The effect of combination therapy with an L/N-Type Ca(2+) channel blocker, cilnidipine, and an angiotensin II receptor blocker on the blood pressure and heart rate in Japanese hypertensive patients: an observational study conducted in Japan.

Recently, the use of combination therapy with a calcium channel blocker (CCB) and an angiotensin II receptor blocker (ARB) has been rapidly increasing. Although this combination therapy is accepted as a standard treatment hypertension, there have been few large-scale, multicenter studies examining its safety and efficacy. The present study was designed to investigate the safety and efficacy of adding cilnidipine, a dual L/N-type CCB, to the regimen of patients whose blood pressure had been poorly controlled (systolic blood pressure [SBP] >140 mmHg or diastolic blood pressure [DBP] >90 mmHg) by antihypertensive monotherapy with an ARB. The percentage achievement of the blood pressure goals recommended by the JSH 2000 guidelines was also assessed for at least 12 weeks of treatment. A total of 2,920 patients were enrolled in the study at 471 institutions in Japan from February 2003 to July 2004. The incidence of adverse reactions related to cilnidipine was as low as 2.5%. A significant reduction from the baseline was found both in SBP (from 164.1 +/- 15.3 to 139.2 +/- 15.3 mmHg, p<0.0001) and DBP (from 91.7 +/- 11.4 to 79.3 +/- 10.7 mmHg, p<0.0001). A total of 31.5% of the patients achieved the blood pressure goals recommended by the JSH 2000 guidelines. Moreover, the heart rate also significantly decreased in these patients, particularly in those with a higher baseline heart rate. Our results indicate that cilnidipine can be used in combination with an ARB to control blood pressure without any significant adverse effects, and also that cilnidipine successfully reduces elevated heart rate, which is a possible risk factor for cardiovascular events.