Linezolid-associated peripheral and optic neuropathy in children

Clinical Practice Guideline by the Pediatric Infectious Diseases Society (PIDS) and the Infectious Diseases Society of America (IDSA): 2023 Guideline on Diagnosis and Management of Acute Bacterial Arthritis in Pediatrics

This clinical practice guideline for the diagnosis and treatment of acute bacterial arthritis (ABA) in children was developed by a multidisciplinary panel representing the Pediatric Infectious Diseases Society (PIDS) and the Infectious Diseases Society of America (IDSA). This guideline is intended for use by healthcare professionals who care for children with ABA, including specialists in pediatric infectious diseases and orthopedics. The panel's recommendations for the diagnosis and treatment of ABA are based upon evidence derived from topic-specific systematic literature reviews. Summarized below are the recommendations for the diagnosis and treatment of ABA in children. The panel followed a systematic process used in the development of other IDSA and PIDS clinical practice guidelines, which included a standardized methodology for rating the certainty of the evidence and strength of recommendation using the GRADE approach (Grading of Recommendations Assessment, Development and Evaluation) (see Figure 1). A detailed description of background, methods, evidence summary and rationale that support each recommendation, and knowledge gaps can be found online in the full text.

Linezolid toxic optic neuropathy: A case report and review of visual prognosis

Purpose

To describe a case of linezolid toxic optic neuropathy in a 71-year-old female and review the relevant literature.

Observations

An adult female with progressive, symmetric vision loss was hypothesized to have linezolid toxic optic neuropathy. Following cessation of linezolid, the patient experienced improvement in visual function over two months.

Conclusions and importance

Patients diagnosed with linezolid toxic optic neuropathy can expect some return of visual function after cessation. The degree of return does not correlate to the cumulative dose of the drug. The goal of this study was to summarize and add to the current body of literature on the topic.

Role of Daptomycin in Cutaneous Wound Healing: A Narrative Review

Daptomycin is active against Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and the on-label indications for its use include complicated skin and skin structure infections (cSSSI). We performed a narrative review of the literature with the aim to evaluate the role of daptomycin in the skin wound healing process, proposing our point of view on the possible association with other molecules that could improve the skin healing process. Daptomycin may improve wound healing in MRSA-infected burns, surgical wounds, and diabetic feet, but further studies in humans with histological examination are needed. In the future, the combination of daptomycin with other molecules with synergistic action, such as vitamin E and derivates, IB-367, RNA III-inhibiting peptide (RIP), and palladium nanoflowers, may help to improve wound healing and overcome forms of antibiotic resistance.

Clinical Practice Guideline by the Pediatric Infectious Diseases Society and the Infectious Diseases Society of America: 2021 Guideline on Diagnosis and Management of Acute Hematogenous Osteomyelitis in Pediatrics

This clinical practice guideline for the diagnosis and treatment of acute hematogenous osteomyelitis (AHO) in children was developed by a multidisciplinary panel representing Pediatric Infectious Diseases Society (PIDS) and the Infectious Diseases Society of America (IDSA). This guideline is intended for use by healthcare professionals who care for children with AHO, including specialists in pediatric infectious diseases, orthopedics, emergency care physicians, hospitalists, and any clinicians and healthcare providers caring for these patients. The panel's recommendations for the diagnosis and treatment of AHO are based upon evidence derived from topic-specific systematic literature reviews. Summarized below are the recommendations for the diagnosis and treatment of AHO in children. The panel followed a systematic process used in the development of other IDSA and PIDS clinical practice guidelines, which included a standardized methodology for rating the certainty of the evidence and strength of recommendation using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. A detailed description of background, methods, evidence summary and rationale that support each recommendation, and knowledge gaps can be found online in the full text.

