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Extracellular Fluid in Resistant Hypertension

This study has been terminated.
(Insufficient accrual rate)
Information provided by:
St George's, University of London Identifier:
First received: August 31, 2005
Last updated: June 5, 2015
Last verified: May 2007
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 Intervention
Hypertension Drug: Cardura XL 4 mg bd Drug: Amiloride 5 mg bd Drug: Furosemide 40 mg bd

Study Type: Interventional
Study Design: 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

Further study details as provided by St George's, University of London:

Primary Outcome Measures:
  • Change in ECV; change in BP

Estimated Enrollment: 32
Study Start Date: July 2003
Study Completion Date: October 2006
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.

Ages Eligible for Study:   18 Years to 80 Years   (Adult, Senior)
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
  Contacts and Locations
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Please refer to this study by its identifier: NCT00141596

United Kingdom
Blood Pressure Unit, Dept. Cardiac & Vascular Sciences, SGUL
London, United Kingdom, SW17 0RE
Sponsors and Collaborators
St George's, University of London
Principal Investigator: Timothy WR Doulton, BSc MRCP SGUL
  More Information Identifier: NCT00141596     History of Changes
Other Study ID Numbers: LREC 03.0001
Study First Received: August 31, 2005
Last Updated: June 5, 2015

Keywords provided by St George's, University of London:
Resistant Hypertension
Extracellular Fluid Volume

Additional relevant MeSH terms:
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 processed this record on August 22, 2017