An 8-week multicenter, randomized, double-blind, placebo controlled, parallel group factorial study in patients with mild to severe hypertension was conducted to determine if treatment with amlodipine and olmesartan medoxomil tablets was associated with clinically significant reduction in blood pressure compared to the respective monotherapies. The study randomized 1940 patients equally to one of the following 12 treatment arms: placebo, monotherapy treatment with amlodipine 5 mg or 10 mg, monotherapy treatment with olmesartan medoxomil 10 mg, 20 mg, or 40 mg, or combination therapy with amlodipine/ olmesartan medoxomil at doses of 5/10 mg, 5/20 mg, 5/40 mg, 10/10 mg, 10/20 mg, and 10/40 mg. Patients discontinued their prior antihypertensive treatment. The mean baseline blood pressure of the study population was 164/102 mmHg. Of the total cohort, 970 patients were treated with the combination as initial therapy.

Treatment with amlodipine and olmesartan medoxomil tablets resulted in statistically significant greater reductions in diastolic and systolic blood pressure compared to the respective monotherapy components. Maximum antihypertensive effects were attained within 2 weeks after a change in dose.

The following table presents the results for mean reduction in seated systolic and diastolic blood pressure following 8 weeks of treatment with amlodipine and olmesartan medoxomil tablets. Placebo-adjusted reductions from baseline in blood pressure were progressively greater with increases in dose of both amlodipine and olmesartan medoxomil components of amlodipine and olmesartan medoxomil tablets.

The antihypertensive effect of amlodipine and olmesartan medoxomil tablets was similar in patients with and without prior antihypertensive medication use, in patients with and without diabetes, in patients ≥65 years of age and <65 years of age, and in women and men. Limited data exist in patients ≥75 years of age.

Amlodipine and olmesartan medoxomil tablets was effective in treating black patients (usually a low-renin population), and the magnitude of blood pressure reduction in black patients approached that observed for non-Black patients. This effect in black patients has been seen with ACE inhibitors, angiotensin receptor blockers, and beta-blockers.

The blood pressure lowering effect was maintained throughout the 24-hour period with amlodipine and olmesartan medoxomil tablets once daily, with trough-to-peak ratios for systolic and diastolic response between 71% and 82%.

Upon completing the 8-week, double-blind, placebo-controlled study, 1684 patients entered a 44-week open-label extension and received combination therapy with amlodipine 5 mg plus olmesartan medoxomil 40 mg. During the open-label extension, patients whose blood pressure was not adequately controlled (i.e., did not achieve a blood pressure goal of <140/90 mmHg, or <130/80 mmHg for those patients with diabetes) on amlodipine/olmesartan medoxomil 5/40 mg were titrated to amlodipine /olmesartan medoxomil 10/40 mg. Patients whose blood pressure was still not adequately controlled were offered additional hydrochlorothiazide 12.5 mg and subsequently 25 mg as required to achieve adequate blood pressure goal.

There are no trials of amlodipine and olmesartan medoxomil tablets demonstrating reductions in cardiovascular risk in patients with hypertension, but at least one pharmacologically similar drug has demonstrated such benefits.