Double Blind Crossover Comparison of Diuretics in the Young

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. Identifier: NCT00429897
Recruitment Status : Unknown
Verified January 2007 by University of Cambridge.
Recruitment status was:  Recruiting
First Posted : February 1, 2007
Last Update Posted : February 1, 2007
British Heart Foundation
Information provided by:
University of Cambridge

Brief Summary:

The principle objective of the study is to determine whether low-renin (i.e. salt sensitive) hypertension at a young age is caused by the kidneys hanging onto too much salt as a result of an over active salt pump in the kidney.

The kidneys have four different salt pumps, and each is blocked by a different type of diuretic (salt losing tablet)If one out of the four is overactive, we would expect patients to respond much better to one diuretic than to the alternatives - rather than responding equally well to all available types of diuretic.

Condition or disease Intervention/treatment Phase
Low-Renin Hypertension Drug: Bendroflumethiazide 2.5mg - 5mg Drug: Amiloride 20-40mg Drug: Spironolactone 50-100mg Drug: Frusemide 20-40mg Drug: Bendroflumethiazide 1.25-2.5mg/ Amiloride 10-20mg combined Not Applicable

Detailed Description:

Studies suggest that patients with low renin hypertension respond better to diuretics than other hypertensive drug groups. The aim of the study is to rotate patients through the four main diuretic groups and see if it is possible to identify the most effective diuretic for this group, as measured by a >=10mgHg decrease in Systolic blood pressure in one specific group a compared to the others.

As most caucasians with Low renin hypertension are older (>55), presentation with this type of hypertension at a younger age suggests the presence of substantial genetic variation in order to cause the atypical presentation. It is hoped that by identifying the best diuretic for these patients we will also be able to identify:

  1. Whether the young low-renin hypertensives can be sub-classified according to their most effective diuretic;
  2. Whether this sub-classification helps us to identify the genes and mutations responsible, since these are to expected to be in the so-called sodium channels (i.e. salt pumps)which the kidneys use to prevent salt being excreted in the urine.

Study Type : Interventional  (Clinical Trial)
Enrollment : 30 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double
Primary Purpose: Treatment
Official Title: Double Blind Crossover Comparison od Diuretics in Young Patients With Low Renin Hypertension
Study Start Date : August 2006
Study Completion Date : July 2007

Primary Outcome Measures :
  1. Difference in systolic blood pressure for subjects' best drug and second best drug.
  2. Difference in plasma renin for subjects' best drug and second best drug.

Secondary Outcome Measures :
  1. Predictions of best drug

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 45 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Aged 18-45
  • male or female
  • Hypertensive - 3 clinic SBP >=140mmHg; or 3 clinic DBP >=90mmHg; or ABPM or home BP >=130(SBP) or 85(DBP)
  • 24hr Na+<160mmol/l
  • EITHER {Plasma renin<=10mU/L (measured untreated, or whilst receiving only CCB+/-diuretic} + {Plasma renin <=40mU/L (measured on an ACEi or ARB, which approximately double s the plasma renin)} OR Plasma renin <5mU/L (measured untreated, or receiving any antihypertensive drug other than a beta-blocker

Exclusion Criteria:

  • Documented history of gout
  • Abnormal renal function (both elevated serum creatinine and reduced creatinine clearance
  • SBP > 170mmHg or Diastolic >110mmHg despite treatment with permitted background treatment

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 identifier (NCT number): NCT00429897

Contact: Morris J Brown, Professor 01223 336743

United Kingdom
University of Cambridge - Addenbrookes Hospital Recruiting
Cambridge, United Kingdom, CB2 2QQ
Contact: Morris J Brown, Proffessor    01223 336743   
Sub-Investigator: Sue Hood, RGN - sister         
Sub-Investigator: Diane Picton, RGN- sister         
Sub-Investigator: Tim Burton, Phd, MRCP         
Sponsors and Collaborators
University of Cambridge
British Heart Foundation
Principal Investigator: Morris J Brown, Proffessor Cambridge University Identifier: NCT00429897     History of Changes
Other Study ID Numbers: 1.0
First Posted: February 1, 2007    Key Record Dates
Last Update Posted: February 1, 2007
Last Verified: January 2007

Keywords provided by University of Cambridge:
Low Renin

Additional relevant MeSH terms:
Vascular Diseases
Cardiovascular Diseases
Natriuretic Agents
Physiological Effects of Drugs
Mineralocorticoid Receptor Antagonists
Hormone Antagonists
Hormones, Hormone Substitutes, and Hormone Antagonists
Diuretics, Potassium Sparing
Acid Sensing Ion Channel Blockers
Sodium Channel Blockers
Membrane Transport Modulators
Molecular Mechanisms of Pharmacological Action
Epithelial Sodium Channel Blockers
Antihypertensive Agents
Sodium Chloride Symporter Inhibitors