The effects of memantine on recovery, cognitive functions, and pain after propofol anesthesia / Efeitos da memantina sobre a recuperação, funções cognitivas e dor após a anestesia com propofol

Abstract Objectives: Postoperative cognitive dysfunction refers to the problems associated with thought and memory that are often experienced after major surgery. The aim of this study is to evaluate the effects of intraperitoneally administered memantine on recovery, cognitive functions, and pain after propofol anesthesia. Methods: The study was conducted in Gazi University Animal Research Laboratory, Ankara, Turkey in January 2012. Twenty-four adult female Wistar Albino rats weighing 170-270 g were educated for 300 s in the radial arm maze (RAM) over three days. Group P was administered 150 mg kg−1 of intraperitoneal (IP) propofol; Group M was given 1 mg kg−1 of IP memantine; and Group MP was given 1 mg kg−1 of IP memantine before being administered 150 mg kg−1 of IP propofol. The control group received only IP saline. RAM and hot plate values were obtained after recovery from the groups that received propofol anesthesia and 30 min after the administration of drugs in other two groups. Results: The duration of recovery for Group MP was significantly shorter than Group P (p < 0.001), and the number of entries and exits in the RAM by Group MP was significantly higher during the first hour when compared to Group P (p < 0.0001). Hot plate values, on the other hand, were found to be significantly increased in all groups when compared to the control values, aside from Group C (p < 0.0001). Conclusion: In this study, memantine provided shorter recovery times, better cognitive functions, and reduced postoperative pain. From this study, we find that memantine has beneficial effects on recovery, cognitive functions, and pain after propofol anesthesia.

Resumo Objetivos: A disfunção cognitiva no pós-operatório refere-se a problemas associados ao pensamento e à memória que são frequentemente manifestados após uma cirurgia de grande porte. O objetivo deste estudo foi avaliar os efeitos da memantina administrada por via intraperitoneal sobre a recuperação, as funções cognitivas e a dor após a anestesia com propofol. Métodos: O estudo foi feito no Laboratório de Pesquisa com Animais da Universidade de Gazi, Ankara, Turquia, em janeiro de 2012. Vinte e quatro ratos albinos do sexo feminino, adultos, da linhagem Wistar, com 170-270 g, foram treinados durante 300 segundos no labirinto radial de oito braços (LRB) durante três dias. O Grupo P recebeu 150 mg/kg−1 de propofol por via intraperitoneal (IP), o Grupo H recebeu 1 mg/kg−1 de memantina IP e o Grupo MP recebeu 1 mg/kg−1 de memantina IP antes da administração de 150 mg/kg−1 de propofol (IP). O grupo controle recebeu apenas solução salina IP. Os valores do LRB e da placa quente foram obtidos após a recuperação dos grupos que receberam propofol e 30 minutos após a administração dos fármacos nos outros dois grupos. Resultados: O tempo de recuperação do Grupo MP foi significativamente menor do que o do Grupo P (p < 0,001) e o número de entradas e saídas do LRB do Grupo MP foi significativamente maior durante a primeira hora, em comparação com o Grupo P (p < 0,0001). Os valores da placa quente, por outro lado, foram significativamente maiores em todos os grupos, em comparação com os valores do grupo controle, exceto pelo Grupo C (p < 0,0001). Conclusão: No presente estudo, memantina proporcionou tempos mais curtos de recuperação, funções cognitivas melhores e reduziu a dor no pós-operatório. A partir deste estudo, descobrimos que a memantina tem efeitos benéficos sobre a recuperação, as funções cognitivas e a dor após anestesia com propofol.

[Effect of memantine administration within the nucleus accumbens on changes in weight and volume of the brain and adrenal gland during chronic stress in female mice]

In the present study, we examined the effects of memantine administration within the nucleus accumbens on the alterations in brain and adrenal volumes and weight ratios induced by stress from electric foot shock. A group of mice received various doses of memantine [0.1, 0.5 and 1 mg/kg] prior to induction of stress. Another group underwent intra-accumbal cannulation after anesthesia. One week later, memantine [0.1, 0.5 and 1 micro g/mouse] was injected within the nucleus accumbens prior to induction of stress. Subsequently all animals were killed. Their brains and adrenal glands were removed and fixed in 4% formalin. The volume and weight was determined by mercury immersion and method respectively. The stress group showed evidence of reduction in brain volume and weight ratio to volume, and weight of the adrenal gland. Memantine increased the ratio of the brain volume and weight to the volume and weight of the adrenal gland. Memantine administration within the nucleus accumbens also could alter this ratio. Hence, all three doses of memantine that were injected on the right side and bilateral to the nucleus inhibited the effects of stress. Inhibition of NMDA receptors in the nucleus accumbens can inhibit the destructive effects of chronic stress on brain volume and weight. In addition, memantine can inhibit the influence of stress on adrenal volume and weight. We have shown that this effect was both dose and injection site dependent. In this regard, the left side of the nucleus was weaker

Efectividad y seguridad de donepezilo, galantamina y memantina para el tratamiento de la Enfermedad de Alzheimer / Effectiveness and safety of donepezil, galantamine and memantine for the treatment of Alzheimer's disease

