Extracellular Fluid in Resistant Hypertension

A Study to Investigate the Contribution of Extracellular Fluid Volume Expansion to Drug Resistant Hypertension

Status

Terminated

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00141596

Enrollment

Registered

2005-09-01

Start date

2003-07-31

Completion date

2006-10-31

Last updated

2015-06-09

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Hypertension

Keywords

Resistant Hypertension, Extracellular Fluid Volume

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.

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.

Interventions

DRUGCardura XL 4 mg bd

DRUGAmiloride 5 mg bd

DRUGFurosemide 40 mg bd

Study design

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

TREATMENT

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

18 Years to 80 Years

Healthy volunteers

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

Design outcomes

Primary

Measure	Time frame
Change in ECV; change in BP	—

Countries

United Kingdom

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026