Host bioenergetic parameters reveal cytotoxicity of anti-tuberculosis drugs undetected using conventional viability assays

High attrition rates in tuberculosis (TB) drug development have been largely attributed to safety, which is likely due to the use of endpoint assays measuring cell viability to detect drug cytotoxicity. In drug development for cancer, metabolic, and neurological disorders and for antibiotics, cytotoxicity is increasingly being assessed using extracellular flux (XF) analysis, which measures cellular bioenergetic metabolism in real time. Here, we adopt the XF platform to investigate the cytotoxicity of drugs currently used in TB treatment on the bioenergetic metabolism of HepG2 cells, THP-1 macrophages, and human monocyte-derived macrophages (hMDMs). We found that the XF analysis reveals earlier drug-induced effects on the cells’ bioenergetic metabolism prior to cell death, measured by conventional viability assays. Furthermore, each cell type has a distinct response to drug treatment, suggesting that more than one cell type should be considered to examine cytotoxicity in TB drug development. Interestingly, chemically unrelated drugs with different modes of action on Mycobacterium tuberculosis have similar effects on the bioenergetic parameters of the cells, thus discouraging the prediction of potential cytotoxicity based on chemical structure and mode of action of new chemical entities. The clustering of the drug-induced effects on the hMDM bioenergetic parameters are reflected in the clustering of the effects of the drugs on cytokine production in hMDMs, demonstrating concurrence between the effects of the drugs on the metabolism and functioning of the macrophages. These findings can be used as a benchmark to establish XF analysis as a new tool to assay cytotoxicity in TB drug development.

Intravitreal linezolid in the management of vancomycin-resistant enterococcal endophthalmitis

Purpose

Linezolid is a synthetic antibiotic, the first of the oxazolidinone class, used for the treatment of infections caused by multi-resistant bacteria including Streptococcus, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). We report on a case of endophthalmitis caused by vancomycin-resistant Enterococcus feacium treated with intravitreal linezolid. It has proved efficacious in animal models but its safety in humans is not fully known.

Observations

An 84-year-old man who had phacoemulsification surgery and anterior chamber intraocular lens due to posterior capsule rent. Visual acuity (VA) following surgery was 6/24 uncorrected. The following week he developed signs of endophthalmitis, characterized by corneal infiltration and keratic precipitates, with anterior chamber and vitreous haze. Cultures yielded no growth, while repeated treatments with intravitreal vancomycin, ceftazidime, and amphotericin B did not control the infection. Vitrectomy was performed twice during the patient's course, with intravitreal amikacin injection after the second vitrectomy, but poor control of the endophthalmitis persisted. After several weeks of limited response to treatments, the diagnosis was finally made using Giemsa stain of direct smear which showed characteristic morphology of Enterococcus faecium. Linezolid, one of the oxazo-lidinones, was initially given in oral form 600 mg BID for three weeks, but did not prove efficacious. Subsequently, intravitreal linezolid 200 mcg in 0.1ml was injected, which cleared the vitreous and cornea infection within a week. However, there was a residual exudative detachment of the retina in the posterior pole, leaving the patient with a final vision of hand movement.

Conclusion and importance

Vancomycin-resistant enterococcus is a rare cause of endophthalmitis. Intravitreal linezolid is an effective treatment, but the subsequent exudative retinal detachment may have been related to this novel therapy.

Increasing use of linezolid in a tertiary NICU during a 10-year period: reasons and concerns for the future

Background

Linezolid has been increasingly used in tertiary NICUs. The objectives of this study were to explore the indications of these linezolid prescriptions, to analyze a possible misuse and to provide solutions to avoid such misuse.

Methods

A monocentric retrospective cohort study included all neonates hospitalized in one tertiary NICU between January 1st, 2010 and December 31st, 2019 and who received at least one administration of linezolid. These data were confronted to epidemiological and antibiotic use data from the same NICU. Two independent pediatricians secondarily classified linezolid uses as adequate or not.

Results

During the study period, 66 infections in 57 patients led to linezolid use. Most patients were pre-term and 21 patients (37%) died. Infections were mainly related to methicillin-resistant coagulase negative staphylococci and were frequently either pneumoniae (35%) or isolated bacteremia (48%), including 25 persistent bacteremia (64% of the 39 bacteremia). Need for a better tissue distribution or first-line treatment failure were the main reasons to initiate linezolid. Linezolid was administered for a median duration of 7 [3;10] days. No side effects were reported. Twenty-two (33%) of the 66 linezolid prescriptions were retrospectively classified as inadequate.

