Utilization patterns and drug budget impact of the angiotensin II receptor blockers

Abstract

The Angiotensin II Receptor Blockers (ARBs) are the latest drug class approved for hypertension treatment. The aims of this study were: (1) to identify patient characteristics associated with ARB use over time when compared to each of the other therapeutic classes approved for hypertension treatment, and (2) to evaluate the drug budget impact surrounding the introduction of ARBs in the United Kingdom (U.K.).;Data sources included The Health Improvement Network database, an electronic medical record dataset of patients seen by general practitioners in the U.K., and the Chemist & Druggist monthly drug price list from January, 2005. Immediately after the first ARB introduction (1995--1997), patients with high blood pressure readings and patients seen by a Cardiologist were more likely to receive prescriptions for ARBs than other antihypertensive classes. This did not persist for the more recent time period comprising 2001--2003. Over time, prescriptions for antihypertensive drugs for patients with diabetes shifted away from all classes, except the Angiotensin Converting Enzyme inhibitor class (ACEi), towards ARB treatment. For patients with heart failure, there was a statistically significantly shift away from prescribing ARBs towards the Beta Blocker and "Other" classes. In general, patients with diabetes or heart failure were more frequently prescribed ACEi than ARB therapy.;Among prescriptions for drugs approved for hypertension treatment, ARB prescription frequency increased from 0.04% in 1995 to 6.57% in 2004. Expenditures for drugs approved for hypertension treatment were estimated at £465,862,416 in 1995 and £1,458,268,104 in 2004 (2005 British Pounds values). This represents a 213% real rate of increase. Of the increase in average antihypertensive drug expenditures per prescription identified from 1995 to 2004, the use of ARBs accounted for only 5.8% to 9.3%. A shift towards more expensive treatments, increase in treatment prevalence and increasing use of more prescriptions per patient over time all contributed to the increased antihypertensive drug budget.;This study highlights that the ARBs are being used with caution in the U.K. and that the antihypertensive drug budget increase during the first 10 years of the ARB market life is explained by several factors besides ARB use.