Efficacy and safety of combination therapy using high- or low-dose hydrochlorothiazide with valsartan or other angiotensin-receptor blockers

Abstract

Only a minority of patients treated for hypertension achieve controlled blood pressure (BP) levels. Therapy with fixed-dose combinations of an angiotensinreceptor blocker (ARB) and low-dose hydrochlorothiazide (HCTZ) is commonly prescribed but not always sufficient to achieve the target BP. The efficacy and safety of the fixed-dose combination of valsartan 160 mg and HCTZ 25 mg was evaluated in patients in whom BP had not been controlled with a fixed-dose combination of another ARB and low-dose HCTZ (12.5 mg) in a multicenter trial. After a wash-out period for antihypertensive drugs, patients with a mean sitting diastolic BP (DBP) at trough (3)100 mm Hg but <110 mm Hg were treated with candesartan cilexetil 16 mg plus HCTZ 12.5 mg or telmisartan 80 mg plus HCTZ 12.5 mg for 4 weeks (phase 1). Patients whose BP was still uncontrolled (DBP (3)90 mm Hg) after 4 weeks of therapy were then given valsartan 160 mg plus HCTZ 25 mg for an additional 4 weeks (phase 2). The primary efficacy parameter was the reduction in DBP between week 4 and week 8 in the intention-to-treat (ITT) population. BP reduction during phase 1 was -14.3+/-11.3/-7.5+/-3.9 mm Hg. DBP was controlled in 26% of the patients after phase 1. In patients treated with valsartan 160 mg plus HCTZ 25 mg during phase 2, DBP decreased by an additional 10.3+/-6.5 mm Hg and the mean sitting systolic BP (SBP) by an additional 11.0+/-11.7 mm Hg. The additional decrease was significant (P<.0001) for both parameters and independent of the fixed-dose combination used during phase 1. Among patients whose BP remained uncontrolled during phase 1, 74% achieved a controlled DBP after phase 2. The incidence of adverse events during both phases was comparably low and the results of laboratory tests were unremarkable. Treatment with valsartan 160 mg/HCTZ 25 mg offered a substantial benefit for patients with hypertension not controlled with the combination of candesartan cilexetil 16 mg or telmisartan 80 mg and low dose HCTZ, while maintaining a comparable safety and tolerability profile.