Methylparaben concentration in commercial Brazilian local anesthetics solutions

OBJECTIVE: To detect the presence and concentration of methylparaben in cartridges of commercial Brazilian local anesthetics. MATERIAL AND METHODS: Twelve commercial brands (4 in glass and 8 in plastic cartridges) of local anesthetic solutions for use in dentistry were purchased from the Brazilian market and analyzed. Different lots of the commercial brands were obtained in different Brazilian cities (Piracicaba, Campinas and São Paulo). Separation was performed using high performance liquid chromatography (HPLC) with UV-Vis detector. The mobile phase used was acetonitrile:water (75:25 - v/v), pH 4.5, adjusted with acetic acid at a flow rate of 1.0 ml.min-1. RESULTS: When detected in the solutions, the methylparaben concentration ranged from 0.01% (m/v) to 0.16% (m/v). One glass and all plastic cartridges presented methylparaben. CONCLUSION: 1. Methylparaben concentration varied among solutions from different manufacturers, and it was not indicated in the drug package inserts; 2. Since the presence of methylparaben in dental anesthetics is not regulated by the Brazilian National Health Surveillance Agency (ANVISA) and this substance could cause allergic reactions, it is important to alert dentists about its possible presence.

Is palatal injection mandatory prior to extraction of permanent maxillary tooth: A preliminary study.

Introduction: Even after the invention of the modern injection techniques, palatal injection still remains a painful experience for patients, and this pain is attributed to the presence of rich nerve complement and displacement of palatal mucosa during anesthesia. Objective: The aim of the present study was to demonstrate if lidocaine HCl could provide palatal anesthesia if given buccally during maxillary tooth removal without the need for a palatal injection. Materials and Methods: The study group consisted of 75 patients, and 25 were controls. All the patients in the study group had unilateral extractions. In 75 patients, 2 ml of 2% lidocaine HCl with 1:80,000 epinephrine was injected into the buccal vestibule of tooth indicated for extraction without palatal injection. After 8 min, the extraction of maxillary tooth was carried out. Twenty-five subjects in the control group underwent same protocol with palatal injection. All the patients completed a faces pain scale (FPS) and a 100 mm visual analog scale (VAS) after extraction. Statistical Analysis Used: Unpaired t test and Chi-square test. Results: According to VAS and FPS scores, when comparison was carried out between permanent maxillary tooth removal with and without palatal injection, the difference in the pain levels were not statistically significant (P>0.05). Conclusion: The extraction of permanent maxillary tooth is possible by depositing 2 mL of lidocaine to the buccal vestibule of the tooth without the need for palatal anesthesia.

Efeitos hemodinâmicos da intoxicação aguda com bupivacaína e a mistura enantiomérica: estudo experimental em suínos / Haemodynamic effects of intoxication with bupivacaine and enantiomeric excess mixture: experimental study in swine

OBJETIVOS: A bupivacaína racêmica tem sido o anestésico local de escolha nos bloqueios regionais pela qualidade e duração de sua anestesia. Sua cardiotoxicidade é motivo de preocupações, e pesquisas têm sido realizadas para encontrar drogas com menor impacto. Seu isômero levógiro, a levobupivacaína, seria menos cardiotóxico pela menor afinidade aos receptores dos canais de sódio do coração, e é uma opção. Em nosso país, uma apresentação contendo 75 por cento do isômero levógiro e 25 por cento do isômero dextrógiro, denominada mistura enantiomérica, está disponível. O objetivo deste estudo foi comparar as repercussões hemodinâmicas da injeção intravascular de uma dose tóxica destes dois agentes em suínos. MÉTODOS: Suínos da raça Large White foram anestesiados com tiopental, entubados e ventilados mecanicamente, sendo, em seguida, instalada monitorização hemodinâmica com pressão invasiva e cateter de Swan-Ganz numa artéria pulmonar. Após repouso de 30 minutos, os animais foram divididos aleatoriamente em dois grupos, e foi realizada em duplo-cego intoxicação com um dos agentes na dose de 4 mg/kg. Os resultados hemodinâmicos foram avaliados então a um minuto, aos cinco, 10, 15, 20 e 30 minutos. RESULTADOS: A mistura enantiomérica causou maiores repercussões hemodinâmicas do que a bupivacaína racêmica. Estes resultados se opõem aos encontrados em humanos com o isômero levógiro, mas estão de acordo com achados recentes em animais. Extrapolar resultados de animais para seres humanos requer cautela, e novas pesquisas são necessárias. CONCLUSÃO: Em suínos, a mistura enantiomérica mostrou-se mais tóxica do que a bupivacaína racêmica, quando grandes doses são injetadas por via endovenosa.

BACKGROUND: Racemic bupivacaine has been the local anaesthetic of choice in regional blocks due to quality and duration of anesthesia. However its cardiovascular toxicity has been a source of concern and research has been made for lesser impact drugs. One choice is its levogyre isomer, levobupivacaine, apparently less cardiotoxic due a lower affinity to the heart sodium channels. In Brazil, a drug containing 75 percent of levogyre isomer and 25 percent of dextrogyre isomer, called enantiomeric excess mixture, is available. This study intends to evaluate haemodynamic effects of the intravascular injection of a toxic dose of both agents in swine. METHODS: Large White pigs were anaesthetized with thiopental, intubated and placed on mechanical ventilation. Haemodynamic monitoring was performed with an invasive blood pressure and Swan-Ganz catheter on a pulmonary artery. After a 30 minute rest period, animals were randomly divided in two groups and the intoxication was performed on a double-blind method with 4 mg.kg-1 of one of the drugs. Haemodynamic parameters were then evaluated at 1, 5, 10, 15, 20 and 30 minutes. RESULTS: The enantiomeric excess mixture caused greater haemodynamic effects than the racemic bupivacaine. These results diverge from those found in humans with levogyre isomer but are similar to recent results reported in animals. Care should be taken when extrapolating data obtained in swine to humans and further research is necessary. CONCLUSION: When high doses are injected in swine, the enantiomeric excess mixture was more toxic than the racemic bupivacaine.

