Rivastigmine prevents injury induced by ischemia and reperfusion in rat liver.

PURPOSE: To evaluate whether pre-treatment with rivastigmine is able to attenuate the I/R induced lesions in rat liver. METHODS: SHAM animals or those submitted to I/R, non-treated or pre-treated with rivastigminine (2mg/kg) either 50 or 15 minutes before ischemia, were used. After I/R protocol, these animals were killed and their livers were harvested to measurement of the mitochondrial swelling as well as the malondialdehyde (MDA), nitrite and nitrate tissue concentration. Blood was also harvested for serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) determinations. RESULTS: I/R promoted a significant increase of mitochondrial swelling in the studied animals. This increase of mitochondrial swelling was partially prevented by rivastigmine, but only if administered 50 minutes before ischemia. No significant modification of MDA, nitrite or nitrate tissue concentrations was observed in consequence of I/R, followed or not by rivastigmine treatments. In addition, I/R elevated both AST and ALT. These elevations of serum enzymes were not reversed by the different rivastigmine treatments. CONCLUSIONS: Rivastigmine administered 50 minutes before ischemia attenuates I/R-induced mitochondrial swelling, that indicates liver injury. This protective effect may be related to a greater stimulation of α7nAChR present in the Kupffer cells by the non-methabolized ACh, leading to an attenuation of I/R-induced inflammation.

Rivastigmine prevents injury induced by ischemia and reperfusion in rat liver

Purpose: To evaluate whether pre-treatment with rivastigmine is able to attenuate the I/R induced lesions in rat liver. Methods: SHAM animals or those submitted to I/R, non-treated or pre-treated with rivastigminine (2mg/kg) either 50 or 15 minutes before ischemia, were used. After I/R protocol, these animals were killed and their livers were harvested to measurement of the mitochondrial swelling as well as the malondialdehyde (MDA), nitrite and nitrate tissue concentration. Blood was also harvested for serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) determinations. Results: I/R promoted a significant increase of mitochondrial swelling in the studied animals. This increase of mitochondrial swelling was partially prevented by rivastigmine, but only if administered 50 minutes before ischemia. No significant modification of MDA, nitrite or nitrate tissue concentrations was observed in consequence of I/R, followed or not by rivastigmine treatments. In addition, I/R elevated both AST and ALT. These elevations of serum enzymes were not reversed by the different rivastigmine treatments. Conclusions: Rivastigmine administered 50 minutes before ischemia attenuates I/R-induced mitochondrial swelling, that indicates liver injury. This protective effect may be related to a greater stimulation of alfa7nAChR present in the Kupffer cells by the non-methabolized ACh, leading to an attenuation of I/R-induced inflammation.(AU)

Rivastigmine prevents injury induced by ischemia and reperfusion in rat liver

Abstract Purpose: To evaluate whether pre-treatment with rivastigmine is able to attenuate the I/R induced lesions in rat liver. Methods: SHAM animals or those submitted to I/R, non-treated or pre-treated with rivastigminine (2mg/kg) either 50 or 15 minutes before ischemia, were used. After I/R protocol, these animals were killed and their livers were harvested to measurement of the mitochondrial swelling as well as the malondialdehyde (MDA), nitrite and nitrate tissue concentration. Blood was also harvested for serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) determinations. Results: I/R promoted a significant increase of mitochondrial swelling in the studied animals. This increase of mitochondrial swelling was partially prevented by rivastigmine, but only if administered 50 minutes before ischemia. No significant modification of MDA, nitrite or nitrate tissue concentrations was observed in consequence of I/R, followed or not by rivastigmine treatments. In addition, I/R elevated both AST and ALT. These elevations of serum enzymes were not reversed by the different rivastigmine treatments. Conclusions: Rivastigmine administered 50 minutes before ischemia attenuates I/R-induced mitochondrial swelling, that indicates liver injury. This protective effect may be related to a greater stimulation of α7nAChR present in the Kupffer cells by the non-methabolized ACh, leading to an attenuation of I/R-induced inflammation.

Actualización en enfermedad con cuerpos de Lewy / Update in Lewy body disease

La enfermedad con cuerpos de Lewy incluye 2 entidades que podrían ser consideradas variantes clínicas de una misma patología: la demencia con cuerpos de Lewy y la demencia en enfermedad de Parkinson. Con la finalidad de describir correctamente lo que sucede en la evolución de la enfermedad se divide el cuadro en etapa prodrómica y de demencia propiamente dicha. La primera está clínicamente representada por aquel período en el cual, si bien el paciente exhibe algunos signos y síntomas propios de la enfermedad, no reúne criterios de demencia. A pesar de ser difícil de definir y por carecerse todavía de contundentes datos clínicos y biomarcadores, se caracteriza principalmente por deterioro leve selectivo en función atencional ­ visuoespacial, trastorno del sueño REM y disautonomía‒. La segunda etapa está claramente caracterizada en los criterios de consenso del año 2005. Recientemente hemos publicado la validación de un instrumento llamado ALBA Screening Instrument, que permite diagnosticar con alta sensibilidad y especificidad la enfermedad aun en etapas tempranas y diferenciarla de otras patologías semejantes. La tomografía por emisión de positrones (PET) para transportador de dopamina es el procedimiento de referencia (gold standard) del diagnóstico. El tratamiento sintomático con anticolinesterásicos y neurolépticos atípicos favorece una buena evolución de la enfermedad y es fundamental tener en cuenta evitar medicamentos que pueden dañar gravemente a los pacientes como los anticolinérgicos y antipsicóticos típicos. Los avances en el diagnóstico y la difusión del impacto de esta enfermedad en la población contribuirán a generar mayores esfuerzos de investigación para hallar un tratamiento eficaz, preventivo o curativo o de ambas características. (AU)

