Caracterización de la utilización de colistín en un hospital de alta complejidad / Evaluation of colistin use in a highly complex hospital

RESUMEN: El aumento de la resistencia y la escasez de nuevos antibacterianos ha requerido la reintroducción de antiguos antimicrobianos entre ellos colistín. OBJETIVO: Caracterizar la utilización de colistín durante el año 2017 en un hospital universitario, mediante la descripción de los pacientes, los tratamientos, la microbiología asociada y efectos adversos. PACIENTES Y MÉTODOS: Trabajo observacional retrospectivo. Se revisaron los datos de todos los pacientes que recibieron colistín intravenoso (IV) por al menos 48 horas, durante el año 2017. RESULTADOS: Se incluyeron 53 pacientes, equivalentes a 91 tratamientos. El foco respiratorio fue el principal (46,2%). El 68,1% de los tratamientos fue iniciado en la UCI. La mayoría de los pacientes tenía una hospitalización reciente (83,5%), y presentaban uso previo de antibacterianos (89%). Los dos patógenos mayoritariamente identificados fueron Pseudomonas aeruginosa y Klebsiella spp. El consumo promedio de colistín fue de 2,4 DDD/100 camas/día. El servicio que más consumió colistín fue la UCI, con 45,5 DDD/100 camas/día, usando generalmente la dosis de 3 MUI cada 8 horas IV y con una baja utilización de dosis de carga. CONCLUSIÓN: Colistín corresponde a un antimicrobiano de uso restringido a infecciones sospechadas o confirmadas por agentes bacterianos multi resistentes. En esta serie, su uso inicial fue principalmente empírico, en pacientes con factores de riesgo para resistencia antibacteriana; se usó en forma asociada a otros antimicrobianos, siendo el foco principal el respiratorio.

BACKGROUND: The increase in resistance and the shortage of new antibiotics has led to the reintroduction of old antimicrobials such as colistin. AIM: To evaluate the use of colistin during 2017 in a university hospital, through the characterization of patients and treatment, associated microbiology, response to treatment and adverse effects. METHODS: Retrospective observational design. The data of all patients who received colistin for at least 48 hours during the year 2017 were reviewed. RESULTS: 55 patients were included, equivalent to 144 treatments. The respiratory focus was the main one (57.9%). 64% of the treatments began in the ICU, while 7% in the ward. Most of the patients has a recent hospitalization (86.8%) and has previous use of antibiotics (90.4%). The two main pathogens identified were Pseudomonas aeruginosa and Klebsiella spp. In 87.1% of the cases with microbiological justifications for the use of colistin, a favorable response was obtained. The average consumption of colistin was 2.4 DDD/100 beds/day. The department that consumed the most colistin was the ICU, with 45,5 DDD/100 beds/day, generally using a dose of 3 MIU every 8 hours IV and with low use of loading doses. CONCLUSION: Colistin corresponds to an antibiotic whose use is restricted to infections suspected or confirmed by multi-resistant bacterial agents. Its initial use in this serie was mainly empirical, in patients with risk factors for antibiotics resistance, it was used in association with other antimicrobials, being the respiratory the main infectious focus.

Eficacia y seguridad de ceftazidima-avibactam en pacientes pediátricos de 3 meses a más con sepsis causada por bacterias Gram-negativas productoras de carbapenemasas y resistentes a colistina / Efficacy and safety of ceftazidime-avibactam in pediatric patients aged 3 months and older with sepsis caused by Gram-negative carbapenemase-producing bacteria resistant to colistin