Conclusions

A rapid increase in linezolid prescriptions has been observed in our tertiary NICU, from 2014 to 2019, with 33% inadequate uses. This worrisome trend should lead to search for therapeutic alternatives and to work on antibiotic stewardship to prevent the emergence of new antimicrobial bacterial resistance.

Comparative Effectiveness of Vancomycin Versus Linezolid for the Treatment of Acute Pulmonary Exacerbations of Cystic Fibrosis

Background: Data are limited regarding the preferred antibiotics for treatment of acute pulmonary exacerbations (APEs) of cystic fibrosis (CF), when methicillin-resistant Staphylococcus aureus (MRSA) is suspected. Objective: To compare the rate of return to baseline lung function among individuals with APEs of CF treated with either vancomycin or linezolid. Methods: This retrospective study included individuals hospitalized for APEs of CF from May 1, 2015, to April 30, 2017 who were infected with MRSA and treated with vancomycin or linezolid. The primary outcome was the return to baseline lung function, as measured by forced expiratory volume in 1 s (FEV1). Descriptive and inferential statistics were used. All tests were 2-tailed with α set at 0.05. Results: A total of 122 encounters were included (vancomycin: n = 66; linezolid: n = 66). No difference existed in return to baseline FEV1 between vancomycin (53 [80.3%]) and linezolid (50 [75.8%]; P = 0.53); nor was there a difference in median percentage change in FEV1 from admission to follow-up between vancomycin (24.7%) and linezolid (20.7%; P = 0.61). Adverse drug events occurred more frequently in patient encounters treated with vancomycin (10 [15.2%]) compared with linezolid (2 [3%]; P = 0.002). Conclusion and Relevance: Our study observed no difference in the effectiveness of vancomycin compared with linezolid in terms of change in lung function for APEs of CF. The rate of adverse drug events was low. In individuals with CF infected with MRSA who are experiencing an APE, either vancomycin or linezolid appear to be viable treatment options.

Linezolid-containing Treatment Regimens for Tuberculosis in Children

BACKGROUND

In recent years, there is an increasing interest in the use of linezolid for the treatment of tuberculosis (TB).

METHODS

Patients less than 18 years of age who received linezolid within the Spanish Pediatric TB Network from 2001 to 2016 were retrospectively included. Treatment characteristics, adverse events (AEs) and outcomes were analyzed.

RESULTS

Fifteen children were included (53% male) with a median age of 3.6 years [interquartile range (IQR): 1.6-6.2]. Median follow-up was 54 months (IQR: 38-76). The reasons for linezolid use were drug-resistant TB in 8 (53%) patients, drug-induced liver injury in 5 (33%) patients and chronic liver disease in 2 (13%) patients. Four children (26%) were on immunosuppressive therapy when TB was diagnosed. Five children (33%) were diagnosed with extrapulmonary TB. The median duration of linezolid treatment was 13 months (IQR: 7.5-17). Nine patients had 13 linezolid-related AEs. Hematologic toxicity was observed in 8 patients (53%) and gastrointestinal intolerance in 3 patients (20%). In 2 patients, linezolid dose was reduced, and in 2 patients, linezolid was discontinued because of AEs. A 2-year-old girl went back to her country of birth and was lost to follow-up. No relapses were observed among the other 14 patients (93%).

CONCLUSIONS

Linezolid may be considered when treating children with drug-resistant TB but also in the cases of patients with chronic liver disease or drug-induced liver injury. However, AEs should be closely monitored. Further studies are needed to determine the optimum dosage and the optimal duration of linezolid treatment in children.

