Study of the use of a spironolactone and angiotensin-converting enzyme inhibitor combination:: a population-based analysis

Purpose To analyse the conditions of use of the drug combination in outpatients. Methodology The first section consisted of a population-based analysis using computerized records from the French national health insurance system. The study population consisted of adult patients, receiving long-term treatment with spironolactone (SPIR) and angiotensin-converting enzyme inhibitor (ACEI). For each patient, the reimbursement of serum potassium and creatinine determinations was searched for in the database during the 6-month period preceding the date of the last dispensation. The second section comprised a written questionnaire on use practises, sent to practitioners who prescribed the drug combination to randomly selected patients. Analysis of the answers to the questionnaire made it necessary to develop a reference system. In the third section, procedure one was repeated at a later stage, following an information campaign, in order to measure its impact. Results The exhaustive population under procedure I consisted of 3620 patients (71 I I years). During the 6 months prior to the index date, 51% of patients underwent at least one determination of both serum potassium and serum creatinine. The randomised population under procedure two consisted of 441 patients (70 13 years) and their 375 practitioners. When compared with the reference system, SPIR-ACEI was used for the recommended indications, at the appropriate SPIR-ACEI dosages, and under minimal monitoring of biological parameters in only 65 patients (15%). After the information campaign, results were disappointing because only 55% of patients underwent the minimal laboratory monitoring. Conclusion The use of the drug combination in general practice was mainly inappropriate. Copyright (C) 2007 John Wiley & Sons, Ltd.