ANTECEDENTES: En el marco de la metodología ad hoc para evaluar solicitudes de tecnologías sanitarias, aprobada mediante Resolución de Instituto de Evaluación de Tecnologías en Salud e Investigación N° 111-IETSI-ESSALUD-2021 y ampliada mediante Resolución de Instituto de Evaluación de Tecnologías en Salud e Investigación N° 97-IETSI-ESSALUD2022, se ha elaborado el presente dictamen, el cual expone la evaluación de la eficacia y seguridad de ceftazidima-avibactam en pacientes pediátricos de 3 meses a más con sepsis causada por bacterias Gram-negativas productoras de carbapenemasas y resistentes a colistina. Así, el Dr. Michael Algio Quispe Huarcaya y la Dra. Mabel Rubi Carhuana Salazar, médicos especialistas en gastroenterología pediátrica del Hospital Nacional Edgardo Rebagliati Martins (HNERM), siguiendo la Directiva N° 003-IETSIESSALUD-2016, enviaron al Instituto de Evaluación de Tecnologías en Salud e Investigación ­ IETSI las solicitudes de autorización de uso del producto farmacéutico ceftazidima-avibactam no incluido en el Petitorio Farmacológico de EsSalud. ASPECTOS GENERALES: La sepsis se define como una disfunción orgánica potencialmente mortal causada por una respuesta desregulada del huésped a la infección (Pomerantz y Weiss 2022). Se caracteriza por un síndrome de respuesta inflamatoria sistémica (SRIS) en respuesta a una infección, que en pacientes pediátricos consiste en: i) temperatura anormal' y/o recuento anormal de leucocitos, más ii) el ritmo cardiaco anormal2y/o frecuencia respiratoria anormalmente alta' (DynaMed 2022). La sepsis no tratada tempranamente, puede ocasionar daño irreversible a los tejidos, shock séptico, insuficiencia orgánica múltiple y poner en riesgo la vida (OPS 2022). Se estima que la mortalidad hospitalaria en pacientes pediátricos con sepsis es 2 % al 10 %, mientras que en pacientes pediátricos cuya sepsis se complica a sepsis grave (sepsis con disfunción de órganos diana) o shock séptico (sepsis con disfunción cardiovascular), la mortalidad es de 14 % al 50 % (DynaMed 2022; Weiss et al. 2020). METODOLOGÍA Se realizó una búsqueda bibliográfica exhaustiva con el objetivo de identificar la mejor evidencia disponible sobre la eficacia y seguridad de C-A, en comparación con la mejor terapia de soporte, en pacientes pediátricos de 3 meses a más con sepsis causada por bacterias Gram-negativas productoras de carbapenemasas y resistentes a colistina (población objetivo). La búsqueda bibliográfica se llevó a cabo en las bases de datos: PubMed, The Cochrane Library, Web of Science y LILACS. Asimismo, se realizó una búsqueda manual dentro de las páginas web pertenecientes a grupos que realizan evaluación de tecnologías sanitarias (ETS) y guías de práctica clínica (GPC) incluyendo el National Institute for Health and Care Excellence (NICE), la Canadian Agency for Drugs and Technologies in Health (CADTH), el Scottish Medicines Consortium (SMC), el Scottish Intercollegiate Guidelines Network (SIGN), el Institute for Quality and Efficiency in Healthcare (IQWiG por sus siglas en alemán), la International Database of GRADE Guideline, el Centro Nacional de Excelencia Tecnológica en Salud (CENETEC), la Guidelines International Network (GIN), el National Health and Medical Research Council (NHMRC), la Cancer Guidelines Database, el New Zealand Guidelines Group (NZGG), el Instituto de Evaluación Tecnológica en Salud (IETS), el Instituto de Efectividad Clínica y Sanitaria (IECS), la Base Regional de Informes de Evaluación de Tecnologías en Salud de las Américas (BRISA), la Organización Mundial de la Salud y el Ministerio de Salud del Perú (MINSA). Además, se realizó una búsqueda de GPC de las principales sociedades o instituciones especializadas en infectología, tales como: la European Society of Clinical Microbiology and Infectious Diseases (ESCMID), la European Society of Intensive Care Medicine (ESICM), la Pediatric Infectious Diseases Society (PIDS) y la Infectious Diseases Society of America (IDSA). Finalmente, se realizó una búsqueda en la página web de registro de ensayos clínicos (EC) www.clinicaltrials.gov, para identificar EC en curso o que no hayan sido publicados aún. RESULTADOS: Luego de la búsqueda bibliográfica hasta noviembre de 2022, se identificaron dos GPC elaboradas por la IDSA (Tamma et al. 2022) y la ESCMID (Paul et al. 2022), una ETS elaborada por NICE (NICE 2022) y un estudio observacional publicado por Wang et al. (Wang et al. 2022). Cabe mencionar que se excluyeron un ECA (Bradley et al. 2019) y dos GPC (Weiss et al. 2020; NICE 2017). Este ECA fue excluido porque evaluó pacientes pediátricos con infección urinaria complicada donde no se describe si los pacientes presentaron o no sepsis. Además, no se especifica si dichas infecciones fueron o no por bacterias productoras de carbapenemasas o al menos si fueron o no resistentes a carbapenémicos; por lo tanto, no brinda información que permita responder a la pregunta PICO del presente dictamen. Respecto a las GPC, estas dos guías (Weiss et al. 2020; NICE 2017) fueron excluidas porque sus recomendaciones no están dirigidas a la población objetivo del presente dictamen (pacientes con sepsis por bacterias gram-negativas productoras de carbapenemasas). CONCLUSIÓN: Por lo expuesto, el Instituto de Evaluación de Tecnologías en Salud e Investigación aprueba el uso de ceftazidima-avibactam para pacientes pediátricos de 3 meses a más con sepsis causada por bacterias Gram-negativas productoras de carbapenemasas y resistentes a colistina, como producto farmacéutico no incluido en el Petitorio Farmacológico de EsSalud, según lo establecido en el Anexo N° 1. La vigencia del presente dictamen preliminar es de un año a partir de la fecha de publicación. Así, la continuación de dicha aprobación estará sujeta a la evaluación de los resultados obtenidos y de mayor evidencia que pueda surgir en el tiempo.

Amikacin for the treatment of carbapenem-resistant Klebsiella pneumoniae infections: clinical efficacy and toxicity.