Management of Pediatric Acute Hematogenous Osteomyelitis, Part II: A Focus on Methicillin-Resistant Staphylococcus aureus, Current and Emerging Therapies

Methicillin-resistant Staphylococcus aureus (MRSA) has become the most prevalent cause of acute hematogenous osteomyelitis (AHO) in pediatric patients. This increase in MRSA is due to the rise in community-acquired MRSA. Therefore, it is important that clinicians are aware of the various and upcoming therapies that cover this bacterium. A literature search of the Medline database was performed from creation through January 2018. Articles chosen for the review emphasize well-established MRSA treatment options for pediatric AHO, newer therapies on the horizon, and important pharmacokinetics and pharmacodynamic concepts for treatment. Traditional therapies, including vancomycin and clindamycin, remain effective for the treatment of pediatric AHO. When these agents cannot be used, evidence in AHO has been growing for daptomycin, linezolid, and ceftaroline. Further initial pediatric data with the long-acting lipoglycopeptides show promise and in the future may provide a role in AHO treatment in children.

Peripheral neuropathy in a diabetic child treated with linezolid for multidrug-resistant tuberculosis: a case report and review of the literature

Background

Extensively drug-resistant (XDR) tuberculosis (TB) and multidrug resistant (MDR)-TB with additional resistance to injectable agents or fluoroquinolones are challenging to treat due to lack of available, effective drugs. Linezolid is one of the few drugs that has shown promise in treating these conditions. Long-term linezolid use is associated with toxicities such as peripheral and optic neuropathies. Diabetes mellitus (DM), especially when uncontrolled, can also result in peripheral neuropathy. The global burden of DM is increasing, and DM has been associated with a three-fold increased risk of developing TB disease. TB and DM can be a challenging combination to treat. DM can inhibit the host immune response to tuberculosis infection; and TB and some anti-TB drugs can worsen glycaemic control. A child experiencing neuropathy that is a possible complication of both DM and linezolid used to treat TB has not been reported previously. We report peripheral neuropathy in a 15-year-old boy with type 1 DM, diagnosed with MDR-TB and additional resistance to injectable TB medications.

Case presentation

The boy was treated with a linezolid-based regimen, but after 8 months developed peripheral neuropathy. It was unclear whether the neuropathy was caused by the DM or the linezolid therapy. He had clinical improvement following cessation of linezolid and was declared cured following 21 months of treatment. Following completion of treatment, nerve conduction studies demonstrated significant improvement in neuropathy.

Conclusions

To the best of our knowledge, this is the first case of peripheral neuropathy reported in a diabetic child on long-term linezolid therapy for tuberculosis. This case study underlines the importance of stringent follow-up for side effects of linezolid, especially when associated with co-morbidity such as DM that increases the chances of adverse effects. The presence of both DM and TB should alert a physician to strive for optimal glycaemic control to minimize the risk of complications as well as optimizing the chances of recovery from TB. Our case report shows the need for close and frequent monitoring for neuropathy to enable early intervention and thereby a favourable outcome in children who may otherwise suffer a long-lasting, debilitating, and painful neuropathy.

Complications associated with antibiotic administration: neurological adverse events and interference with antiepileptic drugs

Antibiotic use is associated with toxic effects involving the peripheral and central nervous systems and it may interfere with antiepileptic drugs, causing significant variations in their serum levels and activity. Prompt identification of neurological complications during antibiotic therapy is important in order to make appropriate modifications to medication. Characteristics of the drug and the patient, including age and underlying diseases, may favour these complications. The main aim of this study was to review the neurological adverse events that may follow antibiotic administration, the mechanisms that cause them, and the possibility of prevention and treatment. Moreover, the interference of antibiotics with serum levels and the activity of antiepileptic drugs are discussed. The results demonstrate that antibiotic-associated adverse events involving the nervous system are relatively uncommon and are only rarely severe and irreversible, although neurotoxicity has been reported for several antibiotics. Moreover, for patients receiving antiepileptic drugs, monitoring of drug serum levels to avoid the risk of toxicity or inadequate therapy is mandatory during antibiotic treatment. Areas for future research include the effects of combined antibiotic therapies as well as multiple antiepileptic drugs in study populations with an adequate sample size, including neonates and infants, patients with pharmacoresistant epilepsy and elderly patients.

