Is the fixed-dose combination of telmisartan and hydrochlorothiazide a good approach to treat hypertension?

Abstract

Blockade of the renin-angiotensin system with selective AT1 receptor antagonists is recognized as an effective mean to lower blood pressure in hypertensive patients. Among the class of AT1 receptor antagonists, telmisartan offers the advantage of a very long half-life. This enables blood pressure control over 24 hours using once-daily administration. The combination of telmisartan with hydrochlorothiazide is a logical step because numerous previous studies have demonstrated that sodium depletion enhances the antihypertensive efficacy of drugs interfering with the activity of the renin-angiotensin system (RAS). In accordance with past experience using similar compounds blocking the RAS, several controlled studies have now demonstrated that the fixed-dose combination oftelmisartan/hydrochlorothiazide is superior in lowering blood pressure than either telmisartan or hydrochlorothiazide alone. Of clinical interest also is the observation that the excellent clinical tolerance of the angiotensin II receptor antagonist is not affected by the association of the low-dose thiazide. Thus telmisartan/hydrochlorothiazide is an effective and well-tolerated antihypertensive combination. Finally, the development of fixed-dose combinations should improve drug adherence because of the one-pill-a-day regimen.

Figure 1

Telmisartan plus hydrochlorothiazide (HTCZ) combined therapy offsets the effects of hydrochlorothiazide on serum potassium levels (derived from data McGill et al 2001b).

Figure 2

Drug-related adverse events, incidence of peripheral edema, and discontinuation rates in the ATHOS Study (derived from data of Neldam et al 2006). Abbreviations: HTCZ, hydrochlorothiazide.

Figure 3

Drug-related adverse events, incidence of cough, and discontinuation rates in a study comparing telmisartan plus hydrochlorothiazide (HTCZ) with enalapril plus hydrochlorothiazide in patients with mild to moderate hypertension (derived from data of Karlberg et al 1999).