DrugLib.com — Drug Information Portal

Rx drug information, pharmaceutical research, clinical trials, news, and more

Mechanisms of Refractory Hypertension (Carvedilol)

Information source: University of Alabama at Birmingham
ClinicalTrials.gov processed this data on August 23, 2015
Link to the current ClinicalTrials.gov record.

Condition(s) targeted: Hypertensive

Intervention: Carvedilol (Drug); Chlorthalidone (Drug)

Phase: N/A

Status: Recruiting

Sponsored by: University of Alabama at Birmingham

Official(s) and/or principal investigator(s):
David A. Calhoun, MD, Principal Investigator, Affiliation: Cardiology Department - University of Alabama at Birmingham

Overall contact:
Felice Cook, Phone: 205-934-1400, Email: fycook@uab.edu


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.

Clinical Details

Study design: Allocation: Randomized, Endpoint Classification: Safety Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Investigator), Primary Purpose: Treatment

Primary outcome: % of subjects who achieve BP control (<140/90 mm Hg)

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.


Minimum age: 19 Years. Maximum age: 70 Years. Gender(s): Both.


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


- Pregnant or breast-feeding women

- Known hypersensitivity to chlorthalidone or other sulfonamide-derived drugs

Locations and Contacts

Felice Cook, Phone: 205-934-1400, Email: fycook@uab.edu

David A. Calhoun, MD, Birmingham, Alabama 35294, United States; Recruiting
David A. Calhoun, MD, Phone: 205-934-4633, Email: dcalhoun@uab.edu
Additional Information

Starting date: February 2015
Last updated: August 17, 2015

Page last updated: August 23, 2015

-- advertisement -- The American Red Cross
Home | About Us | Contact Us | Site usage policy | Privacy policy

All Rights reserved - Copyright DrugLib.com, 2006-2017