Fundamento: Determinar el porcentaje de pacientes adherentes a los fármacos antirretrovirales, mediante recuento de comprimidos y concentraciones de fármacos. Establecer las variables que se relacionan con una mala adherencia. Pacientes y método: Estudio observacional y prospectivo de una muestra de 202 pacientes, en tratamiento antirretroviral, seguidos durante 9 meses. Durante el período de seguimiento se practicó recuento de los comprimidos dispensados y se realizaron determinaciones trimestrales de los valores séricos de los fármacos. Al inicio y al final del seguimiento se realizaron un cuestionario estructurado y una revisión de las historias clínicas. Se consideró a un paciente como no adherente si la media del recuento de comprimidos fue inferior al 90% o alguna de las determinaciones de fármacos era inferior al nivel umbral establecido. Resultados: El porcentaje de pacientes no adherentes fue del 41,2%. En el análisis univariante, los pacientes no adherentes eran más jóvenes, de sexo femenino, en programa de mantenimiento con metadona (PMM), con puntuaciones más elevadas en el test de Beck Depression Inventory, requiriendo más frecuentemente tratamiento psiquiátrico, presentaron con más frecuencia efectos secundarios y habían realizado previamente interrupciones voluntarias del tratamiento. Los pacientes con relaciones homosexuales presentaron una mejor adherencia. En el análisis multivariante las variables que mejor explicaron la no adherencia fueron: pertenecer al sexo femenino (odds ratio [OR] = 2,6 [1,04-6,65], estar en PMM (OR = 9,43 [1,01-88]), presentar efectos secundarios (OR = 2,63 [1,09-6,33]) y tener antecedentes de interrupciones voluntarias del tratamiento (1,09-6,36). Conclusiones: El porcentaje de pacientes adherentes a los tratamientos antirretrovirales (58,8%) no difiere del observado en otras enfermedades crónicas. Los factores sociodemográficos (sexo femenino, bajo nivel de estudios), estar en PMM o con consumo activo de tóxicos y tener problemas psiquiátricos, principalmente depresión, parecen determinantes en la adherencia a estos fármacos.
Background. We aimed at measuring the adherence to HAART by means of pill count and drug plasma levels. In addition, we aimed at determining variables associated with suboptimal adherence. Patients and method: Prospective observational study of 202 consecutive patients with HIV infection who were receiving antiretroviral treatment, followed up during 9 months. At baseline and at the end of the study a structured questionnaire was administered and a review of medical charts was performed. The adherence was assesed by monthly pill count while drug plasma levels were measured every three months. We considered that a patient adherence was not fulfilled when the mean pill count was < 90% or when any plasma drug level was lower than that expected. Results: Of 143 available patients, 41.2% were non-adherent. According to the univariate analysis, non-adherent patients were more likely to be younger, female, under a methadone maintenance scheme, under psychiatric treatment, to have depression (according to the Beck Depression Inventory), to have adverse antiretroviral effects and to have a previous history of voluntary withdrawal of the treatment. Men who had sex with other men were significantly more adherent. In the multivariate analysis, female sex [OR 2.6 (1.04-6.65)], to be under a methadone program [OR 9.43 (1.01-88)], to have adverse drug effects [OR 2.63 (1.09-6.33)] and to have a previous history of voluntary withdrawal [OR 2.63 (1.09-6.36)] were independent risk factors for non-adherence. Conclusions: Adherence to antiretroviral therapy was 58.8%, similar to that seen in other chronic diseases. To be under a methadone maintenance program and having an active drug addiction was related with non-adherence. Women with worst adherence levels had frequently psychiatric comorbidity and more adverse drug effects.