societal perspective.

RESULTS

Universal screening yielded 2980 fUTIs, whereas usual care yielded 6330. Therefore, universal screening for VUR in a cohort of 100,000 siblings 1 year of age without symptoms resulted in the prevention of 1 initial fUTI per 3360 siblings, at an excess cost of $55,600 per averted fUTI, in comparison with usual care. These estimates were heavily dependent on screening age and the effectiveness of antibiotic prophylaxis; prevention of a single fUTI would require screening of 166 siblings 5 years of age and 694 siblings 10 years of age. Similarly, if prophylaxis was ineffective in preventing fUTIs, then up to 10,000 siblings would need to be screened for prevention of a single fUTI.

CONCLUSIONS

Prevention of a single fUTI would require screening of 30 to 430 siblings 1 year of age without symptoms, at an estimated excess cost of $56,000 to $820,000 per averted fUTI. These estimates are heavily dependent on screening age and the effectiveness of antibiotic prophylaxis.

Is antibiotic prophylaxis effective in preventing urinary tract infections in patients with vesicoureteral reflux?

The main concern in the management of children with vesicoureteral reflux (VUR) is the prevention of urinary tract infections and avoidance of renal damage. Medical management has been recommended or preferentially suggested over surgery in all but a few select clinical situations. Prophylactic antibiotics are prescribed routinely in the management of young children with radiological evidence of VUR following an episode of acute pyelonephritis. Prophylaxis is generally maintained until the VUR resolves spontaneously or is corrected surgically. Although the administration of prophylactic antibiotics has been universal in children with VUR, some authors have reported that long-term antibiotic prophylaxis does not fully prevent urinary tract infections or scarring, that antibiotic-related adverse events are known to occur, and that the incidence of pyelonephritis does not increase in spite of prophylactic antibiotic cessation. Recently, four prospective, randomized, controlled trials of antibiotic prophylaxis for preventing pyelonephritis and renal scarring were reported and some placebo-controlled, double-blind prospective studies are ongoing. The goal of this review is to evaluate the treatment of VUR using antibiotic prophylaxis, and its advantages and disadvantages based on appropriate descriptions and studies in the literature.

Are prophylactic antibiotics indicated after a urinary tract infection?

PURPOSE OF REVIEW

Many children with urinary tract infection (UTI) and urinary tract abnormality such as vesicoureteral reflux (VUR) are given prophylactic antibiotic to prevent recurrence of UTI and permanent kidney damage. Occasionally, children with normal urinary tract receive prophylactic antibiotic to alleviate the patient suffering and family inconvenience associated with recurrent symptomatic UTI. These recommendations are mostly opinion-based and are derived from studies that were not randomized and were done before the current renal imaging modalities became available. The purpose of this review is to discuss these recommendations in the context of recent research findings.

RECENT FINDINGS

Recent studies have raised serious doubts about the role of antibiotic prophylaxis after UTI by demonstrating the presence of preexisting renal scars without UTI in some patients, systematic reviews of published literature on UTI and VUR, and by comparing randomized patients with VUR who received antibiotic prophylaxis with those who did not receive any prophylaxis. However, the new knowledge has also highlighted that,apart from skillful management of individual patients, well designed studies are needed to answer the questions on antibiotic prophylaxis across the spectrum of UTI in different clinical situations. One such study currently underway is the Randomized Intervention for Children With Vesicoureteral Reflux (RIVUR) study, which will evaluate the role of antibiotic prophylaxis in preventing recurrent UTI and renal scarring in young children with VUR.

SUMMARY

It is advisable that, until the results of more appropriately designed studies become available, UTI in young children is considered as a risk factor for renal scarring and each patient is treated with prudence.

Association of the diplotype configuration at the N-acetyltransferase 2 gene with adverse events with co-trimoxazole in Japanese patients with systemic lupus erythematosus