Infections by carbapenem-resistant Klebsiella pneumoniae (CRKp) are an increasing global threat with limited therapeutic options. Our objective was to evaluate clinical and microbiological outcomes of patients treated with amikacin for CRKp infections. We did a retrospective cohort of patients > 18 years old, with CRKp infections treated with amikacin in two tertiary care hospitals in Porto Alegre, Brazil. The impact of clinical factors, antibiotic treatment, and amikacin minimum inhibitory concentration (MIC) on patients' 30-day mortality was assessed. Microbiological clearance and nephrotoxicity (assessed by RIFLE score) were evaluated as secondary outcomes. A Cox regression analysis was done for mortality. We included 84 patients for analysis. Twenty-nine (34.5%) patients died in 30 days. Amikacin MIC values ranged from 0.125 to 8 µg/mL and did not influence on mortality, regardless of the prescribed dose of this antibiotic (P = 0.24). Bacterial clearance occurred in 17 (58.6%) of 29 patients who collected subsequent cultures. Two (16.6%) of the 12 persistently positive cultures changed the amikacin susceptibility profile from susceptible to intermediate. Twenty-nine (37.2%) patients developed acute kidney injury (AKI): risk 13, injury 11, and failure 5. Risk factors for AKI were higher baseline eGFR (P < 0.01) and combination therapy with colistin (P = 0.02). Comparing patients who received combination with colistin vs polymyxin B, AKI occurred in 60.0% vs 20.6%, respectively, P < 0.01. Fifteen of the 16 (16.6%) patients who developed renal injury or failure were receiving colistin. In conclusion, amikacin was an effective treatment for CRKp infections. Within susceptible range, amikacin MIC values did not influence on clinical outcomes. Combination therapy of amikacin and colistin was highly nephrotoxic and should be used with caution.

Optimal control for colistin dosage selection.

Optimization of antibiotic administration helps minimizing cases of bacterial resistance. Dosages are often selected by trial and error using a pharmacokinetic (PK) model. However, this is limited to the range of tested dosages, restraining possible treatment choices, especially for the loading doses. Colistin is a last-resort antibiotic with a narrow therapeutic window; therefore, its administration should avoid subtherapeutic or toxic concentrations. This study formulates an optimal control problem for dosage selection of colistin based on a PK model, minimizing deviations of colistin concentration to a target value and allowing a specific dosage optimization for a given individual. An adjoint model was used to provide the sensitivity of concentration deviations to dose changes. A three-compartment PK model was adopted. The standard deviation between colistin plasma concentrations and a target set at 2 mg/L was minimized for some chosen treatments and sample patients. Significantly lower deviations from the target concentration are obtained for shorter administration intervals (e.g. every 8 h) compared to longer ones (e.g. every 24 h). For patients with normal or altered renal function, the optimal loading dose regimen should be divided into two or more administrations to attain the target concentration quickly, with a high first loading dose followed by much lower ones. This regimen is not easily obtained by trial and error, highlighting advantages of the method. The present method is a refined optimization of antibiotic dosage for the treatment of infections. Results for colistin suggest significant improvement in treatment avoiding subtherapeutic or toxic concentrations.

Eficacia y seguridad de ceftazidima-avibactam para el tratamiento de pacientes adultos con neumonía intrahospitalaria asociada a ventilación mecánica causada por bacterias gram negativas productoras de carbapenemasas y resistentes a colistina / Efficacy and safety of ceftazidime-avibactam for the treatment of adult patients with hospital-acquired pneumonia associated with mechanical ventilation caused by colistin-resistant gram-negative carbapenemase-producing bacteria

