Prescription patterns of diuretics in Dutch community-dwelling elderly patients

Abstract

Aims: To describe age- and gender-related prescription patterns of diuretics in community-dwelling elderly, and to compare diuretics to other cardiovascular (CV) medications. Methods: Cross-sectional study of patient- specific prescription data derived from a panel of 10 Dutch community pharmacies. Determination of proportional prescription rates and prescribed daily dose (PDD) of diuretics, cardiac glycosides, nitrates, angiotensin converting enzyme (ACE) inhibitors, β-adrenoceptor blockers, and calcium channel blockers in all 5326 patients aged 65 years or older dispensed CV medications between August 1st, 1995 and February 1st, 1996. Results: Diuretics were prescribed to 2677 of 5326 patients (50.3%), 1325 patients (24.9%) using thiazides and 1198 patients (22.5%) using loop diuretics. Prescription rates of loop diuretics increased from 15.1% in patients aged 65-74 years to 37.2% in patients aged 85 years or older. Rates also increased for digoxin and nitrates. Rates for thiazide diuretics remained unchanged with age; rates for β-adrenoceptor blockers, ACE inhibitors and calcium channel blockers declined with age. Thiazides were prescribed to 30.1% of women compared with 16% of men (P<0.001). Average PDD was 135 ±117% of defined daily dose (DDD) for loop diuretics, and highest for bumetanide (245 ± 2.01% of DDD, equivalent to 2.5 ± 2.0 mg). Average PDD was 74 ± 40% of DDD for thiazides, and highest for chlorthalidone (100 ± 49% of DDD, equivalent to 25 ± 12 mg). Conclusions: Important characteristics of diuretic usage patterns in this elderly population were a steep increase in loop diuretic use in the oldest old, a large gender difference for thiazide use, and high prescribed doses for thiazides.