Although co-trimoxazole (trimethoprim-sulphamethoxazole) is an effective drug for prophylaxis against and treatment of Pneumocystis pneumonia, patients often experience adverse events with this combination, even at prophylactic doses. With the aim being to achieve individual optimization of co-trimoxazole therapy in patients with systemic lupus erythematosus (SLE), we investigated genetic polymorphisms in the NAT2 gene (which encodes the metabolizing enzyme of sulphamethoxazole). Of 166 patients with SLE, 54 patients who were hospitalized and who received prophylactic doses of co-trimoxazole were included in the cohort study. Adverse events occurred in 18 patients; only two experienced severe adverse events that lead to discontinuation of the drug. These two patients and three additional ones with severe adverse events (from other institutions) were added to form a cohort sample and were analyzed in a case-control study. Genotype was determined using TaqMan methods, and haplotype was inferred using the maximum-likelihood method. In the cohort study, adverse events occurred more frequently in those without the NAT2*4 haplotype (5/7 [71.4%]) than in those with at least one NAT2*4 haplotype (13/47 [27.7%]; P = 0.034; relative risk = 2.58, 95% confidence interval = 1.34-4.99). In the case-control study the proportion of patients without NAT2*4 was significantly higher among those with severe adverse events (3/5 [60%]) than those without severe adverse events (6/52 [11.5%]; P = 0.024; odds ratio = 11.5, 95% confidence interval = 1.59-73.39). We conclude that lack of NAT2*4 haplotype is associated with adverse events with co-trimoxazole in Japanese patients with SLE.

Probable Labetalol-Induced Hepatotoxicity

This article reports a case of probable hepatotoxicity induced by therapeutic doses of labetalol. A 34-year-old postpartum woman was started on labetalol during a preeclamptic episode in the hospital. During the patient's 4-week postpartum office visit, she reported having dark urine for the previous 2 weeks. A liver function test showed substantial enzyme elevation, which improved after discontinuation of labetalol therapy. Labetalol-induced hepatotoxicity, although uncommon, can occur. Published data report this occurrence only in middle-aged or older patients. This appears to be the first case report of postpartum labetalol-induced hepatotoxicity. Hepatotoxicity may occur as a result of labetalol therapy. More judicious monitoring in patients on labetalol therapy may be warranted to prevent serious outcomes.

Is antibiotic prophylaxis necessary in infants with obstructive hydronephrosis?

PURPOSE

We investigated the relationship between the level of obstruction of the upper urinary tract and the risk and onset of urinary tract infection in infants with severe obstructive hydronephrosis to determine the need for antibiotic prophylaxis.

MATERIALS AND METHODS

A total of 105 patients were prenatally diagnosed with severe hydronephrosis (Society for Fetal Urology grade III or IV) due to upper urinary tract obstruction between 1994 and 2004. Of these patients 75 had ureteropelvic junction obstruction and 30 had lower ureteral obstruction. We retrospectively evaluated the clinical course and incidence of urinary tract infection during the first 12 months postnatally without antibiotic prophylaxis.

RESULTS

The incidence of overall urinary tract infection during followup was 36.2% (38 of 105 patients), and it demonstrated a higher trend with lower ureteral obstruction than with ureteropelvic junction obstruction (50% vs 30.7%, p=0.063). Most cases of urinary tract infection (92.8%) occurred before age 6 months, with a mean age at onset of 2.6 months. Of 105 patients 77 (73.3%) underwent corrective surgery at a mean age of 3.8 months. The incidence of urinary tract infection before surgical correction was 33.8% at a mean age of 2.1 months. The incidence of urinary tract infection in surgical cases was significantly higher with lower ureteral obstruction than with ureteropelvic junction obstruction (54.2% vs 24.5%, p=0.011).

CONCLUSIONS

Urinary tract infection in infants with severe obstructive hydronephrosis has a high incidence, occurs before age 6 months and is more common with lower ureteral obstruction than with ureteropelvic junction obstruction. These findings indicate that infants with severe hydronephrosis due to obstruction of the upper urinary tract should receive antibiotic prophylaxis.

Medical management of vesicoureteral reflux--quiz within the article. Don't overlook placebos

Vesicoureteral reflux (VUR) in children is associated with increased risk of urinary tract infection (UTI). Recurrent UTI in the presence of the VUR is believed to cause renal scarring, which carries a risk of subsequent hypertension, toxemia of pregnancy, and significant renal damage, including end-stage renal disease. The natural history of VUR is to improve or resolve completely with time in most of the patients. The traditional management consists of prompt treatment of UTI, long-term anti-microbial prophylaxis until the VUR resolves, or surgical intervention in those with persistent high grade VUR, recurrent UTI in spite of prophylaxis with anti-microbial agent, allergy to anti-microbial agents, and patient/parent non-compliance with the medical management. Voiding dysfunction and constipation play an important role, and their diagnosis and appropriate management helps reduce the frequency of UTI and promote the resolution of the VUR. Patients with renal scarring need to be monitored for potential complications such as hypertension, proteinuria, and progression of the renal damage. In patients with hypertension and/or proteinuria, angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) are the drugs of choice, because of their reno-protective properties. Recent studies have revealed that there is no convincing evidence that UTI in the presence of VUR predicts renal injury or that the use of long-term anti-microbial prophylaxis or surgical intervention prevents renal scarring or its progression. However, until proven otherwise by a prospective, placebo-controlled, randomized study, it is advisable to err on the side of caution and consider VUR and UTI risk factors for renal scarring and treat each patient on individual basis.

