Interacciones farmacológicas potenciales entre antihipertensivos y otros medicamentos de uso crónico / Potential drug interactions between antihypertensive drugs and other chronic use drugs

RESUMEN

Objetivo. Determinar en el ámbito de Atención Primaria la frecuencia de las potenciales interacciones farmacológicas de los medicamentos antihipertensivos. Diseño. Estudio observacional transversal. Emplazamiento. Centro de salud de características urbanas. Participantes. Trescientos veintitrés pacientes seleccionados mediante muestreo consecutivo a partir de tarjetas de largo tratamiento. Nivel de confianza del 95 %; precisión ± 5 %; proporción esperada de interacciones del 30 %. Sujetos: pacientes hipertensos que consumen medicación antihipertensiva. Variables: medicación antihipertensiva, otros fármacos de uso crónico y datos sociodemográficos. Para valorar las combinaciones inadecuadas se utilizó la Guía de Interacciones de Fármacos 2002 de la Sociedad Española de Farmacia Hospitalaria. Análisis de datos: descripción de variables, pruebas de comparación de medias y proporciones en grupos independientes. Mediciones principales. Consumo de antihipertensivos, medicación concomitante, presencia de interacciones según las fichas técnicas de la Sociedad Española de Farmacia Hospitalaria y variables sociodemográficas. Resultados. Edad media de 64,33 años ± 12,24 DE (rango: 32-97), porcentaje de mujeres del 57 %. Número medio de otros medicamentos 3,56 ± 1,45 DE. La distribución con porcentajes de medicamentos antihipertensivos fue: calcioantagonistas: 29 (13,2 %); inhibidores de la enzima conversora de la angiotensina: 225 (70 %); antagonistas del receptor de la angiotensina II: 47 (19,6%); betabloqueantes: 24 (7,2%); alfabloqueantes: 47 (14,6%); alfa-betabloqueantes: 4 (1,2%), y diuréticos: 75 (38,7%). Presentaron alguna interacción moderada o grave el 19,5 % de los pacientes (IC 95 %: 15,2-23,8). Las principales interacciones fueron: enalapril y diuréticos ahorradores de potasio: 8 (2,4 %); captopril y ácido acetilsalicílico: 7 (2,2%); captopril y alopurinol: 3 (0,9 %); nifedipino y omeprazol: 4 (1,2%); nifedipino y antidiabéticos orales: 2 (0,6 %); verapamil y calcio: 2 (0,6 %); doxazosina y diuréticos: 11 (3,4 %); doxazosina y digoxina: 1 (0,3 %); inhibidores de la enzima conversora de la angiotensina o antagonistas del receptor de la angiotensina II y diuréticos como enalapril y tiacidas: 20 (6,2%). La proporción de interacciones no fue significativamente diferente en ambos sexos y tampoco la edad media fue diferente desde el punto de vista estadístico en los pacientes con o sin alguna interacción. Conclusiones. Es elevada la proporción de pacientes consumidores de medicación antihipertensiva que presentan interacciones moderadas o graves, especialmente en el caso del enalapril, captopril, nifedipino, verapamil y doxazosina. Determinadas interacciones pueden ser la causa de un mal control de las cifras tensionales o descompensación de otras patologías. Frente al riesgo potencial de las interacciones de los medicamentos antihipertensivos el médico de Atención Primaria debe considerar, cada vez más por su mayor utilización, la compatibilidad de los mismos con el resto de los fármacos

