Notas de farmacología: estudios de disolución de medicamentos del sistema nervioso central / Pharmacology notes: drug dissolution studies of the central nervous system

El propósito de los estudios in vitro es comparar las características de liberación del principio activo contenido en una forma farmacéutica sólida oral mediante la cantidad, o porcentaje de la dosis, disuelta en función del tiempo en condiciones controladas y validadas. Se realizó una comparación de disolución in vitro de flunitrazepam (Rohypnol®, Somnidual® e Inervon®) y de lamotrigina (Lamictal® y Epilepax®). Para los perfiles de disolución de flunitrazepam, una de las marcas comerciales tuvo un perfil de disolución muy diferente a las otras dos marcas. Para el caso de lamotriginano existió diferencia para aquellos pH que se consideran fundamentales para la disolución del comprimido en el tracto gastrointestinal. Los resultados obtenidos de los estudios in vitro son simplemente orientadores, permiten tan solo guiar la puesta en marcha del ensayo de bioequivalencia entre el test evaluado in vitro y la referencia utilizada en el mismo ensayo. No obstante, estos resultados pueden constituirse en un elemento de apoyo a la presunción de bioinequivalencia como causa de un evento adverso (ineficacia o toxicidad) detectado en los programas de farmacovigilancia actualmente en marcha.

Single—dose subcutaneous administration of flunitrazepam for insomnia in patients with advanced cancer

Insomnia in advanced cancer patients has a highly negative impact on the patients, their families and caregivers. Insomnia is principally managed by pharmacological therapy； however, most advanced cancer patients are unable to receive oral medications. This prospective audit study investigated the efficacy of single—dose subcutaneous administration of flunitrazepam for treating insomnia in patients with advanced cancer. Sleep evaluation was conducted using the St. Mary’s Hospital Sleep Questionnaire. The primary endpoint was the quality of sleep； the secondary endpoints comprised other subscales of total sleep time, sleep latency and adverse effects. We enrolled 30 patients. The average dose of flunitrazepam dose was 0.9(0.1)mg. The good response rate for the quality of sleep was 90％. The total sleep time and sleep latency were 7.5(3.2)h and 31(9.1)min, respectively. Two patients were newly diagnosed with delirium during the study. The mean respiratory rate decreased(15/min before treatment to 14/min after treatment, P＝0.01) without any critical events. Single—dose subcutaneous administration of flunitrazepam may be potentially efficacious and simple in treating insomnia in advanced cancer patients.

Evaluation of cytotoxicity and mutagenicity of the benzodiazepine flunitrazepam in vitro and in vivo

Flunitrazepam (FNZ) is a sedative benzodiazepine prescribed for the short-term treatment of insomnia. However, there are concerns regarding possible carcinogenic or genotoxic effects of this medicine. Thus, the aim of this study was to evaluate the cytotoxic, clastogenic and aneugenic effects of FNZ in hepatoma cells from Rattus norvegicus (HTC) in vitro and in bone marrow cells of Wistar rats in vivo. These effects were examined in vitro following treatment with 0.2, 1.0, 5.0 or 10 μg/mL FNZ using a micronucleus test with a cytokinesis block or in vivo using a chromosomal aberration test following treatment with 7, 15 or 30 μg/mL/kg body weight. The results showed that the benzodiazepine concentrations tested were not cytotoxic, aneugenic or clastogenic. However, considering the adverse effects of using this benzodiazepine, more studies are required.

Flunitrazepam (FNZ) é um sedativo benzodiazepínico prescrito para o tratamento da insônia em curto prazo. Entretanto, existe a preocupação com relação aos possíveis efeitos carcinogênicos ou genotóxicos causados por este fármaco. Então, o objetivo deste estudo foi avaliar os efeitos citotóxicos, clastogênicos e aneugênicos do FNZ em células de hepatoma de Rattus norvegicus (HTC) in vitro e em células de medula óssea de ratos Wistar in vivo. Foram testadas as concentrações de 0,2, 1,0 e 10 μg/mL de FNZ pelo teste do micronúcleo com bloqueio de citocinese in vitro e 7, 15 e 30 μg/mL/kg de peso corpóreo para o teste de aberração cromossômica in vivo. Os resultados mostraram que as concentrações do benzodiazepínico testadas não foram citotóxicas, aneugênicas ou clastogênicas. Entretanto, considerando os efeitos adversos do uso deste benzodiazepínico, mais estudos são necessários.