Daptomycin for Complicated Skin Infections: A Randomized Trial

BACKGROUND

Complicated skin and skin structure infections (cSSSI) are common in children. Due to safety and resistance issues with recommended agents, new treatment options would be advantageous.

METHODS

Multicenter, evaluator-blinded clinical trial. Patients 1 to 17 years old with cSSSI caused by Gram-positive pathogens were randomized 2:1 to intravenous daptomycin or standard-of-care (SOC) treatment for ≤14 days. Daptomycin was administered once daily with dosing by patient age: 12 to 17 years, 5 mg/kg; 7 to 11 years, 7 mg/kg; 2 to 6 years, 9 mg/kg; 12 to 23 months, 10 mg/kg. The primary objective was to evaluate daptomycin safety. The secondary objective was to assess the efficacy of daptomycin compared with SOC. The intent-to-treat (ITT) population consisted of all randomized patients with any dose of study drug.

RESULTS

The ITT population comprised 257 daptomycin and 132 SOC patients (primarily clindamycin or vancomycin); 35% had confirmed methicillin-resistant Staphylococcus aureus. The most common adverse events were diarrhea (7% daptomycin, 5% SOC) and increased creatine phosphokinase (6% daptomycin, 5% SOC). The proportions of safety population patients with treatment-related adverse events were similar between the daptomycin (14%) and SOC (17%) groups. Clinical success rates (blinded evaluator-assessed complete/partial resolution of cSSSI signs and symptoms 7-14 days after end-of-treatment) in the ITT population were also similar for the daptomycin (91%) and SOC groups.

CONCLUSIONS

Once-daily daptomycin was well tolerated, with safety and efficacy comparable to SOC in children/adolescents with cSSSI caused by Gram-positive pathogens, including community-acquired methicillin-resistant S aureus.

Safety of long-term use of linezolid: results of an open-label study

Objective

The objective of this study was to assess the long-term safety of linezolid in patients with chronic infections requiring treatment for ≥6 weeks. Enhanced monitoring for optic neuropathy was included to characterize the early development of this side effect and to identify ophthalmologic tests that might be valuable in early detection of this event.

Methods

This was a multicenter, open-label, pilot study of patients aged ≥18 years on long-term linezolid therapy. Matched control patients were included for baseline assessment comparison. Patients were assessed at study entry, monthly while on treatment, at the end of treatment, and 30 days following the last dose. Aggregate ocular safety data were reviewed. Response to treatment was reported.

Results

The study was terminated owing to slow enrollment. Twenty-four patients received linezolid; nine patients were included as matched controls. Linezolid was prescribed for a median of 80.5 days (range, 50–254 days). In patients with a reported clinical outcome, the majority were considered improved or cured. Common treatment-related adverse events (AEs) included anemia, peripheral neuropathy, polyneuropathy, vomiting, and asthenia, and were consistent with the known safety profile. Most AEs resolved or stabilized with discontinuation of treatment. Results of ophthalmologic tests in the one case adjudicated as probable linezolid-associated optic neuropathy revealed abnormal color vision, characteristic changes in the optic disk, and central scotomas in each eye.

Conclusion

In our small population, linezolid was generally well tolerated and AEs were consistent with the known safety profile. Extensive ophthalmologic testing of all 24 linezolid-treated patients identified one case adjudicated as probable, linezolid-associated optic neuropathy.

Adverse effects of oral second-line antituberculosis drugs in children

INTRODUCTION

Increasing numbers of children with drug-resistant tuberculosis are accessing second-line antituberculosis drugs; these are more toxic than first-line drugs. Little is known about the safety of new antituberculosis drugs in children. Knowledge of adverse effects, and how to assess and manage these, is important to ensure good adherence and treatment outcomes.

