Description of antihypertensive use in patients with resistant hypertension prescribed four or more agents.

Data describing the use of recommended antihypertensive agents in the resistant hypertension population are limited. Treatment recommendations for resistant hypertension include maximizing diuretic therapy by using chlorthalidone and/or adding an aldosterone antagonist. Additional recommendations include combining antihypertensive agents from different drug classes. This retrospective cohort study describes antihypertensive use in patients with resistant hypertension defined as the concurrent use of ≥4 antihypertensive agents. Claims data from the Medstat MarketScan Commercial Claims and Encounter database were used to identify patients with resistant hypertension based on International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) diagnosis codes and National Drug Codes between May 1, 2008 and June 30, 2009. Of the 5 442 410 patients with hypertension in the database, 140 126 met study criteria. The most frequently prescribed antihypertensive classes were angiotensin-converting enzyme inhibitors and/or angiotensin receptor blockers (96.2%), diuretics (93.2%), calcium channel blockers (83.6%), and β-blockers (80.0%). Only 3.0% and 5.9% of patients were on chlorthalidone or an aldosterone antagonist, respectively. A total of 15.6% of patients were treated with angiotensin-converting enzyme inhibitor plus angiotensin receptor blocker. Our findings demonstrate that frequently prescribed antihypertensive agents for the treatment of resistant hypertension included guideline-recommended first-line agents. However, evidence-based and recommended agents, such as chlorthalidone and aldosterone antagonists, were underused. Moreover, minimally efficacious combinations, such as an angiotensin-converting enzyme inhibitor with an angiotensin receptor blocker, were prescribed at higher rates than evidence-based and recommended agents.