Effect of switching from amlodipine to combination therapy with telmisartan and low-dose hydrochlorothiazide

One of the most effective pairs in combination therapy is that of an inhibitor of the renin–angiotensin system (RAS) and a low-dose thiazide diuretic. Possible candidates for this combination therapy are hypertensive patients with blood pressure (BP) that is not controlled by a calcium channel blocker (CCB). Thus, we characterized the antihypertensive effect of the combination of telmisartan and low-dose hydrochlorothiazide in patients with hypertension that was not controlled by amlodipine, which is the most common CCB. A total of 75 patients with BP levels higher than 140/90 mm Hg, treated with 5 mg per day of amlodipine for at least 3 months, were divided into groups that were switched to treatment with 40–80 mg per day of telmisartan plus 12.5 mg per day of hydrochlorothiazide (TH, n=37) or that were continuously treated with 5–7.5 mg per day of amlodipine (Am, n=38). After 12 weeks of treatment, the mean BP level was significantly lower in the TH group than in the Am group (decrease in BP: −9.9±11.4 vs. −3.7±8.9 mm Hg, P<0.02; normalization rate: 67.6 vs. 30.3%, P<0.01). Serum uric acid was slightly higher in the TH group, but other laboratory data were not different between groups. Therefore, it is suggested that the combination of a RAS inhibitor and a low-dose thiazide is useful if treatment with a CCB cannot control BP in patients with hypertension.