INTRODUCCIÓN: El presente dictamen expone la evaluación de la eficacia y seguridad de ceftazidima-avibactam (C-A) para el tratamiento de pacientes adultos con neumonía intrahospitalaria asociada a ventilación mecánica (NAVM) causada por bacterias gram negativas productoras de carbapenemasas y resistentes a colistina. La neumonía intrahospitalaria es la principal causa de muerte por infecciones adquiridas en el hospital. Aproximadamente, el 80 % de las neumonías intrahospitalarias corresponden a neumonías intrahospitalarias asociadas a ventilador mecánico (NAVM) con una mortalidad que puede llegar al 76 %, cuando la infección es causada por patógenos de alto riesgo. Actualmente, existen patógenos gram negativos extremadamente resistentes que producen betalactamasas capaces de hidrolizar antibióticos carbapenémicos llamados bacterias gram negativas productoras de carbapenemasas. Hasta la fecha, existen pocas alternativas para el tratamiento de NAVM causada por bacterias productoras de carbapenemasas. Como opciones de última línea, se tienen esquemas basados en colistina más carbapenémicos. En EsSalud, estos pacientes tienen a su disposición esta combinación como última línea de tratamiento; sin embargo, algunos pacientes presentan infecciones resistentes a estos antibióticos, por lo cual no disponen de una alternativa terapéutica para controlar la infección. Así, los especialistas de EsSalud sugieren el uso de ceftazidima-avibactam (C-A) para el tratamiento de la NAVM por bacterias gram negativas productoras de carbapenemasas y resistentes a colistina. La ceftazidima es una cefalosporina que inhibe la síntesis de la pared celular bacteriana, y el avibactam es un inhibidor de beta-lactamasa. Ambos son antibióticos cuya presentación en forma combinada ha sido aprobada por la Food and Drug Administration (FDA) y la European Medicines Agency (EMA) para el tratamiento de pacientes NAVM ocasionado por bacterias gram negativas. METODOLOGÍA: Se llevó a cabo una búsqueda bibliográfica exhaustiva con el objetivo de identificar la mejor evidencia sobre la eficacia y seguridad de C-A para el tratamiento de pacientes adultos con NAVM causada por bacterias gram negativas productoras de carbapenemasas y resistentes a colistina. La búsqueda se inició con la revisión de la información sobre el uso del medicamento de acuerdo con entidades reguladoras como FDA, EMA, DIGEMID y la Organización Mundial de la Salud (OMS). La búsqueda bibliográfica se realizó en las bases de datos PubMed, The Cochrane Library y LILACS. Asimismo, se realizó una búsqueda manual dentro de las páginas web pertenecientes a grupos que realizan evaluación de tecnologías sanitarias y guías de práctica clínica (GPC) incluyendo la National Institute for Health and Care Excellence (NICE), Canadian Agency for Drugs and Technologies in Health (CADTH), Scottish Medicines Consortium (SMC), Scottish Intercollegiate Guidelines Network (SIGN), Institute for Clinical and Economic Review (ICER), El Instituto de Calidad y Eficiencia en la Atención de la Salud (IQWiG, por sus siglas en alemán), la Base Regional de Informes de Evaluación de Tecnologías en Salud de las Américas (BRISA), la OMS, el Ministerio de Salud del Perú (MINSA) y el Instituto de Evaluación de Tecnologías en Salud e Investigación (IETSI). Además, se realizó una búsqueda de GPC de las principales sociedades o instituciones especializadas en infectología, tales como: Infectious Diseases Society of America (IDSA), European Respiratory Society (ERS), European Society of Intensive Care Medicine (ESICM), European Society of Clinical Microbiology and Infectious Diseases (ESCMID) y la Asociación Latinoamericana del Tórax (ALAT). Finalmente, se realizó una búsqueda en la página web de registro de ensayos clínicos (EC) www.clinicaltrials.gov, para identificar EC en curso o que no hayan sido publicados aún. RESULTADOS: Se llevó a cabo una búsqueda de evidencia científica relacionada al uso de C-A como tratamiento de pacientes adultos con NAVM causada por bacterias gram negativas productoras de carbapenemasas y resistentes a colistina. La presente sinopsis describe la evidencia disponible según el tipo de publicación, siguiendo lo indicado en los criterios de elegibilidad (GPC, ETS, RS con o sin meta análisis o metaanálisis en red y estudios primarios) que se obtuvieron de la búsqueda sistemática y la búsqueda adicional realizada en PubMed. CONCLUSIONES:  El presente dictamen preliminar tuvo por objetivo evaluar la mejor evidencia disponible en torno a la eficacia y seguridad de C-A en comparación la mejor terapia de soporte (continuar con carbapenémicos, colistina u otros), como tratamiento de pacientes adultos con NAVM causada por bacterias gram negativas productoras de carbapenemasas y resistentes a colistina. No se identificaron GPC, ETS, RS o ECA que respondan a la pregunta PICO del presente dictamen. Tras ampliar los criterios de búsqueda y selección considerando los términos relacionados a la intervención y agentes gram negativos resistentes a carbapenémicos, se identificaron 4 estudios observacionales comparativos que incluían a la población de la pregunta PICO del presente dictamen. De los cuatro estudios incluidos, dos mostraron diferencia a favor de C-A en términos de mortalidad, tres reportaron respuesta clínica a favor de C-A y uno mostró mayor erradicación microbiológica a favor de C-A. Además, dos estudios que evaluaron seguridad estimaron que C-A tendría un mejor perfil de seguridad (menor daño renal) que otros antibióticos (entre ellos carbapenémicos y colistina). Debido al diseño y las limitaciones de estos estudios observacionales, no es posible establecer una relación causa-efecto entre el uso de C-A y los desenlaces evaluados. Sin embargo, sí nos ofrecen una descripción de la actividad antibacteriana y el perfil de seguridad de C-A. La NAVM es una enfermedad con alta mortalidad y los pacientes con NAVM por bacterias gram negativas productoras de carbapenemasas y resistentes a colistina, no cuentan con una alternativa de tratamiento (vacío terapéutico) en EsSalud. La mejor terapia de soporte (continuar con carbapenémicos, colistina u otros disponibles en EsSalud), aumentaría el riesgo de desarrollar eventos adversos y resistencia bacteriana. Dicha resistencia bacteriana pone en riesgo a otros pacientes hospitalizados de adquirir infecciones resistentes, además incrementaría la estancia hospitalaria, los costos de atención y la mortalidad. Por lo expuesto, el IETSI aprueba el uso de C-A en pacientes pacientes adultos con NAVM causada por bacterias gram negativas productoras de carbapenemasas y resistentes a colistina, como producto farmacéutico no incluido en el Petitorio Farmacológico de EsSalud. La vigencia del presente dictamen es de un año, según lo establecido en el Anexo N° 1 y la continuación de dicha aprobación estará sujeta a la evaluación de los resultados obtenidos y de mayor evidencia que pueda surgir en el tiempo.

Nephrotoxicity prevalence in patients treated with polymyxins: a systematic review with meta-analysis of observational studies.

Colistin and polymyxin B are increasingly reintroduced in clinical practice due to the absence of effective antibiotics for the treatment of emerging infections caused by gram-negative bacteria. The synthesis of current evidence on the characteristics of polymyxins, especially regarding nephrotoxicity, is necessary. This study aims to conduct a systematic review and meta-analysis of cohort-type observational studies in order to identify the prevalence of nephrotoxicity in patients treated with either colistin or polymyxin B. PubMed, Scopus, and DOAJ electronic databases were searched, and manual searches were done. Cohort studies evaluating renal damage (nephrotoxicity) in adult patients caused by colistin or polymyxin B were included. Meta-analyses of the prevalence of nephrotoxicity as well as cumulative meta-analysis and meta-regression were conducted. After the systematic searches, 95 cohorts (n = 7911 patients) were included for analysis. The nephrotoxicity prevalence was 26.7% [confidence interval (CI) 95%: 22.8-30.9%] for colistin and 29.8% (CI 23.8-36.7%) for polymyxin B (P = 0.720). The publication year of the studies, the criteria used to classify renal damage, and the nephrotoxicity as primary or secondary outcome showed a significant influence on the adverse event rates.

Colistin induced neurotoxity: a case report and review of literature / Neurotoxicidade induzida pela colistina: relato de caso e revisão de literatura

OBJECTIVE: To describe a case of neurotoxity associated to Colistin. CASE DESCRIPTION: A 29-year-old black male under treatment for urinary tract infection with identification of Klebsiella pneumoniae in urine culture resistant to all carbapenem antibiotics, presented visual turbidity, paresthesia on the face and upper left limb, slowed and discordant speech in the fourth day of Colistin use. Symptoms improved after reduction of the dose of colistin with adjustment for renal function, with complete reversion after discontinuation of the drug. CONCLUSIONS: Colistin-mediated neurotoxicity must be suspected in patients with altered mental status of unknown etiology and therapy promptly interrupted.

OBJETIVO: Descrever um caso de neurotoxidade associada à Colistina. DESCRIÇÃO DO CASO (desnecessário repetição): Um homem negro de 29 anos sob tratamento para infecção do trato urinário com identificação de Klebsiella pneumoniae (escrever corretamente) em cultura de urina resistente a carbapenêmicos, apresentou turvação visual, parestesia em face e membro superior esquerdo, discurso lento e discordante na quarto dia de uso da Colistina. Os sintomas melhoraram após a redução da dose de colistina com ajuste para a função renal, com reversão completa após a descontinuação do fármaco. CONCLUSÕES: A neurotoxicidade mediada por colistina deve ser suspeitada em pacientes com estado mental alterado de etiologia desconhecida e a terapia prontamente interrompida.

Evaluation of growth performance and gastro-intestinal parameters on the response of weaned piglets to dietary organic acids

ABSTRACT Two experiments (E) were carried out to evaluate the effects of fumaric acid and an acidifier blend [composed by calcium formate, calcium lactate and medium-chain fatty acids (capric and caprylic)] in piglet diets containing colistin (40 ppm) or halquinol (120 ppm) on performance, diarrhea incidence (E1), organs relative weight, pH values, intestinal morphometry and microbiota (E2). In E1, 192 and E2, 24 piglets weaned at 21-day-old were randomly assigned to blocks with 2x2 factorial arrangement of treatments [absence or presence of fumaric acid x absence or presence of acidifier blend], six replicates of eight (E1) and one piglet per pen (E2). For E1, the treatments were control (CD): no acidifier product + 40 ppm of colistin, FA: fumaric acid in absence of acidifier blend, AB: acidifier blend in absence of fumaric acid and, AF+AB: presence of fumaric acid and acidifier blend. For E2, the pre-starter I diet were used and the same treatments as E1 evaluated. No treatment effects (P>0.05) were observed on performance, diarrhea incidence (E1), gut pH values and duodenum morphometry of piglets (E2). However, the addition of AB increased (P<0.05) large intestine relative weight and, FA addition decreased (P<0.05) pancreas relative weight, jejunum villi height and, total coliform and E. coli counts in cecum. The inclusion of FA and AB in diets containing colistin or halquinol did not improve performance, although FA exerted an inhibitory effect on cecum microbiota.

Evaluation of growth performance and gastro-intestinal parameters on the response of weaned piglets to dietary organic acids.

Two experiments (E) were carried out to evaluate the effects of fumaric acid and an acidifier blend [composed by calcium formate, calcium lactate and medium-chain fatty acids (capric and caprylic)] in piglet diets containing colistin (40 ppm) or halquinol (120 ppm) on performance, diarrhea incidence (E1), organs relative weight, pH values, intestinal morphometry and microbiota (E2). In E1, 192 and E2, 24 piglets weaned at 21-day-old were randomly assigned to blocks with 2x2 factorial arrangement of treatments [absence or presence of fumaric acid x absence or presence of acidifier blend], six replicates of eight (E1) and one piglet per pen (E2). For E1, the treatments were control (CD): no acidifier product + 40 ppm of colistin, FA: fumaric acid in absence of acidifier blend, AB: acidifier blend in absence of fumaric acid and, AF+AB: presence of fumaric acid and acidifier blend. For E2, the pre-starter I diet were used and the same treatments as E1 evaluated. No treatment effects (P>0.05) were observed on performance, diarrhea incidence (E1), gut pH values and duodenum morphometry of piglets (E2). However, the addition of AB increased (P<0.05) large intestine relative weight and, FA addition decreased (P<0.05) pancreas relative weight, jejunum villi height and, total coliform and E. coli counts in cecum. The inclusion of FA and AB in diets containing colistin or halquinol did not improve performance, although FA exerted an inhibitory effect on cecum microbiota.

Chronic kidney disease after acute kidney injury associated with intravenous colistin use in survivors of severe infections: A comparative cohort study.

PURPOSE: The use of colistin for multi-drug resistant (MDR) infections has led to an increase of colistin-associated acute kidney injury (AKI). Nevertheless, information on long-term renal prognosis is scarce. We aimed to determine the predictors of chronic kidney disease (CKD) in survivors of MDR-infections with colistin-associated AKI. METHODS: A retrospective cohort of patients with colistin-associated AKI was compared with controls (survivors of severe infections who developed AKI matched by age, sex, diabetes, vancomycin exposure, and baseline kidney function). The primary outcome was the development of CKD after 6months of follow-up. RESULTS: From 2011 to 2015, 122 patients with MDR infections received colistin. Among 72 survivors, 29 (40%) had colistin-associated AKI. After 6months, 22 of them (75%) progressed to CKD (G3 in 21/22) compared with 16 (27%) in 58 controls (P<0.001). Independent predictors of progression to CKD were colistin use [odds ratio (OR): 8.86; 95% CI: 2.8-27.8] and age (OR: 1.04, 95% CI: 1.01-1.07). In patients exposed to colistin, a total dose of colistin >5g was an independent predictor of progression to CKD (OR: 14.1, 95% CI: 2.6-75.7). CONCLUSION: Colistin-associated AKI had a substantial risk for the latter development CKD, and consequently, these patients should be tightly monitored.

Nephrotoxicity of Polymyxins: Is There Any Difference between Colistimethate and Polymyxin B?

Nephrotoxicity is a common adverse effect of the clinically used polymyxins, colistin and polymyxin B. This adverse effect is dose limiting for both polymyxins, as the plasma polymyxin concentrations associated with renal damage overlap those required for antibacterial effect. Since development of acute kidney injury (AKI) during therapy is highly undesirable, it is extremely important to know whether there is any difference between the nephrotoxic potential of colistin (administered as its inefficient prodrug, colistimethate) and polymyxin B (administered as the active form). Both polymyxins are cytotoxic to renal tubular cells and are prone to cause nephrotoxicity in vivo because of the renal handling mechanisms that facilitate accumulation of these compounds in these cells, processes that are reviewed in this article. Also reviewed are the emerging data that strongly suggest significantly higher rates of AKI in patients treated with colistimethate compared to patients treated with polymyxin B. This finding may be due to differences in pharmacokinetics and renal handling mechanisms of colistimethate and formed colistin versus polymyxin B, and consequently the relative amount of polymyxin material delivered to tubular cells. A lower risk of AKI with polymyxin B is one of several potential advantages over colistimethate. The relative safety and efficacy of the two agents require closer examination in well-designed clinical studies.

Multicenter Prospective Cohort Study of Renal Failure in Patients Treated with Colistin versus Polymyxin B.

