RESUMEN
BACKGROUND: Benzodiazepines have a direct bronchodilatory effect. Methacholine is a non-selective muscarinic receptor agonist causing bronchoconstriction. AIM: To examine the effects of inhaled benzodiazepines, modulating bronchoconstriction induced by methacholine in patients with asthma. PATIENTS AND METHODS: Twelve patients with well controlled asthma were studied. On the first day, after determining the initial values of pulmonary function, a dose response curve was carried out with progressive doses of methacholine. After the last dose, when at least a 20% drop of the initial forced expiratory volume in the first second (FEV1) was achieved, vital capacity (VC) and FEV1 were measured at 7, 15 and 30 minutes after provocation. On the second day a diazepam aerosol was inhaled by the patients prior to the same protocol with methacholine. RESULTS: In the first day of testing, methacholine inhalation (6 mg/mL) led to a significant drop in FEV1 from 2.98 to 1.69 L. On the second day of study, in the same patients, previous inhalation with diazepam reduced the changes of FEV1 after inhalation of methacholine. This parameter decreased from 2.48 to 2.21 L. CONCLUSIONS: Inhalation of benzodiazepines reduce bronchoconstriction after a methacholine challenge in patients with asthma.
Asunto(s)
Asma/prevención & control , Broncoconstricción/efectos de los fármacos , Broncoconstrictores/antagonistas & inhibidores , Diazepam/farmacología , Cloruro de Metacolina/antagonistas & inhibidores , Receptores de GABA-A/uso terapéutico , Administración por Inhalación , Adulto , Antropometría , Asma/fisiopatología , Benzodiazepinas/uso terapéutico , Pruebas de Provocación Bronquial/métodos , Relación Dosis-Respuesta a Droga , Femenino , Volumen Espiratorio Forzado/efectos de los fármacos , Volumen Espiratorio Forzado/fisiología , Humanos , Masculino , Persona de Mediana Edad , Valores de Referencia , Reproducibilidad de los Resultados , Factores de Tiempo , Capacidad Vital/fisiologíaRESUMEN
Background: Benzodiazepines have a direct bronchodilatory effect. Methacholine is a non-selective muscarinic receptor agonist causing bronchoconstriction. Aim: To examine the effects of inhaled benzodiazepines, modulating bronchoconstriction induced by methacholine in patients with asthma. Patients and Methods: Twelve patients with well controlled asthma were studied. On the first day, after determining the initial values of pulmonary function, a dose response curve was carried out with progressive doses of methacholine. After the last dose, when at least a 20% drop of the initial forced expiratory volume in the first second (FEV1) was achieved, vital capacity (VC) and FEV1 were measured at 7, 15 and 30 minutes after provocation. On the second day a diazepam aerosol was inhaled by the patients prior to the same protocol with methacholine. Results: In the first day of testing, methacholine inhalation (6 mg/mL) led to a significant drop in FEV1 from 2.98 to 1.69 L. On the second day of study, in the same patients, previous inhalation with diazepam reduced the changes of FEV1 after inhalation of methacholine. This parameter decreased from 2.48 to 2.21 L. Conclusions: Inhalation of benzodiazepines reduce bronchoconstriction after a methacholine challenge in patients with asthma.
Antecedentes: Las benzodiacepinas tienen un efecto broncodilatador directo. La metacolina es un agonista muscarínico que causa bronco constricción. Objetivo: Evaluar el efecto modulador de la inhalación de diazepam sobre la bronco constricción inducida por metacolina. Pacientes y Métodos: Se estudiaron 12 pacientes con asma bien controlada. En el primer día, se determinó la curva dosis respuesta de parámetros de función pulmonar a una dosis progresiva de metacolina. Después de la última dosis, cuando se consiguió un 20% de reducción en la capacidad vital forzada en el primer segundo (FEV1), se midió FEV1 y la capacidad vital (CV) a los 7, 15 y 30 min después de la provocación. En el segundo día los pacientes se inhalaron con diazepam antes de hacer la prueba con metacolina. Resultados: En el primer día, el FEV1 bajo de 2,98 a 1,69 l con 6 mg/ml de metacolina. En el segundo día, la inhalación de diazepam redujo la respuesta a metacolina con una reducción de FEV1 de 2,48 a 2,21 L. Conclusiones: La benzodiacepinas reducen la respuesta de vasoconstricción a metacolina.