Correlation between function-morphology of effect of the stress and flunitrazepam administered during gestation in adult mouse ovary / Correlación entre la función y la morfología de los efectos de estrés y flunitrazepam administrado durante la gestación en ovario de ratón adulto

Previously we report long lasting effects on ovary of mice prenatally exposed to flunitrazepam (FNZ), a benzodiazepine with tranquilized action. In this work we find that the FNZ don't prevent the effects on ovary prenatally exposure to stress in mice. We studied adult females born from mothers that had been stressed by immobilization on day 6 ofgestation (GD-6) or group S, and from mothers stressed also by immobilization at GD-6, but which received a single oral dose of FNZ immediately after the stress group FNZS. The control groups were the SS that received the GD-6 saline solution and the group NT non-treated. Their ovaries were extracted for histology studies and to observe the activity of 3b hydroxysteroid dehydrogenase/isomerase (3 b-HSD). The histological analysis revealed high staining affinity ovarian cell of S and FNZS. Double oocytes and apoptotic bodies were found in the secondary atretic follicles, as well as abnormal primordial, primary and secondary follicle populations, as compared to SS and NT groups. The primordial, primary, and secondary follicles were significantly reduced in the experimental groups. But the primary and secondary atretic follicles were higher in both groups, and the number of corpora lutea was lower in both groups. The activity of 3 b-HSD was abnormally increased in both FNZS- and S-groups. These findings suggest that FNZ did not counteract the impairing effects of prenatal stress on adult offspring ovarian follicles, and could rather be responsible for long lasting changes occurring during embryonic programming.

Previamente comprobamos efectos de larga duración sobre el ovario de ratones expuestos prenatalmente a flunitrazepam (FNZ), una benzodiazepina con acción tranquilizante. En este trabajo encontramos que el FNZ, no revierte los efectos producidos por la exposición prenatal a estrés. Estudiamos hembras adultas nacidas de madres que se estresaron por inmovilización el día 6 de la gestación (DG-6) o grupo S, y de madres estresadas también por inmovilización el DG-6, las que recibieron una sola dosis de FNZ inmediatamente después del estrés (grupo FNZS). Los grupos de control fueron el SS al que se le administró solución salina y el NT no tratado. Se extrajeron sus ovarios para su estudio histológico y para observar la actividad de delta 3b-deshidroxiesteroide dehidrogenasa/isomerasa (3 b-HSD). El análisis histológico reveló una gran afinidad tintoreal en los ovarios de los grupos S y FNZS. En los ovarios de los ratones del grupo FNZS se encontraron en los folículos secundarios atrésicos ovocitos dobles y cuerpos apoptóticos así como una población mayor de folículos anormales primordiales, primarios y secundarios en comparación con los grupos SS y NT. Los folículos primarios y secundarios tuvieron una reducción significativa en los grupos experimentales pero los folículos atrésicos primarios y secundarios fueron más en ambos grupos y el número de cuerpos lúteos fue menor en ambos grupos. La actividad de 3 b-HSD aumentó de manera anormal tanto en los grupos FNZ y S. Estos hallazgos sugieren que el FNZ no contrarresta los efectos negativos del estrés prenatal sobre los folículos ováricos de las crías adultas, y podría ser responsable de los cambios largo plazo que ocurren a durante la programación embrionaria.

Histological Changes of the Ovary of Adult Mice Exposed Prenatally to Flunitrazepam / Cambios Histológicos del Ovario de Ratones Adultos Expuestos Prenatalmente a Flunitrazepam

Flunitrazepam (FNZ) is a minor tranquillizer involving allosteric modulation of the GABA receptor complex. It is a ligand of the peripheral benzodiazepine receptor (PBR) that participates in cholesterol transport in steroidogenic organs. The purpose was to investigate whether a single oral dose of FNZ of 2.5 mg/kg of body weight (bw), administered on day 6 of gestation, alters the structure of the adult ovary of mouse offsprings at 2 months of age. The mouse offsprings of the in utero FNZ-treated group and those of the control group (C) were killed. Ovaries were obtained in early estrous, fixed in Zenker solution, and processed by routine histological techniques. Serial sections were observed under light microscopy to determine the characteristics and quantity of follicles in different stages of development and of the corpus luteum. The ovarian tissues from the FNZ group depicted a great staining affinity, enlarged nuclei with abundant heterochromatin clumps. The quantity of primordial, primary and secondary normal follicles in the FNZ group decreased significantly (p< 0.01). The number of primary atretic follicles increased (p<0.01) and the secondary ones remained constant as in group C. Histological changes and statistical data suggest that FNZ produces long-lasting epigenetic or genotoxic effects in follicular and corpus luteum cells of the ovary of prenatally FNZ-treated mice.