Lewy body disease includes 2 entities that could be considered clinical variants of the same pathology: Dementia with Lewy bodies and Parkinson's disease Dementia. Two stages of the disease are described in this review, a prodromal stage and one of explicit dementia. The first one is clinically represented by that period in which, the patient exhibits some typical features of the disease, but not dementia criteria. Despite being difficult to define the prodromal stage and that strong clinical data and biomarkers are still lacking, there is evidence to characterize it mainly by mild selective impairment in attention and visuo-spatial function, REM sleep disorder and dysautonomia. The second stage is clearly characterized in the known consensus criteria of 2005. We have recently published the validation of an instrument called ALBA Screening Instrument which showed a high sensitivity and specificity for diagnosis of the disease even in the early stages. It´s useful to differentiate the disease from other similar pathologies. Positron Emission Tomography for dopamine transporter is the gold standard of diagnosis in life. Symptomatic treatment with anticholinesterases and atypical neuroleptics help patients in their evolution of the disease. Anticholinergics and typical antipsychotics are agents to avoid in the treatmen of the disease because can severely damage patients. Future advances in the diagnosis and dissemination of the knowledge of the disease will contribute to generate greater research efforts to find an effective preventive and / or curative treatment. (AU)

Development of a Discriminative In Vitro Release Test for Rivastigmine Transdermal Patches Using Pharmacopeial Apparatuses: USP 5 and USP 6.

The aim of this study was to develop and validate a discriminating in vitro release test to evaluate rivastigmine transdermal patches. The Exelon® Patch was chosen as a model transdermal product. The studies of in vitro release were designed to determine the impact of the official apparatus chosen (USP apparatus 5 and USP apparatus 6), the rotation speed, and the dissolution medium characteristics on the rivastigmine release profile from transdermal patches. Patches with different drug release profiles were tested in order to evaluate the discriminating power of the in vitro release test developed and validated. Variables such as the apparatus type, the dissolution medium, and the rotation speed have a significant influence on the drug release characteristics from a transdermal patch. The in vitro release methodologies using the USP apparatus 5 at 50 rpm and USP apparatus 6 at 25 rpm using the medium phosphate-buffered saline pH 7.4 were considered discriminative and adequate to characterize the rivastigmine (RV) release from a commercial transdermal patch, Exelon® Patch.

Effect of Rivastigmine Augmentation in Treatment of Male Patients With Combat-Related Chronic Posttraumatic Stress Disorder: A Randomized Controlled Trial.

BACKGROUND: Posttraumatic stress disorder (PTSD) is one of the chronic and disabling psychiatric disorders, particularly in combat veterans. In a case series, rivastigmine was suggested to be an effective augmentation in treatment of PTSD. The aim of the present study was to evaluate this finding in a randomized controlled trial. METHOD: A 12-week, double-blind, placebo-controlled clinical trial was performed on 36 male patients (aged 42-60 years) diagnosed with chronic, combat-related PTSD. Subjects were screened for apparent cognitive deficits by means of Mini-Mental State Examination. All patients received selective serotonin reuptake inhibitors plus sodium valproate for 4 weeks and then reevaluated. Subjects who did not show adequate response were randomly assigned into 3 groups receiving rivastigmine (up to 6 mg/d), placebo, or the prior treatment regimen. Efficacy of medication was measured by administering PTSD Check List-Military Version at baseline and weeks 2, 4, 8, and 12. Collected data were analyzed by analysis of variance and repeated measurement. Reported differences were considered significant at the level of 0.05 or less. RESULTS: The 3 groups showed statistically significant reductions in the total PTSD Check List-Military Version, avoidance subscale, and the reexperience subscale but not in the hyperarousal subscale. No significant differences were found between the 3 groups. CONCLUSIONS: In contrast to the previous case series, findings of the current study did not support the efficacy of adjunctive rivastigmine in treatment of PTSD. This hypothetically could be due to the fact that all the study's subjects scored higher than 25 on Mini-Mental State Examination.

Comparative evaluation of rivastigmine permeation from a transdermal system in the Franz cell using synthetic membranes and pig ear skin with in vivo-in vitro correlation.

In the present study, in vitro permeation experiments in a Franz diffusion cell were performed using different synthetic polymeric membranes and pig ear skin to evaluate a rivastigmine (RV) transdermal drug delivery system. In vitro-in vivo correlations (IVIVC) were examined to determine the best model membrane. In vitro permeation studies across different synthetic membranes and skin were performed for the Exelon(®) Patch (which contains RV), and the results were compared. Deconvolution of bioavailability data using the Wagner-Nelson method enabled the fraction of RV absorbed to be determined and a point-to-point IVIVC to be established. The synthetic membrane, Strat-M™, showed a RV permeation profile similar to that obtained with pig ear skin (R(2)=0.920). Studies with Strat-M™ resulted in a good and linear IVIVC (R(2)=0.991) when compared with other synthetic membranes that showed R(2) values less than 0.90. The R(2) for pig ear skin was 0.982. Strat-M™ membrane was the only synthetic membrane that adequately simulated skin barrier performance and therefore it can be considered to be a suitable alternative to human or animal skin in evaluating transdermal drug transport, potentially reducing the number of studies requiring human or animal samples.