Maximising antihypertensive effects of angiotensin II receptor blockers with thiazide diuretic combination therapy: focus on irbesartan/hydrochlorothiazide

Abstract

Background: Evidence-based guidelines for the management of hypertension are now well established. Studies have shown that more than 60% of patients with hypertension will require two or more drugs to achieve current treatment targets.

Discussion: Combination therapy is recommended as first-line treatment by the JNC-7 guidelines for patients with a blood pressure > 20 mmHg above the systolic goal or 10 mmHg above the diastolic goal, while the International Society of Hypertension in Blacks recommends combination therapy when BP exceeds targets by > 15/10 mmHg. Current European Society of Hypertension-European Society of Cardiology guidelines also recommend the use of low-dose combination therapy in the first-line setting. Furthermore, JNC-7 recommends that a thiazide-type diuretic should be part of initial first-line combination therapy. Thiazide/diuretic combinations are available for a variety of classes of antihypertensive, including ACE inhibitors, angiotensin receptor blockers (ARBs), beta blockers and centrally acting agents. This article focuses on clinical data investigating the combination of an ARB, irbesartan, with the diuretic, hydrochlorothiazide.

Conclusions: These data indicate that the ARB/HCTZ combination has greater potency and a similar side effect profile to ARB monotherapy and represents a highly effective approach for attaining goal BP levels using a therapeutic strategy that very effectively lowers BP, is well tolerated and minimises diuretic-induced metabolic effects.

Figure 1

Rates of (A) total AEs, (B) total discontinuations and (C) total discontinuations as a result of AEs in the groups that received valsartan 160 mg plus hydrochlorothiazide 12.5 mg (V + HCTZ12.5), valsartan 160 mg plus HCTZ 25 mg (V + HCTZ2S) and amlodipine 10 mg (A10) (44)

Figure 2

Comparison of the antihypertensive effects of irbesartan/HCTZ (150/12.5 mg) and valsartan/HCTZ (80/12.5 mg) in hypertensive patients: the COSIMA study (52). Reprinted with permission from the American Journal of Hypertension, Ltd

Figure 3

Percentage of patients achieving SeDBP < 90 mmHg during 7 weeks’ double-blind treatment of irbesartan/HCTZ combination therapy vs. irbesartan monotherapy (61)