Exposure of the elderly to potential nephrotoxic drug combinations in Belgium

Purpose To count in the Belgian ambulatory prescription database Pharmanet, the number of elderly people treated with ACE inhibitors (ACEI) and/or angiotensine receptor blockers (ARB) (+/- diuretics +/- beta-blockers) who eventually also received a prescription of non-steroidal anti-inflammatory drugs (NSAID) or spironolactone. Method All prescriptions dispensed in community pharmacies are collected in the Pharmanet database. The data of 2005 were used. Two age groups were studied: 65-79 years (label 1) and 80+ years (label 2). The following chronic treatments (subgroups) were studied: (A) ACEI/ARB; (B) ACEI/ARB + diuretics; (C) ACEI/ARB + spironolactone; (D) ACEI/ARB + beta- blocker + diuretic and (E) ACEI/ARB + beta-blocker + spironolactone. Results In 2005, 7.3% of Belgian population was chronically treated with ACEI/ARB. Twenty-five percent of 65-79 year-old-patients (subgroup A1) and 36.15% of 80+ year-old-patients (subgroup A2) received ACEI/ARB. At least one package of NSAID or spironolactone was prescribed to subgroup A1 in 25.44 and 5.80%, respectively, and to subgroup A2 in 22.04 and 9.89%, respectively. In all studied subgroups and age categories, NSAID were coprecribed in more than 20-35% of cases. Conclusions NSAID are frequently prescribed in elderly patients treated with ACEI or ARB in combination with diuretics. Severe renal adverse effects may result in this high-risk population. Copyright (C) 2008 John Wiley & Sons, Ltd.