AREAS COVERED

A Pubmed search was performed to identify articles addressing adverse effects of second-line antituberculosis drugs; a general search was done for the new drugs delamanid and bedaquiline. This review discusses adverse effects associated with oral second-line antituberculosis drugs. The spectrum of adverse effects caused by antituberculosis drugs is wide; the majority are mild or moderate, but these are important to manage as it could lead to non-adherence to treatment. Adverse effects may be more common in HIV-infected than in HIV-uninfected children.

EXPERT OPINION

Although children may experience fewer adverse effects from oral second-line antituberculosis drugs than adults, evidence from prospective studies of the incidence of adverse events in children is limited. Higher doses of second-line drugs, new antituberculosis drugs, and new drug regimens are being evaluated in children: these call for strict pharmacovigilance in children treated in the near future, as adverse effect profiles may change.

Pharmacokinetics, Safety and Tolerability of Single Oral or Intravenous Administration of 200 mg Tedizolid Phosphate in Adolescents

BACKGROUND

Tedizolid is a novel oxazolidinone antibacterial US FDA approved for treatment of acute bacterial skin and skin structure infections in adults. This study assessed the pharmacokinetics, safety and tolerability of tedizolid phosphate in adolescents (12-17 years old) after administration of a single intravenous (IV) or oral dose.

METHODS

In this multicenter, open-label study, a single IV infusion (N = 10) or oral dose (N = 10) of 200 mg tedizolid phosphate was administered to adolescents already receiving antibacterial treatment for presumed or documented infection. Blood and urine samples were collected predose and over 24 hours.

RESULTS

Tedizolid pharmacokinetics was generally similar after IV or oral administration of 200 mg tedizolid phosphate. Mean (standard deviation) half-life values were similar for oral and IV routes, 8.3 (2.0) and 6.6 (0.7) hours, respectively. Absolute oral bioavailability of tedizolid (90% confidence interval) was 88.8% (70.4%-112.1%). Geometric mean ratio (90% confidence interval) of area under the concentration-time curve values for adolescents relative to values previously reported for adults after 200 mg of single-dose IV or oral administration were 0.847 (0.736-0.975). Tedizolid was well tolerated.

CONCLUSIONS

Overall pharmacokinetics of tedizolid was similar after administration of a single oral or IV 200 mg dose, and bioavailability was high. Exposure profiles were similar to those in adults. With clinical outcomes based on area under the concentration-time curve/minimum inhibitory concentration and current susceptibility of Gram-positive pathogens, results suggest that the 200 mg daily regimen of tedizolid phosphate can be extended to adolescents for clinical trials, and that dose adjustment may not be required when switching routes.

Safety and tolerability profile of second-line anti-tuberculosis medications

Tuberculosis (TB) remains a major public health problem, representing the second leading cause of death from infectious diseases globally, despite being nearly 100 % curable. Multidrug-resistant (MDR)-TB, a form of TB resistant to isoniazid and rifampicin (rifampin), two of the key first-line TB drugs, is becoming increasingly common. MDR-TB is treated with a combination of drugs that are less effective but more toxic than isoniazid and rifampicin. These drugs include fluoroquinolones, aminoglycosides, ethionamide, cycloserine, aminosalicyclic acid, linezolid and clofazimine among others. Minor adverse effects are quite common and they can be easily managed with symptomatic treatment. However, some adverse effects can be life-threatening, e.g. nephrotoxicity due to aminoglycosides, cardiotoxicity due to fluoroquinolones, gastrointestinal toxicity due to ethionamide or para-aminosalicylic acid, central nervous system toxicity due to cycloserine, etc. Baseline evaluation may help to identify patients who are at increased risk for adverse effects. Regular clinical and laboratory evaluation during treatment is very important to prevent adverse effects from becoming serious. Timely and intensive monitoring for, and management of adverse effects caused by, second-line drugs are essential components of drug-resistant TB control programmes; poor management of adverse effects increases the risk of non-adherence or irregular adherence to treatment, and may result in death or permanent morbidity. Treating physicians should have a thorough knowledge of the adverse effects associated with the use of second-line anti-TB drugs, and routinely monitor the occurrence of adverse drug reactions. In this review, we have compiled safety and tolerability information regarding second-line anti-TB drugs in both adults and children.

