Double Blind Crossover Comparison of Diuretics in the Young

Low-Renin Hypertension Clinical Trial

Official title:

Double Blind Crossover Comparison od Diuretics in Young Patients With Low Renin Hypertension

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT00429897
• Other study ID #: 1.0
• Status: Recruiting
• Phase: N/A
• First received: January 31, 2007
• Last updated: January 31, 2007
• Start date: August 2006
• Est. completion date: July 2007

Study information

• Verified date: January 2007
• Source: University of Cambridge
• Contact: Morris J Brown, Professor
• Phone: 01223 336743
• Email: mjb14[@]medschl.cam.ac.uk
• Is FDA regulated: No
• Health authority: United Kingdom: Medicines and Healthcare Products Regulatory AgencyUnited Kingdom: Research Ethics Committee
• Study type: Interventional

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 30
• Est. completion date: July 2007
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years to 45 Years

Eligibility

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

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Crossover Assignment, Masking: Double-Blind, Primary Purpose: Treatment

Related Conditions & MeSH terms

• Hypertension
• Low-Renin Hypertension

Intervention

Drug:
• Bendroflumethiazide 2.5mg - 5mg

• Amiloride 20-40mg

• Spironolactone 50-100mg

• Frusemide 20-40mg

• Bendroflumethiazide 1.25-2.5mg/ Amiloride 10-20mg combined

Locations

Country	Name	City	State
United Kingdom	University of Cambridge - Addenbrookes Hospital	Cambridge

Sponsors (2)

Lead Sponsor	Collaborator
University of Cambridge	British Heart Foundation

Country where clinical trial is conducted

United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Difference in systolic blood pressure for subjects' best drug and second best drug.
Primary	Difference in plasma renin for subjects' best drug and second best drug.
Secondary	Predictions of best drug