Combination Therapy with Olmesartan and Amlodipine in the Treatment of Hypertension

Background: Combination therapy with antihypertensive agents utilises different mechanisms of action and may be responsible for a more effective decrease in blood pressure. Objective: To review the recently published trials on efficacy and safety of the combination therapy with olmesartan and amlodipine. Results: The double-blind American COACH (Combination of Olmesartan Medoxomil and Amlopdine Besylate in Controlling High Blood Pressure) study (2008) showed in 1,940 patients that after eight weeks of treatment the BP goals were most frequently achieved in the 'combination therapy group', with 56.3% (54.1-58.5%) and 54.0% (51.8-56.2%) of patients reaching adequate blood pressure of < 140/90 mmHg with olmesartan/amlodipine 20/10 and 40/10 respectively. Combination therapy was generally well tolerated. The most common side effect was oedema [olmesartan 20 mg 9.9% (8.6-11.3%), amlodipine 10 mg 36.8% (34.7-39.0%), placebo 12.3% (10.9-13.8%)]. The frequency of oedema was lower in the groups combining amlodipine 10 mg with olmesartan 10 mg (26.5%, 24.5-28.5%), 20 mg (25.6%, 23.7-27.6%) or 40 mg (23.5%, 21.6-25.4%). In 2009 three double-blind controlled European studies including 500-1,000 patients each and performed independently of one another have confirmed the above study, and have demonstrated similar efficacy-safety effects from the combination of olmesartan medoxomil with amlodipine, particularly for patients not achieving adequate blood pressure control with olmesartan monotherapy. Conclusions: Combinations of olmesartan and amlodipine were significantly more effective at reducing blood pressure and realising guideline blood pressure goals in patients with mild to severe hypertension than monotherapy (with a placebo component). Combination therapy is well tolerated and is associated with a lower incidence of side effects, such as oedema, compared to monotherapy with high amlodipine dosages (10 mg).