Optimizing therapy for vancomycin-resistant enterococcal bacteremia in children

PURPOSE OF REVIEW

Uncertainties exist regarding the optimal treatment for vancomycin-resistant enterococcal (VRE) bloodstream infections, particularly in settings in which ampicillin cannot be used.

RECENT FINDINGS

Quinupristin-dalfopristin, linezolid, and daptomycin, all approved between 1999 and 2003, represent the mainstays of therapy for VRE bacteremia, although only linezolid has been specifically approved by the United States Food and Drug Administration for this indication. The main objective of this review is to compare the relative efficacies, dosing strategies, and side-effect profiles of quinupristin-dalfopristin, linezolid, and daptomycin for VRE bacteremia in the pediatric population. A brief description of recently approved broad-spectrum Gram-positive agents that may have a role in the management of VRE bacteremia in upcoming years is also provided.

SUMMARY

Linezolid, despite its bacteriostatic activity against VRE, may be the most versatile of the available drugs. It has activity against both Enterococcus faecalis and E. faecium, can be administered orally, and resistance appears to be less of a concern with linezolid compared with the other agents. Additionally, the results of two recent meta-analyses demonstrate more favorable outcomes with linezolid compared with daptomycin for the treatment of VRE bacteremia. The clinical pharmacokinetics of linezolid have been well described in children. The most notable concern with linezolid, however, is toxicities associated with prolonged use. Until more prospective data are available, we favor linezolid as first-line therapy for the treatment of VRE bacteremia in children.

Antibiotic Management of Methicillin-Resistant Staphylococcus aureus–Associated Acute Pulmonary Exacerbations in Cystic Fibrosis

Objective: To review the treatment of methicillin-resistant Staphylococcus aureus (MRSA)–associated acute pulmonary exacerbations (APEs) in cystic fibrosis (CF). Data Sources: A search of PubMed, MEDLINE, Cochrane Library and Clinicaltrials.gov databases through November 2014 was conducted using the search terms Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, pulmonary exacerbations, and cystic fibrosis. Study Selection and Data Extraction: All English-language research articles, case reports, and case series were evaluated. A total of 185 articles were identified related to MRSA and CF; 30 articles that studied treatments of MRSA APE in CF were included. Data Synthesis: The persistent presence of MRSA in the respiratory tract of patients with CF has been associated with higher morbidity and an increased risk of death. Limited clinical data exist supporting the efficacy of any specific antimicrobial currently available for the treatment of APE secondary to MRSA. Conclusions: Data extrapolated from other populations suggest that vancomycin and linezolid are appropriate first-line treatment options for the treatment of APE secondary to MRSA. Second-line options include doxycycline or minocycline and trimethoprim/sulfamethoxazole, each of which may be useful in patients coinfected with other respiratory pathogens, for which they may provide overlapping coverage. Ceftaroline and ceftobiprole are newer antibiotics that appear to have a potential role in the treatment of APE in CF, but the latter is not currently available to the US market. Although potentially useful, clindamycin is limited by high rates of resistance, telavancin is limited by its toxicity profile, and tigecycline is limited by a lack of demonstrated efficacy for infections that are similar to that seen in the CF population. Studies investigating the clinical utility of the above-cited antibiotics for APE in CF secondary to MRSA are desperately needed to broaden the treatment armamentarium for this medical condition.

Pediatric anthrax clinical management

Anthrax is a zoonotic disease caused by Bacillus anthracis, which has multiple routes of infection in humans, manifesting in different initial presentations of disease. Because B anthracis has the potential to be used as a biological weapon and can rapidly progress to systemic anthrax with high mortality in those who are exposed and untreated, clinical guidance that can be quickly implemented must be in place before any intentional release of the agent. This document provides clinical guidance for the prophylaxis and treatment of neonates, infants, children, adolescents, and young adults up to the age of 21 (referred to as "children") in the event of a deliberate B anthracis release and offers guidance in areas where the unique characteristics of children dictate a different clinical recommendation from adults.

