Efficacy and tolerability of olmesartan medoxomil combined with amlodipine in patients with moderate to severe hypertension after amlodipine monotherapy: A randomized, double-blind, parallel-group, multicentre study

Background and objectives: Cerebrovascular and cardiac adverse events can be significantly reduced by effective antihypertensive therapy; however, BP control rates remain poor. The objective of this randomized, double-blind, parallel-group, multicentre study was to determine the efficacy and safety of olmesartan medoxomil/amlodipine combination therapy in patients with moderate to severe hypertension who had failed to respond to treatment with 8 weeks of open-label amlodipine. Methods: A total of 1017 patients entered the open-label amlodipine monotherapy stage; mean BP at week 0 was 164/102 mmHg. After 8 weeks of amlodipine monotherapy (5 mg/day), non-responding patients (n = 755) were randomized to receive placebo plus amlodipine 5 mg or a combination of olmesartan medoxomil (10-40 mg) with amlodipine 5 mg for 8 weeks. At week 16, patients who had achieved diastolic BP (DBP)