Antibiotic resistance of urinary tract pathogens and evaluation of empirical treatment in Turkish children with urinary tract infections

The changing pattern of antimicrobial resistance in the causative microorganisms of urinary tract infection (UTI) in childhood is a growing problem. The aims of this study were to assess the resistance patterns of urinary isolates to commonly used antimicrobials and to evaluate the options for empirical treatment of UTI. A prospective cross-sectional analysis of bacteria isolated from children with UTI was performed between January 2003 and January 2004. Resistance to antibiotics was analysed in three age groups: Group I, < or =12 months; Group II, 13-60 months; and Group III, >60 months. A total of 165 urinary pathogens were isolated from 131 patients. Mean patient age was 63.7+/-49.8 months. The most common causative agent was Escherichia coli (87% of cases) followed by Klebsiella pneumoniae (10%). Resistance to ampicillin (74.2%) and co-trimoxazole (61.3%) was significant in all isolates. Nitrofurantoin was the most active agent against E. coli (2.2% resistant isolates), followed by amikacin (4.9%), ceftriaxone (7.5%) and ciprofloxacin (12%). None of the isolates from Group I patients were resistant to ciprofloxacin and a low resistance rate (7.1%) was noted for amikacin. In Group II patients, none of the isolates were resistant to amikacin, and ceftriaxone was the second most suitable antibiotic (resistance rate 2.2%). In Group III patients, the lowest resistance rate was against nitrofurantoin (2.7%). In conclusion, we observed that the use of ampicillin and co-trimoxazole as a single agent for empirical treatment of a suspected UTI would not cover the majority of urinary pathogens in our region. Whilst amikacin, with a negligible resistance rate, was suitable in all age groups, gentamicin might still be useful as an empirical treatment of UTI in children aged >1 year. Nitrofurantoin could be included as a reasonable alternative in the empirical treatment of lower UTI in older children.

Aetiological factors related to a positive direct antiglobulin test result in human immunodeficiency virus-infected patients

BACKGROUND AND OBJECTIVES

The aim of this study was to examine the clinical importance and causes of a positive result in the direct antiglobulin test (DAT) in human immunodeficiency virus-infected (HIV(+)) patients. We therefore studied haematological parameters in outpatient samples, and also analysed the impact of highly active anti-retroviral therapy (HAART) on the DAT results.

STUDY DESIGN AND METHODS

Haematological parameters, clinical stages, chemo-antibiotic treatments and HAART treatment were studied to determine any relationships with DAT results in 115 consecutive HIV(+) patients.

RESULTS

Significantly lower haemoglobin (Hb) levels were detected in patients with HIV who had a positive DAT result. Hepatitis C virus (HCV) co-infection (odds ratio 2.529) and trimethoprim-suphamethoxazfole (TMP-SMX) prophylaxis (odds ratio 3.751) had a significant association with DAT positivity. Patients receiving HAART were less likely to have a positive DAT [odds ratio (OR) 0.383; P = 0.035]. Among the patients treated with TMP-SMX, those with a positive DAT had lower Hb levels (11.9 g/dl) than those with a negative DAT (14.2 g/dl; P = 0.04). HCV antibody positivity and TMP-SMX prophylaxis showed a cumulative effect on positive DATs (OR 4.533). The surface exploratory analysis indicated the distribution of the positive DATs in relationship with the CD4(+) count and Hb levels.

CONCLUSIONS

Significantly lower Hb levels were detected in DAT-positive HIV(+) patients. HCV co-infection and TMP-SMX prophylaxis appear to confer an increased risk of DAT positivity. The presence of red blood cell autoantibodies may be associated with anaemia in HIV disease in the absence of overt haemolysis.