Are prescribing patterns of diuretics in general practice good enough? A report from the More and Romsdal prescription study

Abstract

Objective: To examine general practitioners' (GPs) prescribing patterns of diuretics with respect to indications, drugs and doses to reveal possible needs for prescribing audits. Design: Observational, cross-sectional study. Setting: The Norwegian county More and Romsdal. Subjects: 1896 prescriptions for diuretics prescribed by GPs during two months. Main outcome measures: Prescriptions (drugs, strength of tablets, volume prescribed, directions for use). Diagnoses for prescribing. Results: Furosemide was prescribed most frequently (48.7%) followed by the compound diuretic of hydrochlorothiazide and amiloride (26.4%), thiazides and related drugs (13.0%), and spironolactone (5.8%). Diuretics were mainly prescribed for hypertension (48.4%), congestive heart failure (35.6%), and oedemas (e.g. orthostatic) (6.1%). The patients' mean age was 69.2 years; two of three were females. When thiazides and related drugs were prescribed for hypertension, we found that the daily dose was excessive in 37.2% of the cases. In congestive heart failure, furosemide was prescribed in about four of five cases, while bumetanide was prescribed in 1.5% of the cases. Conclusion: Our findings indicate that GPs need more knowledge about low-dose diuretic therapy in hypertension, about different diuretic regimens in heart failure, and about non drug treatment for orthostatic oedema. Clinical pharmacology regarding diuretics should be given priority in the vocational training and continuing education for GPs.