Estudio comparativo de la calidad biofarmacéutica de Alprazolam 0, 5 mg comercializadas en el mercado peruano / Comparative study of the biopharmaceutical quality of Alprazolam 0. 5 mg commercialized in the Peruvian market

El Alprazolam pertenece a las benzodiazepinas. Sus efectos se atribuyen a que actúa sobre receptores de membrana específicos, lo cual facilita la acción inhibitoria presináptica y postsináptica del ácido γ-aminobutírico (GABA), especialmente en la formación reticular ascendente. Se utiliza para el tratamiento de los estados de ansiedad, crisis de angustia, ataques de pánico y estrés intenso. Este estudio se realizó para analizar los parámetros comparativos de control de calidad in vitro mediante la evaluación de la variación de peso, friabilidad, dureza, tiempo de desintegración, perfil y eficiencia de disolución entre el medicamento innovador (Xanax®) y multifuentes que son comercializados en el mercado peruano. Para realizarlo, se seleccionaron tabletas de Alprazolam 0,5 mg multifuente de diferentes laboratorios comparándolos con el medicamento innovador y se evaluaron las características fisicoquímicas y biofarmacéuticas. Los ensayos farmacopeicos se evaluaron según lo establecido en la USP 42. Los resultados de las pruebas fisicoquímicas indicaron que las muestras analizadas no tenían diferencia significativa y estaban dentro de lo establecido en la farmacopea, así mismo el perfil y eficiencia de disolución permitieron establecer que el comportamiento biofarmacéutico de las mismas era muy similar para ambos tipos de molécula. Se estableció que las tabletas multifuentes de Alprazolam 0,5 mg de esta investigación son bioequivalentes con el innovador, por lo que permite proponer a la comunidad científica la determinación de la equivalencia biofarmacéutica como elemento de apoyo en la toma de decisiones de compra en el servicio farmacéutico

Alprazolam belongs to benzodiazepines. Its effects are attributed to the fact that it acts on specific membrane receptors, which facilitates the presynaptic and postsynaptic inhibitory action of γ-aminobutyric acid (GABA), especially in the ascending reticular formation. It is used to treat anxiety states, panic attacks, and intense stress. This study was carried out to analyze comparative parameters of in vitro quality control by evaluating the variation in weight, friability, hardness, disintegration time, profile and dissolution efficiency between the innovative drug (Xanax®) and multi-sources tablets that are marketed in the Peruvian market. To perform this, Alprazolam 0.5 mg multi-source tablets were selected from different laboratories comparing them with the innovative medicine and the physicochemical and biopharmaceutical characteristics were evaluated. Pharmacopoeial trials were evaluated as established in USP 42. The results of physicochemical tests indicated that analyzed samples did not have a significant difference and were within the established in the pharmacopoeia, as well as the profile and dissolution efficiency allowed to establish that their biopharmaceutical behavior was very similar for both types of molecules. It was established that Alprazolam 0.5 mg multi-source tablets from this research are bioequivalent with innovator, which makes it possible to propose to scientific community determination of biopharmaceutical equivalency as a support element in decision-making process for purchasing services pharmacist

A comparative evaluation of the effects of oral lorazepam, alprazolam and diazepam on venous admixture.

OBJECTIVE: To compare the effects of oral diazepam, lorazepam and alprazolam premedication on venous admixture. MATERIAL AND METHODS: One hundred fifty patients divided in three groups were included in the study. The venous admixture was determined using the ISO-shunt nomogram. The values obtained 90 minutes after administration of the drugs were compared with the values before the drug administration. The Student's t-test was applied to find out the significance. RESULTS: These were highly significant change in increase in venous admixture (Qs/Qt) in group I patients 90 minutes after premedication as compared to premedication values. There was statistically insignificant difference in venous admixture (Qs/Qt) in group II and group III patients 90 minutes after premedication as compared to premedication values. CONCLUSION: From the present study it can be concluded that 2 mg of oral lorozepam given 90 minutes before surgery to healthy patients have significant effects on venous admixture. However, the effects of alprazolam and diazepam had no significant effect on venous admixture.

Allergy to tartrazine in alprazolam.

Allergy to tartrazine-containing psychotropic medication (especially antidepressants) had been reported. 20 patients of apparent allergy to tartrazine-containing alprazolam brands in 480 patients exposed to the dye are described. Rechallenge with non tartrazine-containing alprazolam brands did not produce the similar allergic reactions.

Alprazolam modifies animal behaviour on elevated plus-maze.

Exposure to elevated plus-maze is known to evoke approach-avoidance conflict behaviour and anxiety related movements in mice. Alprazolam (0.1 to 1 mg/kg, ip) produced dose dependant increase in antianxiety response, 100% first preference to open arm, open arm entries and exploratory behaviour. This effect was not only comparable to diazepam but also sensitive to reversal by flumazenil, a benzodiazepine receptor antagonist. Withdrawal of alprazolam (2 mg/kg/day for 14 days) and diazepam (20 mg/kg/day for 14 days) from chronic treatment produced typical anxiety response in animals. When tested for transfer latency, a parameter for learning and memory, both diazepam and alprazolam interfered with cognitive behaviour. Besides these actions, alprazolam also possesses anti-depressant property which makes it an atypical benzodiazepine for anxiety, panic disorder and endogenous depression.

Alprazolam en el dolor crónico como equivalente depresivo-ansioso / Alprazolam in chronic pain as a deppresive-anxious equivalent

Diez pacientes con dolor crónico severo, sin evidencia aparente de patología orgánica fueron valorados en un estudio abierto con duración de siete semanas. Después de la primera semana con placebo, los pacientes fueron sometidos a manejo con medicación activa (alprazolam) realizándose evaluación semanal de los siguientes parámetros: escala visual análoga (EVA), récord de síntomas principales, escala de ansiedad de Hamilton (EAH), escala de depresión de Hamilton (EDH), escala de impresión global tanto del paciente como del médico, así como signos vitales. Al final del protocolo nueve pacientes fueron evaluables. Un análisis individual mostró respuestas favorables en la EVA, en EAH y en EDH. La dosis promedio efectiva del alprazolam fue de 2.5mg./día. Los efectos colaterales más frecuentes fueron somnolencia y resequedad de boca. Hubo 3 casos de hipotensión sostenida que determinaron la salida del estudio de esos pacientes

Nuevas Benzodiazepinas / New Benzodiazepines

En el último decenio han aparecido en nuestro mercado cuatro benzodiazepinas, ellas podrían representar avances sutiles pero importantes en el tratamiento de los desórdenes de ansiedad y del insomnio. En este trabajo se revisa brevemente la farmacología, la farmacocinética y las características clínicas de este grupo para facilitar su mejor manejo por el médico. Además, se presenta someramente algunas perspectivas futuras.