El flunitrazepam (FNZ) es un tranquilizante menor que actúa modulando el receptor GABA, es un ligando del receptor benzodiazepínico periférico (PBR), el cual participa en el transporte de colesterol en órganos esteroidogénicos. El objetivo de este trabajo fue investigar si una dosis oral de FNZ (2.5mg/kg de peso) administrada en el sexto día de gestación, altera la estructura del ovario en crías de ratón adultos. Las crías del grupo FNZ tratadas in utero con la benzodiazepina, así como el grupo control, fueron sacrificadas. Los ovarios se extrajeron en estro temprano, se fijaron en líquido de Zenker y procesaron con las técnicas habituales de histología. Los cortes seriados fueron analizados mediante microscopia óptica, los folículos fueron identificados y contados de acuerdo a los diferentes estadios del desarrollo, así como las células del cuerpo lúteo. El tejido ovárico en el grupo de FNZ presentó una gran afinidad tintórea, núcleos grandes y con abundantes cúmulos de heterocromatina. El número de folículos primordiales, primarios y secundarios en el grupo FNZ disminuyó (p<0.01). Contrario al número de folículos atrésicos que aumentaron (p<0.01), a excepción de los folículos atrésicos secundarios que no fueron diferentes a los controles. Las alteraciones histológicas y los datos estadísticos sugieren que el FNZ produce un efecto epigenético o genotóxico de largo plazo tanto en los folículos como en las células del cuerpo lúteo, de ratones tratados prenatalmente con el fármaco.

Emprego do flunitrazepam na sedação de suínos / Use of flunitrazepam for sedation of swines

Na presente pesquisa avaliou-se o flunitrazepam, em diferentes doses, na tranqüilização de 24 suínos da raça Landrace. Os animais foram divididos em 4 grupos onde, após jejum prévio, anotou-se os parâmetros basais (M0) de frequência cardíaca, respiratória, temperatura retal e hemogasimetria arterial. Ato contínuo, administrou-se o flunitrazepam nas doses de 0,01; 0,02 e 0,03mg/kg, intramuscular (IM), aos grupos I, II e III, respectivamente. O grupo IV (controle) recebeu igual volume de solução fisiológica por via IM. Os dados paramétricos e de hemogasimetria foram coletados a intervalos de 10 minutos após a administração da droga, durante o período de uma hora. Concomitantemente efetuaram-se observações clínicas a respeito do grau de sedação proporcionado pelo flunitrazepam. Não foram verificadas alterações significativas nos parâmetros cardíacos e respiratórios. A dose de 0,03 mg/kg produziu o maior grau de sedação sem interferir significativamente com os parâmetros hemogasimétricos.

In this research, it was evaluated the flunitrazepam, at different doses, in the tranquilization of 24 landrace swines. The animais were distributed into 4 groups and, after a previous fasting, the cardiac and respiratory rates were recorded as well as the rectal temperature and blood gas analisis. Just after that, the flunitrazepam was injected at dosages of 0.01; 0.02 and 0.03mg/kg IM for the groups I, II and III, respectively. The group IV (control) received the same volume of saline (0.9 percent) intramuscularly. The parametrical and blood gas recordings were performed at 10 minute intervals after the drug administration, over an hour period. At the same time, observations were performed about the clinical efectiveness of the sedation. Significant changes were not observed in cardiac and respiratory rates at different dosages apphed. The dosage of 0.03 mg/kg produced the best level of sedation, without significam changes in the blood gas values.

Emprego da associação flunitrazepam/droperidol na tranqüilização de suínos / Use of flunitrazepam ano droperidol for tranquilization of swines

Na presente pesquisa avaliou-se a associação flunitrazepam/droperidol na tranqüilização/sedação de 12 suínos da raça Landrace. Os animais foram divididos em dois grupos (GI e GII). Nos grupos I e II foram anotadas as frequências cardíaca, respiratória e temperatura retal antes e após a administração do flunitrazepam (0,03 mg/kg IM) associado ao droperidol (0,4mg/kg IM). No grupo II realizaram-se também análises hemogasimétricas. As anotações paramétricas e hemogasimetria arterial foram repetidas durante uma hora após a administração das drogas, com intervalos de 10 minutos. Concomitantemente efetuaram-se observações a respeito da eficácia da tranqüilização. Não ocorreram alterações significativas nos dados paramétricos e equilíbrio ácido-básico. O tempo médio de ação das drogas foi de 60 minutos, com período de latência de 5 minutos. Durante a tranqüilização houve relaxamento muscular, indiferença a estímulos ambientais, perda dos reflexos posturais e manutenção dos reflexos protetores. A análise dos resultados permite indicar a associação flunitrazepam/droperidol na tranqüilização de suínos.

In this research, it was evaluated the flunitrazepam and droperidol for the tranquilization/sedation of 12 Landrace swines. The animals were divided in two groups (GI e GII). In the groups I and II the cardiac and respiratory rates were recorded, as well as the rectal temperature before and after the flunitrazepam (0.03 mg/kg IM) droperidol (0.4mg/kg IM) injection. In the group II, it was also performed, blood gas analisis. The parametrical recordings and blood gas analisis were obtained during 1 hour after the drugs administration, at 10 minutes intervals. At the same time, observations were performed about the effectiveness of the tranquilization. Significant changes did not occur in the parametrical values and acid-basic oquilibrium. The set time of the drugs action was that of 60 minutes, with an onset period of 5 minutes. During the tranquilization it was observed the musele relief, abscence to ambiental stimulus, loss of the postural reflexos, and keeping of the pain reflexos. The analisis of the results enables to indicate the flunitrazepam/droperidol combination for the tranquilization of swines.