Antecedentes: Descripción de la condición de salud de interés: Las demencias son un grupo de trastornos del sistema nervioso central, caracterizados por alteración de la memoria, de las funciones ejecutivas, déficit cognitivo y cambios en la personalidad. La Enfermedad de Alzheimer es un tipo de demencia de inicio insidioso y progresión lenta, que compromete la memoria, el lenguaje, la personalidad y la función ejecutiva. Descripción de la tecnología: En general los medicamentos empleados en la enfermedad de Alzheimer ayudan a controlar los síntomas y manejar la agitación, la depresión o los síntomas psicóticos (alucinaciones o delirios) que pueden ocurrir cuando la enfermedad progresa. Evaluación de efectividad y seguridad: Pregunta de investigación: ¿Cuál es la efectividad y seguridad de donepezilo, memantina y galantamina comparado con rivastigmina para el tratamiento de la demencia por enfermedad de Alzheimer? La pregunta de investigación fue refinada y validada con base en: autorización de mercadeo de la tecnología para la indicación de interés (registro sanitario INVIMA), listado de medicamentos vitales no disponibles, cobertura de las tecnologías en el Plan Obligatorio de Salud (POS) (Acuerdo 029 de 2011), revisión de grupos terapéuticos (código ATC: Anatomical, Therapeutic, Chemical classification system), recomendaciones de guías de práctica clínica actualizadas, disponibilidad de evidencia sobre efectividad y seguridad (reportes de evaluación de tecnologías, revisiones sistemáticas de la literatura), uso de las tecnologías (listas nacionales de recobro, estadísticas de prescripción, entre otros), estudios de prevalencia/incidencia y carga de enfermedad y consulta con expertos temáticos (especialistas clínicos), sociedades científicas y otros actores clave. No se identificaron otros comparadores relevantes para la evaluación. Población: Hombres y mujeres adultos con enfermedad de Alzheimer. Conclusiones: La evidencia disponible sobre la eficacia de los inhibidores de acetilcolinesterasa (donepezilo, galantamina y rivastigmina) muestra un efecto sobre la cognición y la funcionalidad de los pacientes con enfermedad de Alzheimer moderada y severa. Las comparaciones directas disponibles y las comparaciones indirectas no permiten establecer la superioridad de alguno de los inhibidores de colinesterasa. La eficacia de la memantina para el manejo de la enfermedad de Alzheimer moderada en comparación con rivastigmina no ha sido evaluada en experimentos clínicos controlados. El perfil de seguridad de las intervenciones en estudio es similar al del comprador (rivastigmina).

Efficacy of memantine in acute non-arteritic ischemic optic neuropathy

Evaluation of efficacy of Memantine [N-Methyl-D-Aspartate Receptor Antagonist] on visual function of patients with acute non-arteritic ischemic optic neuropathy [NAION]. The study was conducted as interventional case series from November 2005 through November 2006 in Farabi Eye Hospital. Twenty-two patients with acute NAION of less than 8 weeks duration entered the study. Memantine was prescribed with a dose of 5 mg per day for the first week and 10 mg per day for the following two weeks. Baseline best corrected visual acuity [BCVA]; visual evoked potential [VEP] and visual field was done for all patients. BCVA recording repeated 3 weeks, 3 and 6 months later. VEP and perimetry repeated 3 months after treatment. After 3 weeks, 3 and 6 months, BCVA improved -0.32 +/- 0.40 LogMAR, -0.51 +/- 0.49 and -0.51 +/- 0.49, respectively [P=0.005, P=0.001 and P=0.001, respectively]. VEP recordings after 3 months, demonstrated -8.61 +/- 14.51 db mean decrease in implicit time [P=0.019]. Amplitude of voltage did not show significant difference with baseline [P=0.10]. Perimetry results after 3 months showed that mean deviation [MD] improved 2.77 +/- 3.94 db [P=0.016]. Memantine resulted in significant improvement of BCVA 3 weeks, 3 and 6 months after treatment of acute NAION. Memantine also resulted in significant decrease of implicit time and significant improvement of mean deviation in VEP and perimetry after 3 months

Memantine: pharmacological properties and clinical uses.

Memantine is a relatively new drug specially developed for use in moderate-to-severe dementia. It is an uncompetitive N-methyl-D-aspartate receptor antagonist and reduces glutamatergic excitotoxicity. Though Alzheimer's disease (AD) is the commonest cause of dementia in the world, there is no "cure" available for the same. Cholinesterase inhibitors such as donepezil and rivastigmine have been shown to provide symptomatic relief in patients with AD but have no effect on disease progression or survival. Moreover, they are not helpful in more severe stages of dementia. Memantine has been shown to cause modest improvement in clinical symptoms in severe stages of AD and may retard the disease progression. Moreover, it has been shown to be useful in various forms of dementia including AD, vascular dementia and Wernicke-Korsakoff psychosis. It is also the first drug to cause complete disappearance of pendular nystagmus due to multiple sclerosis. The current review focuses on the pharmacological properties of memantine and examines the recent evidence in favor of memantine.