Official Title: “The Effects of Doxazosin Gastrointestinal Therapeutic System (GITS) on Ambulatory Blood Pressure and Cardiovascular Risk Factors in Uncontrolled Hypertensives on Drug Therapy”

The primary objective was to determine the effects of the Gastrointestinal Therapeutic System (GITS) formulation of Doxazosin when used in combination therapy with the 5 major classes of antihypertensive agents as measure by 24-hour diastolic blood pressure.

Study Type: Interventional

Study Design: Treatment, Non-Randomized, Open Label, Single Group Assignment, Safety/Efficacy Study

Study Primary Completion Date: February 2004

Intervention(s) in this Clinical Trial

• Drug: Doxazosin gastrointestinal therapeutic system (GITS)
  • 4 mg/day, and was titrated, if necessary, to 8 mg/day at Week 3 (Visit 5) or Week 5 (Visit 6).

Arms, Groups and Cohorts in this Clinical Trial

• Experimental: A

Primary Measures

• To determine the effects of Doxazosin Gastrointestinal Therapeutic System (GITS) 4 or 8mg/day on mean 24-hour diastolic ambulatory blood pressure (ABP) when used in combination therapy in subjects with uncontrolled essential hypertension.
  • Time Frame: 11 weeks
    Safety Issue?: No

Secondary Measures

• Serum lipid levels (total cholesterol [TC], HDL cholesterol, calculated LDL cholesterol, triglycerides, calculated HDL/TC ratio)
  • Time Frame: 9 weeks
    Safety Issue?: Yes
• HgbA1C
  • Time Frame: 9 weeks
    Safety Issue?: Yes
• 24-hour systolic ABP and 24-hour ambulatory heart rate
  • Time Frame: 9 weeks
    Safety Issue?: Yes
• daytime and nighttime (2200 to 0600 hours) ABP and ambulatory heart rate
  • Time Frame: 9 weeks
    Safety Issue?: Yes
• Sitting and standing clinic blood pressure (BP) and heart rate
  • Time Frame: 9 weeks
    Safety Issue?: Yes
• 24-hour ABP smoothness index
  • Time Frame: 9 weeks
    Safety Issue?: Yes
• 24-hour ABP and ambulatory heart rate between 24 hours (Week 9) and 48 hours (Week 9+1 day) after final dose of Doxazosin GITS
  • Time Frame: 9 weeks
    Safety Issue?: Yes

Inclusion Criteria:

• Eligible subjects were males or females ≥18 years of age with a diagnosis of primary essential hypertension and currently taking 1 or 2 individual antihypertensive agents
• Dosing for entry antihypertensive medication was at the accepted efficacious dose or the maximum tolerated dose and had to be stable for at least 4 weeks prior to study entry
• Subjects were required to have clinic sitting DBP ≥95 and ≤110 mmHg and SBP ≥140 and ≤180 mmHg as an average of 3 readings on their current antihypertensive therapy at visits 1 and 2

Exclusion Criteria:

Exclusion criteria included, but were not limited to:

• Subjects taking antihypertensive medications for other indications (i.e. arrhythrma, unstable angina, CHF, etc.)
• Orthostatic hypotension, defined as a decrease of at least 20 mmHg systolic or 1OmmHg diastolic pressure between sitting and standing blood pressures after 2 rmnutes, or known fluid depletion.

Gender Eligibility for this Clinical Trial: Both

Minimum Age for this Clinical Trial: 18 Years

Maximum Age for this Clinical Trial: N/A

Are Healthy Volunteers Accepted for this Clinical Trial?: No

Lead Sponsor: Pfizer

Overall Clinical Trial Officials and Contacts

Pfizer CT.gov Call Center Study Director Pfizer  

Information obtained from ClinicalTrials.gov on September 05, 2008

Link to the current ClinicalTrials.gov record. http://clinicaltrials.gov/show/NCT00646841

Study ID Number: A0351051

ClinicalTrials.gov Identifier: NCT00646841

Health Authority: United States: Food and Drug Administration

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