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Mechanisms of Refractory Hypertension (Carvedilol)

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ClinicalTrials.gov Identifier: NCT02357004
Recruitment Status : Recruiting
First Posted : February 6, 2015
Last Update Posted : September 5, 2017
Sponsor:
Information provided by (Responsible Party):
David Calhoun, University of Alabama at Birmingham

Brief Summary:
The purpose of this protocol is test whether patients with hypertension refractory to antihypertensive treatment have evidence of excessive sympathetic (i.e., nervous system) activity.

Condition or disease Intervention/treatment Phase
Hypertensive Drug: Carvedilol Drug: Chlorthalidone Not Applicable

Detailed Description:
Refractory hypertension refers to high blood pressure that is failing conventional antihypertensive therapies. In a retrospective assessment of such patients in our clinic we observed that resting clinic heart rates were higher in patients with refractory hypertension compared to patients with controlled hypertension. This observation has led to the hypothesis that refractory hypertension is caused by excessive sympathetic output. This protocol is designed to test this hypothesis by comparing the BP response to carvedilol verses chlorthalidone in patients with refractory hypertension. If their extreme treatment resistance is neurogenic is etiology, a significantly larger BP response to carvedilol should occur compared to chlorthalidone.

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 100 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Treatment
Study Start Date : February 2015
Estimated Primary Completion Date : January 2019
Estimated Study Completion Date : January 2019

Resource links provided by the National Library of Medicine


Arm Intervention/treatment
Experimental: Carvedilol
Carvedilol CR 40 mg daily in addition to their normal BP medications. Subjects will be seen in follow-up at 2-week intervals for the duration of the 8-week intervention period. If the clinic BP remains elevated (>140/90 mmHg) at any of the follow-up visits, the study medication will be titrated up to carvedilol CR 80 mg daily (subjects will take 2 of the study pills).
Drug: Carvedilol
CR 40 mg daily in addition to normal BP medications

Experimental: Chlorthalidone
Chlorthalidone 12.5 mg daily in addition to their normal BP medications. Subjects will be seen in follow-up at 2-week intervals for the duration of the 8-week intervention period. If the clinic BP remains elevated (>140/90 mmHg) at any of the follow-up visits, the study medication will be titrated up to chlorthalidone 25 mg daily (subjects will take 2 of the study pills).
Drug: Chlorthalidone
12.5 mg daily in addition to normal BP medications




Primary Outcome Measures :
  1. % of subjects who achieve BP control (<140/90 mm Hg) [ Time Frame: 8 weeks after baseline ]
    BP will be measured 8 weeks after starting carvedilol and after starting chlorthaidone. The percent of subjects with BP of <140/90 mm HG in each group will be reported.



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Ages Eligible for Study:   19 Years to 70 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Uncontrolled clinic BP (>140/90 mmHg)
  • Receiving 5 or more antihypertensive agents including an ACE inhibitor or ARB, calcium channel blocker, and chlorthalidone 25 mg

Exclusion Criteria:

  • Current use of an alpha or beta or combined alpha-beta antagonist
  • Known allergy to alpha-beta antagonists
  • CKD (eGFR <40 ml/min/m2)
  • MI, stroke or episode of CHF exacerbation within 3 months
  • Bradycardia <50 bpm; history of 2nd or 3rd degree heart block unless treated by a pacemaker
  • Pregnant or breast-feeding women
  • Known hypersensitivity to chlorthalidone or other sulfonamide-derived drugs

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): NCT02357004


Contacts
Contact: Felice Cook 205-934-1400 fycook@uab.edu

Locations
United States, Alabama
David A. Calhoun, MD Recruiting
Birmingham, Alabama, United States, 35294
Contact: David A. Calhoun, MD    205-934-4633    dcalhoun@uab.edu   
Sponsors and Collaborators
University of Alabama at Birmingham
Investigators
Principal Investigator: David A. Calhoun, MD Cardiology Department - University of Alabama at Birmingham

Responsible Party: David Calhoun, Principal Investigator, University of Alabama at Birmingham
ClinicalTrials.gov Identifier: NCT02357004     History of Changes
Other Study ID Numbers: A000502641
First Posted: February 6, 2015    Key Record Dates
Last Update Posted: September 5, 2017
Last Verified: August 2017

Additional relevant MeSH terms:
Antihypertensive Agents
Carvedilol
Chlorthalidone
Adrenergic beta-Antagonists
Adrenergic Antagonists
Adrenergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Physiological Effects of Drugs
Vasodilator Agents
Adrenergic alpha-1 Receptor Antagonists
Adrenergic alpha-Antagonists
Diuretics
Natriuretic Agents
Sodium Chloride Symporter Inhibitors
Membrane Transport Modulators