Nephrotoxicity is the main adverse effect of colistin and polymyxin B (PMB). It is not clear whether these two antibiotics are associated with different nephrotoxicity rates. We compared the incidences of renal failure (RF) in patients treated with colistimethate sodium (CMS) or PMB for ≥48 h. A multicenter prospective cohort study was performed that included patients aged ≥18 years. The primary outcome was renal failure (RF) according to Risk, Injury, Failure, Loss, and End-stage renal disease (RIFLE) criteria. Multivariate analysis with a Cox regression model was performed. A total of 491 patients were included: 81 in the CMS group and 410 in the PMB group. The mean daily doses in milligrams per kilogram of body weight were 4.2 ± 1.3 and 2.4 ± 0.73 of colistin base activity and PMB, respectively. The overall incidence of RF was 16.9% (83 patients): 38.3% and 12.7% in the CMS and PMB groups, respectively (P< 0.001). In multivariate analysis, CMS therapy was an independent risk factor for RF (hazard ratio, 3.35; 95% confidence interval, 2.05 to 5.48;P< 0.001) along with intensive care unit admission, higher weight, older age, and bloodstream and intraabdominal infections. CMS was also independently associated with a higher risk of RF in various subgroup analyses. The incidence of RF was higher in the CMS group regardless of the patient baseline creatinine clearance. The development of RF during therapy was not associated with 30-day mortality in multivariate analysis. CMS was associated with significantly higher rates of RF than those of PMB. Further studies are required to confirm our findings in other patient populations.

Risk factors for acute kidney injury in patients treated with polymyxin B or colistin methanesulfonate sodium.

Polymyxin B (PMB) and colistin, administered as the prodrug colistin methanesulfonate sodium (CMS), are increasingly used to treat carbapenem-resistant Gram-negative bacteria. Nephrotoxicity is the major dose-limiting adverse effect of both polymyxins. A retrospective cohort study of 132 patients was conducted to evaluate risk factors for acute kidney injury (AKI), classified according to Acute Kidney Injury Network criteria, in patients treated with ≥48h of intravenous PMB or CMS, with particular focus on potential differences between each polymyxin. The overall incidence of AKI was 25.8% (34/132) [20.8% (20/96) and 38.9% (14/36) in patients treated with PMB and CMS, respectively; P=0.06]. In the Cox regression model, doses ≥2million International Units (MIU) of PMB or >9MIU of CMS were the only variable independently associated with AKI [adjusted hazard ratio (aHR)=2.11, 95% confidence interval (CI) 1.01-4.41; P=0.04]. Vancomycin co-administration was strongly associated with AKI, although this was not statistically significant (aHR=2.22, 95% CI 0.98-5.04; P=0.058). There was no statistically significant difference in the incidence of AKI between patients treated with PMB or CMS in the multivariate model (aHR=1.74, 95% CI 0.82-3.69; P=0.15). High dose was the main risk factor for AKI regardless of the polymyxin administered. Vancomycin co-administration likely increases the risk of AKI. Although there was a higher overall incidence of AKI in patients treated with CMS compared with PMB, CMS was not significantly associated with this outcome after adjusting for the above variables.

Colistina parenteral no tratamento de infeccoes graves: experiencia em centro unico / Parenteral colistin for the treatment of severe infections: a single center experience

Objetivo: Descrever a experiência de um único centro com o uso de colistina para tratar infecções hospitalares causadas por bactérias Gram-negativas resistentes a múltiplos fármacos e identificar fatores associados com lesão renal aguda e mortalidade. Métodos: Estudo longitudinal retrospectivo que avaliou pacientes gravemente enfermos, com infecções causadas por bactérias Gram-negativas resistentes a múltiplos fármacos. Foram considerados elegíveis para este estudo, durante o período compreendido entre janeiro e dezembro de 2008, todos os pacientes adultos com necessidade de tratamento com colistina endovenosa (colistimetato de sódio). As informações coletadas incluem dados demográficos, diagnóstico, duração do tratamento, presença de lesão renal aguda e mortalidade em 30 dias. Resultados: A colistina foi utilizada para tratar uma infecção em 109 de 789 pacientes (13,8%) admitidos à unidade de terapia intensiva. A mortalidade em 30 dias observada nestes pacientes foi de 71,6%. Vinte e nove pacientes (26,6%) tinham lesão renal prévia ao tratamento com colistina, sendo que seis deles conseguiram recuperar a função renal, mesmo durante o tratamento com colistina. Vinte e um pacientes (19,2%) desenvolveram lesão renal aguda durante o tratamento com colistina, sendo que 11 destes pacientes necessitaram ser submetidos à diálise. A variável independentemente associada com a presença de lesão renal aguda foi a pontuação segundo o sistema Sequential Organ Failure Assessment no início do tratamento com colistina (OR=1,46; IC95%=1,20-1,79; p<0,001). Idade (OR=1,03; IC95%=1,00-1,05; p=0,02) e uso de vasopressores (OR=12,48; IC95%=4,49-34,70; p<0,001) foram fatores associados a óbito, segundo um modelo de regressão logística. ...

