Clinical trial NCT00591266
Conditions: Hypertension
Keywords: Blood pressure blood pressure monitoring ambulatory Drug Therapy
Sponsor: Takeda
Start date: 2007-10-01; Completion date: 2009-04-01
Enrollment: 566 participants; Allocation: RANDOMIZED; Intervention model: PARALLEL

Brief summary:
The purpose of this study is to evaluate the efficacy and safety of azilsartan medoxomil, once daily (QD), co-administered with amlodipine in treating individuals with essential hypertension, compared to treatment with amlodipine alone.

Detailed description:
Hypertension affects approximately 50 million individuals in the United States. As the population ages, the prevalence of hypertension will continue to increase if broad and effective preventive measures are not implemented. According to the World Health Organization, hypertension is the most common attributable cause of preventable death in developed nations, as uncontrolled hypertension greatly increases the risk of cardiovascular disease, cerebrovascular disease, and renal failure. Despite the availability of antihypertensive treatments, hypertension remains inadequately controlled; only about one third of patients continue to maintain control successfully.

A major component of blood pressure regulation is the renin-angiotensin-aldosterone system, a system of hormone-mediated feedback interactions that results in the relaxation or constriction of blood vessels in response to various stimuli. Angiotensin II, a polypeptide hormone, is formed from angiotensin I in a reaction catalyzed by angiotensin-converting enzyme as part of the renin-angiotensin-aldosterone system. Angiotensin II is the principal pressor agent of the renin-angiotensin-aldosterone system with a myriad of effects on the cardiovascular system and on electrolyte homeostasis.

Takeda Global Research \& Development Center, Inc. is developing TAK-491 (azilsartan medoxomil) to treat patients with essential hypertension. Azilsartan medoxomil is a prodrug that is hydrolyzed to the active moiety, azilsartan, which is a selective antagonist of the angiotensin II type 1 receptor subtype.

Amlodipine is a slow-channel blocker that inhibits the transmembrane influx of calcium ions into vascular smooth muscle and cardiac muscle. It is a peripheral arterial vasodilator that acts directly on vascular smooth muscle to cause a reduction in peripheral vascular resistance and reduction in blood pressure.

This study is being conducted to determine whether administration of azilsartan medoxomil in combination with amlodipine in participants with uncontrolled hypertension is more efficacious in reducing systolic blood pressure than amlodipine alone. Participation in this study is anticipated to be approximately 10 weeks.

Arms: arm 1: None arm 2: None arm 3: None
Interventions: intervention 1: Azilsartan Medoxomil and amlodipine intervention 2: Azilsartan Medoxomil and amlodipine intervention 3: Amlodipine
Intervention descriptions: intervention 1: Azilsartan Medoxomil 40 mg, tablets, orally, once daily and amlodipine 5 mg, tablets, orally, once daily for up to 6 weeks. intervention 2: Azilsartan Medoxomil 80 mg, tablets, orally, once daily and amlodipine 5 mg, tablets, orally, once daily for up to 6 weeks. intervention 3: Azilsartan medoxomil placebo-matching tablets, orally, once daily and amlodipine 5 mg, tablets, orally, once daily for up to 6 weeks.

Protocol documents: