Reacciones adversas a medicamentos de pronóstico grave en ancianos institucionalizados

Resumen

Objetivo

Estudiar las reacciones adversas a medicamentos (RAM) de pronóstico grave en ancianos institucionalizados.

Metodología

Se realizó un estudio epidemiológico prospectivo durante 12 meses recogiendo, de historias clínicas elegidas al azar de ancianos institucionalizados en 5 residencias de Granada y su área metropolitana, información relativa a edad, sexo, número y tipo de medicamentos, diagnóstico y grado de validez fisicopsíquica de los ancianos, RAM con el fármaco imputado y su pronóstico. Como pruebas estadísticas se usaron la de Wilcoxon para variables numéricas y la de Fisher para las cualitativas, y se empleó para el análisis el paquete estadístico STATA versión 7.0.

Resultados

En las 400 historias clínicas consultadas se detectaron 75 RAM, de las que un 33% fueron graves. Los fármacos más implicados fueron los antiinflamatorios no esteroideos (AINE), antidiabéticos y digoxina. Cuatro ancianos requirieron hospitalización por causa de una RAM grave consistente en dos intoxicaciones digitálicas y dos hemorragias digestivas por AINE. No hallamos diferencias estadísticamente significativas entre RAM graves y edad, sexo, número de diagnósticos o grado de validez fisicopsíquica de los ancianos; en cambio, sí hallamos una débil asociación con el número de medicamentos (p = 0,061). El 88% de las RAM graves fueron del tipo A, dependientes de la dosis y previsibles.

Conclusiones

Los ancianos institucionalizados sufren RAM graves en una elevada proporción por AINE, antidiabéticos y digoxina, y en su mayoría son evitables. Destacamos el interés de este tipo de trabajos.

Abstract

Objective

To investigate adverse drug reactions (ADR) with a serious prognosis in institutionalized older persons.

Methodology

This prospective epidemiological study covered a 12-month period (January-December, 2001) during which we collected information from randomly selected medical records of elderly persons living in five nursing homes in Granada, Spain. The variables recorded were age, sex, number and type of drugs, diagnosis, physical and cognitive functioning, ADR, medication involved, and prognosis. Wilcoxon’s test was used for numerical variables and Fisher’s test was used for qualitative variables. All statistical analyses were performed with the STATA 7.0. program.

Results

Four hundred medical records were reviewed and 75 ADR were found. Thirty-three percent of the ADR were serious. The medications most frequently involved were non-steroidal anti-inflammatory drugs (NSAIDs) (48%), antidiabetic drugs (16%) and digoxin (12%). Four elderly individuals were hospitalized because of a serious ADR: two due to digoxin-induced cardiac arrhythmia and two due to NSAID-induced digestive tract bleeding. There were no statistically significant differences in serious ADR according to age, sex, diagnoses, or degree of physical disability or cognitive impairment. A weak relationship was found between serious ADR and the number of drugs (p = 0.061). Nearly all (88%) ADR were type A, dose-dependent, and preventable.

Conclusions

Serious adverse drug reactions in elderly persons living in institutions are frequent and are often caused by NSAIDs, antidiabetic drugs and digoxin. Most cases can be prevented. We highlight the importance of this type of study.