Objective: To describe a single center experience involving the administration of colistin to treat nosocomial infections caused by multidrug-resistant Gram-negative bacteria and identify factors associated with acute kidney injury and mortality. Methods: This retrospective longitudinal study evaluates critically ill patients with infections caused by multidrug-resistant Gram-negative bacteria. All adult patients who required treatment with intravenous colistin (colistimethate sodium) from January to December 2008 were considered eligible for the study. Data include demographics, diagnosis, duration of treatment, presence of acute kidney injury and 30-day mortality. Results: Colistin was used to treat an infection in 109 (13.8%) of the 789 patients admitted to the intensive care unit. The 30-day mortality observed in these patients was 71.6%. Twenty-nine patients (26.6%) presented kidney injury prior to colistin treatment, and six of these patients were able to recover kidney function even during colistin treatment. Twenty-one patients (19.2%) developed acute kidney injury while taking colistin, and 11 of these patients required dialysis. The variable independently associated with the presence of acute kidney injury was the Sequential Organ Failure Assessment at the beginning of colistin treatment (OR 1.46; 95%CI 1.20-1.79; p<0.001). The factors age (OR 1.03; 95%CI 1.00-1.05; p=0.02) and vasopressor use (OR 12.48; 95%CI 4.49-34.70; p<0.001) were associated with death in the logistic-regression model. Conclusions: Organ dysfunction at the beginning of colistin treatment was associated with acute kidney injury. In a small group of patients, we were able to observe an improvement of kidney function during colistin treatment. Age and vasopressor use were associated with death. .

Parenteral colistin for the treatment of severe infections: a single center experience.

OBJECTIVE: To describe a single center experience involving the administration of colistin to treat nosocomial infections caused by multidrug-resistant Gram-negative bacteria and identify factors associated with acute kidney injury and mortality. METHODS: This retrospective longitudinal study evaluates critically ill patients with infections caused by multidrug-resistant Gram-negative bacteria. All adult patients who required treatment with intravenous colistin (colistimethate sodium) from January to December 2008 were considered eligible for the study. Data include demographics, diagnosis, duration of treatment, presence of acute kidney injury and 30-day mortality. RESULTS: Colistin was used to treat an infection in 109 (13.8%) of the 789 patients admitted to the intensive care unit. The 30-day mortality observed in these patients was 71.6%. Twenty-nine patients (26.6%) presented kidney injury prior to colistin treatment, and six of these patients were able to recover kidney function even during colistin treatment. Twenty-one patients (19.2%) developed acute kidney injury while taking colistin, and 11 of these patients required dialysis. The variable independently associated with the presence of acute kidney injury was the Sequential Organ Failure Assessment at the beginning of colistin treatment (OR 1.46; 95%CI 1.20-1.79; p<0.001). The factors age (OR 1.03; 95%CI 1.00-1.05; p=0.02) and vasopressor use (OR 12.48; 95%CI 4.49-34.70; p<0.001) were associated with death in the logistic-regression model. CONCLUSIONS: Organ dysfunction at the beginning of colistin treatment was associated with acute kidney injury. In a small group of patients, we were able to observe an improvement of kidney function during colistin treatment. Age and vasopressor use were associated with death.

Utilidad de los antibióticos inhalados: más allá de la fibrosis quística / Inhaled antibiotic utility: more than cystic fibrosis

Inhalatory therapy is the preferred way for drugs targeting the lung, which permits to avoid adverse events associated to systemic use. Cystic fibrosis (CF) is the disease with the highest use of inhaled antibiotics, which has provided information extrapoled to other pathologies such as non-CF bronchiectasis and pneumonia associated to mechanical ventilation. The most studied antibiotics currently available in the market are tobramycin and colystin, both inhaled. This article analyzes the updated evidence and recommendations published regarding the use of inhaled antibiotics.

La terapia inhalatoria es la vía de elección para la administración de fármacos cuyo órgano diana es el pulmón, pues evita los efectos adversos asociados a su uso sistémico. La fibrosis quística (FQ) es la enfermedad en que se ha centrado la mayor utilización de antibióticos inhalados, aportando información que se ha extrapolado a otras patologías como las bronquiectasias no FQ y la neumonía asociada a ventilación mecánica. Los antibióticos más estudiados y actualmente disponibles en el mercado son la tobramicina y colistín inhalados. Este artículo revisa la evidencia actualizada y las recomendaciones publicadas en torno al uso de antibióticos por vía inhalatoria.

Polymyxin B and colistimethate are comparable as to efficacy and renal toxicity.

We compared 41 patients who received colistimethate with 41 who received polymyxin B for the treatment of serious infections caused by carbapenem-resistant Acinetobacter spp. and found both polymyxins have similar efficacy and toxicity.

Nephrotoxicity associated with the use of intravenous colistin.

We retrospectively assessed the renal toxicity associated with the use of intravenous colistin. Fifty-four patients with multidrug-resistant Acinetobacter infections were included. At the end of therapy 6/54 patients (11%) suffered renal impairment. Renal impairment associated with the use of colistin is less frequent than initially reported.