Clinical trial NCT00818883
Conditions: Essential Hypertension
Keywords: Essential Hypertension Hypertensive Blood Pressure, High Vascular Disease Cardiovascular Disease Drug Therapy
Sponsor: Takeda
Start date: 2009-02-01; Completion date: 2009-11-01
Enrollment: 609 participants; Allocation: RANDOMIZED; Intervention model: PARALLEL

Brief summary:
The purpose of this study is to compare the antihypertensive effect of chlorthalidone vs hydrochlorothiazide when each is used with azilsartan medoxomil, once daily (QD), in participants with moderate to severe essential hypertension.

Detailed description:
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 agents, hypertension remains inadequately controlled; only about one-third of patients continue to maintain control successfully.

Although most antihypertensive agents are effective at the appropriate dose, the majority have side effects that limit their use. As a class, angiotensin II receptor blockers generally are considered more tolerable than other classes of antihypertensive agents. TAK-491 (azilsartan medoxomil) is an angiotensin II receptor blocker being evaluated by Takeda to treat essential hypertension.

Treatments for essential hypertension commonly include use of a thiazide-like diuretic, either alone or as part of combination treatment. Although chlorthalidone was commonly prescribed in the past, its use has widely been replaced with hydrochlorothiazide, presumably due to a lack of available combination products containing chlorthalidone, the assumption that hydrochlorothiazide and chlorthalidone have similar antihypertensive effects and cardiovascular benefits, and the perception that chlorthalidone use is associated with a greater frequency of hypokalemia. However, the frequency of hypokalemia with chlorthalidone use is relatively low in the dose range of 12.5 to 25 mg and these doses have been shown to be associated with potent blood pressure reduction. Several long-term outcomes trials have shown that blood pressure reductions associated with chlorthalidone treatment reduce risk of cardiovascular morbidity and mortality.

Most hypertensive patients require two or more agents to achieve target blood pressure and diuretics are commonly used in combination with other antihypertensive agents. This trial is designed to compare chlorthalidone and hydrochlorothiazide when coadministered with azilsartan medoxomil.

Participants in this study will receive either chlorthalidone or hydrochlorothiazide in combination with azilsartan medoxomil. Total commitment time for this study is about 13 weeks. Participants will be required to wear a blood pressure monitor for three 24 hours periods during the study.

Arms: arm 1: None arm 2: None
Interventions: intervention 1: Azilsartan medoxomil and chlorthalidone intervention 2: Azilsartan medoxomil and hydrochlorothiazide
Intervention descriptions: intervention 1: Azilsartan medoxomil 40 mg and chlorthalidone 12.5 mg combination tablet, orally, once daily and hydrochlorothiazide placebo-matching tablets, orally, once daily for up to 10 weeks.

For participants who do not achieve target blood pressure by Week 6, the dose of chlorthalidone will be increased for the remaining 4 weeks of treatment. intervention 2: Azilsartan medoxomil 40 mg, tablets, orally, once daily and hydrochlorothiazide 12.5 mg, tablets, orally, once daily for up to 10 weeks.

For participants who do not achieve target blood pressure by Week 6, the dose of hydrochlorothiazide will be increased for the remaining 4 weeks of treatment.

Protocol documents: