Intoxicación con monensina en un feedlot de búfalos de Argentina

The aim of this paper was to describe a case of accidental monensin poisoning of feedlot domestic buffalo (Bubalus bubalis) in northeastern Argentina. Clinical signs included anxiety facie with orthopneic position, teeth grinding, diarrhea, muscular weakness, depression and recumbency. In monensin intoxicated animals, a significant increase of creatine phosphokinase and aspartate aminotransferase was observed. At postmortem examination, buffaloes consistently had pale areas that were irregularly distributed in cardiac and skeletal muscles, hydrothorax, congestion and oedema of the lung. Dege-neration and necrosis of the myocardium and skeletal muscle was observed by histological examination. Feed analysis revealed toxic levels of monensin; therefore, ionophore toxicosis was diagnosed. Accordingly, it is required great caution when feeding buffaloes with monensin used as a feed additive.El objetivo de este trabajo fue describir un envenenamiento accidental por monensina en búfalos domésticos (Bubalus bubalis) pertenecientes a un feedlot ubicado en la región nordeste de Argentina. Los signos clínicos incluyeron ansiedad, posición ortopneica con rechinamiento de dientes, diarrea, debilidad muscular, depresión y recumbencia. En los animales expuestos a monensina se observaron aumentos significativos de creatin fosfoquinasa y aspartato aminotransferasa. A la necropsia, los búfalos presentaron áreas pálidas de distribución irregular, hidrotórax, congestión y edema pulmonar. Al examen histológico se observó degeneración y necrosis de músculos cardíaco y esquelético. El análisis del alimento reveló niveles tóxicos de monensina, por lo cual se diagnosticó una toxicosis por ionóforos. A pesar de los efectos positivos de la monensina como fuente de alimento de los animales, se debe requerir un mayor nivel de precaución al alimentar búfalos con ionóforos.Facultad de Ciencias Veterinaria

Benznidazole in cerebrospinal fluid: A case series of chagas disease meningoencephalitis in hiv-positive patients

Chagas disease reactivation in HIV-positive people is an opportunistic infection with 79 to 100% mortality. It commonly involves the central nervous system (CNS). Early treatment with trypanocidal drugs such as benznidazole (BNZ) is crucial for this severe manifestation of Trypanosoma cruzi infection. However, limited BNZ clinical pharmacology data are available, especially its concentration in the CNS. We report a series of HIV-positive patients undergoing treatment for T. cruzi meningoencephalitis, their clinical response, and cerebrospinal fluid (CSF) and plasma BNZ concentrations. Measurements were carried out using leftover samples originally obtained for routine medical care. A high-performance liquid chromatography/tandem mass spectrometry bioanalytical method designed for BNZ plasma measurements was adapted and validated for CSF samples. Six patients were enrolled in this study from 2015 to 2019. A total of 6 CSF and 19 plasma samples were obtained. Only three of the CSF samples had detectable BNZ levels, all under 1mg/ml. Fifteen plasma samples had detectable BNZ, and 13 were above 2mg/ml, which is the putative trypanocidal level. We observed BNZ concentrations in human CSF and plasma. CSF BNZ concentrations were low or not measurable in all patients, suggesting that the usual BNZ doses may be suboptimal in HIV-positive patients with T. cruzi meningoencephalitis. While drug-drug and drug-disease interactions may be in part responsible, the factors leading to low CSF BNZ levels remain to be studied in detail. These findings highlight the potential of therapeutic drug monitoring in BNZ treatment and suggest that the use of higher doses may be useful for Chagas disease CNS reactivations