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

Abstract

To analyse the conditions of use of the drug combination in outpatients. 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. The exhaustive population under procedure 1 consisted of 3620 patients (71 +/- 11 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. The use of the drug combination in general practice was mainly inappropriate.