ABSTRACT

Objective. To determine the frequency of potential drug interactions of antihypertensive drugs in the Primary Health Care Setting. Design. Cross-sectional observational study. Site. Urban health care center. Participants. 323 patients selected by consecutive sampling from long treatment cards. 95 % confidence interval. Accuracy ± 5 %. Expected proportion of interactions 30 %. Subjects: hypertensive patients who take antihypertensive drugs. Endpoints: antihypertensive drugs, other chronic use drugs, and sociodemographic data. To assess inadequate combinations, the 2002 Drug Interactions Guide of the Spanish Society of Hospital Drugs was used. Data analysis: description of endpoints, mean comparison tests and proportions in independent groups. Main measurements. Use of antihypertensive drugs, concomitant medications, presence of interactions according to Spanish Society of Hospital Drug data sheets and sociodemographic endpoints. Results. Mean age of 64.33 years ± 12.24 SD (range: 32-97), percentage of women 57 %. Mean number of other drugs 3.56 ± 1.45 SD. Distribution with percentages of antihypertensive drugs was: calcium antagonists: 29 (13.2 %); ACEIs: 225 (70 %); ARA II: 47 (19.6 %); beta blockers: 24 (7.2 %); alpha blockers: 47 (14.6%); alpha-beta blockers: 4 (1.2 %) and diuretics: 75 (38.7%). A total of 19.5 % of the patients had some moderate or serious interaction (95 % CI: 15.2-23.8). The main interactions were: enalapril and potassium saving diuretics: 8 (2.4 %); captopril and ASA: 7 (2.2%); captopril and allopurinol: 3 (0.9 %); nifedipine and omeprazole: 4 (1.2 %); nifedipine and oral antidiabetics: 2 (0.6 %); verapamil and calcium 2 (0.6 %); doxazosine and diuretics: 11 (3.4%); doxazosine and digoxine 1 (0.3 %), ACEI or ARA II and diuretics as enalapril and thiazides: 20 (6.2 %). The proportion of interactions was not significantly different in both genders and the mean age was also not different from the statistical point of view in patients with or without some interaction. Conclusions. The percentage of patients using antihypertensive drugs who have moderate or serious interactions is high, especially in the case of enalapril, captopril, nifedipine, verapamil and doxazosine. Certain interactions may be the cause of poor control of tension values or decompensation of other diseases. Faced with the potential risk of the interactions of antihypertensive drugs, the Primary Health care physician should increasingly consider the compatibility of these with the remaining drugs due to its greater useObjective. To determine the frequency of potential drug interactions of antihypertensive drugs in the Primary Health Care Setting. Design. Cross-sectional observational study. Site. Urban health care center. Participants. 323 patients selected by consecutive sampling from long treatment cards. 95 % confidence interval. Accuracy ± 5 %. Expected proportion of interactions 30 %. Subjects: hypertensive patients who take antihypertensive drugs. Endpoints: antihypertensive drugs, other chronic use drugs, and sociodemographic data. To assess inadequate combinations, the 2002 Drug Interactions Guide of the Spanish Society of Hospital Drugs was used. Data analysis: description of endpoints, mean comparison tests and proportions in independent groups. Main measurements. Use of antihypertensive drugs, concomitant medications, presence of interactions according to Spanish Society of Hospital Drug data sheets and sociodemographic endpoints. Results. Mean age of 64.33 years ± 12.24 SD (range: 32-97), percentage of women 57 %. Mean number of other drugs 3.56 ± 1.45 SD. Distribution with percentages of antihypertensive drugs was: calcium antagonists: 29 (13.2 %); ACEIs: 225 (70 %); ARA II: 47 (19.6 %); beta blockers: 24 (7.2 %); alpha blockers: 47 (14.6%); alpha-beta blockers: 4 (1.2 %) and diuretics: 75 (38.7%). A total of 19.5 % of the patients had some moderate or serious interaction (95 % CI: 15.2-23.8). The main interactions were: enalapril and potassium saving diuretics: 8 (2.4 %); captopril and ASA: 7 (2.2%); captopril and allopurinol: 3 (0.9 %); nifedipine and omeprazole: 4 (1.2 %); nifedipine and oral antidiabetics: 2 (0.6 %); verapamil and calcium 2 (0.6 %); doxazosine and diuretics: 11 (3.4%); doxazosine and digoxine 1 (0.3 %), ACEI or ARA II and diuretics as enalapril and thiazides: 20 (6.2 %). The proportion of interactions was not significantly different in both genders and the mean age was also not different from the statistical point of view in patients with or without some interaction. Conclusions. The percentage of patients using antihypertensive drugs who have moderate or serious interactions is high, especially in the case of enalapril, captopril, nifedipine, verapamil and doxazosine. Certain interactions may be the cause of poor control of tension values or decompensation of other diseases. Faced with the potential risk of the interactions of antihypertensive drugs, the Primary Health care physician should increasingly consider the compatibility of these with the remaining drugs due to its greater use