Linezolid use in hospitalized children

We used the Pediatric Health Information System to evaluate linezolid use among hospitalized children. From 2003 to 2007, use increased 5-fold, including wide interhospital variation, then stabilized through 2011. Linezolid was responsible for 3% of total antibiotic expenditures. Children with respiratory, oncologic or transplant conditions were the most frequently treated with linezolid.

Toxic optic neuropathies

PURPOSE OF REVIEW

Many causes of toxic optic neuropathy have been described to date and novel causes of toxicity are continuously being added to the current literature. The pathophysiological basis for the toxicity or a direct causal relationship is yet to be determined for many of these agents. This review highlights the reports made over the last year about the commonly reported agents, with emphasis on the mechanisms of toxicity.

RECENT FINDINGS

Mitochondria of retinal ganglion cells and papillomacular bundle in particular could be the common target of many causes of toxic optic neuropathy, if not all. Agents or their metabolites responsible for the toxicity seem to interfere with the oxidative phosphorylation in mitochondria, causing a buildup of reactive oxidation species, energy depletion, oxidative stress, and activation of apoptosis.

SUMMARY

Further data are still necessary to understand how some of the usual suspects cause damage to the optic nerve or whether they indeed cause damage or not. A basic algorithm, as proposed, could be a useful addition to discriminate the novel causes of toxic optic neuropathy.

VIDEO ABSTRACT

See the Supplemental Digital Content 1 (http://links.lww.com/COOP/A11).

Nocardiosis in transplant recipients

Nocardiosis is a rare opportunistic infection caused by Nocardia spp., an aerobic actinomycete, that mainly affects patients with cell-mediated immunity defects, such as transplant recipients. Despite recent progress regarding Nocardia identification and changes in taxonomic assignment, many challenges remain for the diagnosis or management of nocardiosis. This opportunistic infection affects 0.04 to 3.5 % of patients with solid organ or hematopoietic stem cell transplantation, depending on the organ transplanted, cytomegalovirus (CMV) infection, corticosteroids dose and calcineurin inhibitors level. Nocardiosis diagnosis relies on appropriate clinical, radiological and microbiological workup that includes the sampling of an accessible involved site and molecular microbiology tools. In parallel, extensive clinical and radiological evaluations are mandatory, including brain imaging, even in the absence of neurological signs. In transplanted patients, differential diagnosis is challenging, with co-infections reported in 20 to 64 % of cases. As the antibiotic susceptibility pattern varies among species, the antimicrobial regimen before species identification should rely on the association of antibiotics active on all species of Nocardia. Bactericidal antibiotics are required in cases of severe or disseminated disease. Furthermore, in transplant recipients, combination therapy is difficult to manage because of cumulative toxicity and interactions with immunosuppressive agents. Because of a high recurrence rate, antibiotic therapy should be prescribed for 6 to 12 months.

Ocular toxicity from systemically administered xenobiotics

INTRODUCTION

The eye is considered as the most privileged organ because of the blood-ocular barrier that acts as a barrier to systemically administered xenobiotics. However, there has been a significant increase in the number of reports on systemic drug-induced ocular complications. If such complications are left untreated, then it may cause permanent damage to vision. Hence, knowledge of most recent updates on ever-increasing reports of such toxicities has become imperative to develop better therapy while minimizing toxicities.

AREAS COVERED

The article is mainly divided into anterior and posterior segment manifestations caused by systemically administered drugs. The anterior segment is further elaborated on corneal complications where as the posterior segment is focused on optic nerve, retinal and vitreous complications. Furthermore, this article includes recent updates on acute and chronic ocular predicaments, in addition to discussing various associated symptoms caused by drugs.

EXPERT OPINION

Direct correlation of ocular toxicities due to systemic drug therapy is evident from current literature. Therefore, it is necessary to have detailed documentation of these complications to improve understanding and predict toxicities. We made an attempt to ensure that the reader is aware of the characteristic ocular complications, the potential for irreversible drug toxicity and indications for cessation.