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Extracellular Fluid in Resistant Hypertension

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT00141596
Recruitment Status : Terminated (Insufficient accrual rate)
First Posted : September 1, 2005
Last Update Posted : June 9, 2015
Information provided by:
St George's, University of London

Brief Summary:
The optimal treatment of drug resistant (defined as BP> 140/85 despite three anti-hypertensive drugs including a diuretic) is not well defined. This study aims to test the hypothesis that resistant hypertension is caused by excessive expansion of extracellular fluid volume. A secondary objective is to study which of three different antihypertensive drugs would be most useful in drug resistant hypertension.

Condition or disease Intervention/treatment Phase
Hypertension Drug: Cardura XL 4 mg bd Drug: Amiloride 5 mg bd Drug: Furosemide 40 mg bd Not Applicable

Detailed Description:
Following recruitment subjects will have ECV measured by 51Cr-EDTA determination of GFR, with Brochner-Mortensen correction applied. Subjects then receive the following drugs, in a randomised fashion, for a period of four weeks each, with BP & ECV measurement at end of each period: doxazosin GITS (Cardura XL) 4 mg b.d.; frusemide 40 mg b.d.; amiloride 5 mg b.d.; placebo.

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 32 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: A Study to Investigate the Contribution of Extracellular Fluid Volume Expansion to Drug Resistant Hypertension
Study Start Date : July 2003
Actual Study Completion Date : October 2006

Resource links provided by the National Library of Medicine

Primary Outcome Measures :
  1. Change in ECV; change in BP

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 80 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • BP >140/85
  • 3 antihypertensive drugs (ACE/ARB + calcium channel blocker + thiazide diuretic)

Exclusion Criteria:

  • Pregnancy
  • Breast Feeding
  • Unstable heart failure
  • Chronic Liver Disease
  • Creatinine >120 mcmol/L
  • Contraindication to (or intolerance of) drug used in study
  • BP > 180/110

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00141596

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United Kingdom
Blood Pressure Unit, Dept. Cardiac & Vascular Sciences, SGUL
London, United Kingdom, SW17 0RE
Sponsors and Collaborators
St George's, University of London
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Principal Investigator: Timothy WR Doulton, BSc MRCP SGUL
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ClinicalTrials.gov Identifier: NCT00141596    
Other Study ID Numbers: LREC 03.0001
First Posted: September 1, 2005    Key Record Dates
Last Update Posted: June 9, 2015
Last Verified: May 2007
Keywords provided by St George's, University of London:
Resistant Hypertension
Extracellular Fluid Volume
Additional relevant MeSH terms:
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Vascular Diseases
Cardiovascular Diseases
Natriuretic Agents
Physiological Effects of Drugs
Sodium Potassium Chloride Symporter Inhibitors
Membrane Transport Modulators
Molecular Mechanisms of Pharmacological Action
Acid Sensing Ion Channel Blockers
Sodium Channel Blockers
Epithelial Sodium Channel Blockers
Diuretics, Potassium Sparing