Guía de práctica clínica basada en la evidencia para el manejo de la paciente embarazada que requiera tratamiento endodóntico / Evidence-based clinical practice guide for the management of the pregnant patients requiring endodontic treatment

Antecedentes: el tratamiento odontológico de los pacientes sistémicamente comprometidos tiene cada vez más importancia en el campo de la salud bucal. El sistema general de seguridad social actual en Colombia crea la necesidad de establecer protocolos para el diagnóstico y tratamiento de las diferentes patologías, con evidencia científica para el mejoramiento en la calidad de la atención de los usuarios. La mayoría de los protocolos que existen actualmente para el manejo del paciente con compromiso sistémico y diangóstico de patología bucal, se presentan como revisiones teóricas con poca aplicabilidad clínica o con una inapropiada sustentación científica; de igual forma, se encuentra diversidad de procedimientos terapéuticos para abordar una mismma patología, generando serias dificultades para unificar criterios de planes de tratamiento en este grupo de pacientes. Objetivo: diseñar guías de práctica clínica bassadas en la evidencia para el manejo del paciente sistémicamente comprometido que requiera tratamiento. En este artículo se presenta una revisión que concierne a la condición sistémica del embarazo. Métodos: revisión sistemática de la literatura y desarrollo de guías de práctica clínica con metodología de medicina basada en la evidencia. Resultados: desarrollo de la guía de práctica clínica basada en la evidencia para el manejo de la paciente embarazada que requiera tratamiento endodóntico. Conclusiones: la realización de esta guía ofrece una ilustración práctica de los puntos críticos de la toma de decisiones para el tratamiento endodóntico de la paciente embarazada (uso de anestésicos, analgésicos, antibióticos y toma de radiografías) y garantiza que éstas sean tan realizables y éticas como sea posible

Cambios en la presión sanguínea y frecuencia del pulso durante la extracción dental en aborígenes Tobas / Changes in blood pressure and pulse rate during dental extraction in Toba aborigines

El objetivo de este estudio fue investigar los cambios en la presión sanguínea y frecuencia del pulso durante la extraccion dental en una comunidad aborigen Argentina. Un total de 40 pacientes normotensos fueron agrupados de acuerdo al tipo de tratamiento dental: grupo test (exodoncia), n=20, edad media = 34 14; grupo control (tratamiento restaurativo), n=20, edad media = 27 14. La frecuencia del pulso, la presión sistólica y diastólica fueron registradas en diferentes tiempos, antes, durante y al final del tratamiento. En todos los sujetos, el anestésico local utilizado fue carticaína al 4 por ciento con adrenalina 1:100.000. La Escala de Ansiedad Dental de Corah (EAD) fue aplicada en todos los casos con la finalidad de deterinar la relación entre la ansiedad dental y la respuesta cardiovascular. La presión sanguínea y la frecuencia del pulso se incrementaron significativamente durante la extracción dental (p < 0.01) y estos cambios estuvieron positiva y altamente correlacionados con la puntuación de la EAD. En contraste, la frecuencia del pulso y la presión sanguínea no cambiaron significativamente durante el tratamiento restaurativo, y la correlación con la puntuación de la EAD fue moderada. Estos resultados indican el efecto que la extracción dental puede tener sobre el sistema cardiovascular y la importancia de minimizar la ansiedad dental en este grupo aborigen

Levobupivacaína, anestésico local de acción prolongada, con menor cardio y neurotoxicidad / Levobupivacaine, local anesthesic with less cardiotoxic and less neurotoxic complications

La levobupivacaina es el isomero levogiro de la mezcla racemica de bupivacaina. Estudios en animales y en seres humanos demuestran que esta molécula es menos cardiotóxica y menos neurotóxica. En este articulo se hace una revision de aspectos quimicos, farmacocineticos, farmacodinamicos, toxicológicos y clinicos de la levobupivacaina

Molecular and physicochemical aspects of local anesthetic-membrane interaction

Local anesthesia is achieved by the binding of anesthetic molecules to the sodium channel, a membrane protein responsible for the transport of the extracellular sodium to the cytosol. Local anesthetics (LA) bind to the sodium channel inhibiting sodium transport and, as a consequence, the action potential responsible for the nervous impulse. Most LA are relatively hydrophobic ionizable amines that undergo partitioning into lipid. Both activity and toxicity correlate positively with LA hydrophobicity. Effects of LA on the structural and dynamical properties of the membranes lipid region may be responsible for some of the toxic effects caused by these molecules. The present review focuses on research done on the interaction between both the charged and uncharged forms of LA and lipid systems - bilayers and micelles. LA have been found to alter phospholipid gel to liquid crystal phase transition temperature (Tc), to affect bilayer permeability, to influence molecular packing, and to inhibit the bilayer to hexagonal phase transition. Anesthetics in micellized form disrupt bilayers giving rise to lipid-LA mixed micelle-like aggregates. The question of LA location in the bilayer is also addressed. Special emphasis is placed on work focusing on the quantitative analysis of drug binding, as well as on the effects of binding on physicochemical properties of the LA, such as extent of ionization (pK shifts) and rates of chemical reactions. The understanding of these phenomena has contributed to the development of less toxic liposomal formulations capable of prolonging the duration of anesthesia.