Combination therapy is an effective strategy to increase antihypertensive efficacy in those patients with poor blood pressure (BP) control. In order to achieve BP targets, at least 75% of patients may require combination therapy, and European guidelines advocate this approach, particularly in those patients with a high cardiovascular risk. Evidence from large, randomized controlled trials, and the European hypertension treatment guidelines is supportive of the use of an angiotensin receptor blocker (ARB) with a calcium channel blocker (CCB). Fixed-dose combination formulations of olmesartan medoxomil, an ARB, and the CCB amlodipine are approved in several European countries for patients with essential hypertension. The olmesartan/amlodipine combination has demonstrated greater efficacy than its component monotherapies in reducing BP in patients with mild-to-severe hypertension. Significantly greater reductions in seated diastolic BP were observed between baseline and after eight weeks of treatment with olmesartan/amlodipine, compared with equivalent doses of olmesartan or amolodipine monotherapy (P < 0.001), in the factorial Combination of Olmesartan Medoxomil and Amlodipine Besylate in Controlling High Blood Pressure (COACH) trial. About 85% of the maximal BP reductions after the 8-week treatment period were already observed after two weeks. Uptitration as necessary, with or without hydrochlorothiazide, allowed the majority of patients to achieve BP control in a 44-week open-label extension treatment period to the COACH trial. The use of olmesartan/amlodipine allowed up to 54% of patients, with previously inadequate responses to amlodipine or olmesartan monotherapy, to achieve their BP goals. Data from post-registration studies using tight BP control and forced titration regimens have further demonstrated the high efficacy of olmesartan/amlodipine in achieving BP goal rates. Moreover, consistent reductions in BP were observed over the 24-hour dosing interval using ambulatory measurements. Olmesartan/amlodipine was generally well tolerated over the short-and longterm, with a lower frequency of peripheral edema with olmesartan/amlodipine 40/10 mg than with amlodipine 10 mg monotherapy.
