Pharmacogenomic Evaluation of Antihypertensive Responses 2

Overview[ - collapse ][ - ]

Purpose There are many medications available for the treatment of high blood pressure (hypertension), but finding the right one for a specific patient can be challenging. In fact, it is estimated that less than 50% of people with hypertension have their blood pressure under control. The hypothesis is that genetic differences between individuals influence their response to antihypertensive medications. This study is aimed at determining the genetic factors that may influence a person's response to either a beta-blocker or a thiazide diuretic. The hope is that through this research, the investigators may someday be able to use an individual's genetic information to guide the selection of their blood pressure medicine, leading to better control of blood pressure, and less need for the current trial and error process.
ConditionHypertension
InterventionDrug: metoprolol or chlorthalidone
PhasePhase 4
SponsorNational Institute of General Medical Sciences (NIGMS)
Responsible PartyNational Institute of General Medical Sciences (NIGMS)
ClinicalTrials.gov IdentifierNCT01203852
First ReceivedSeptember 15, 2010
Last UpdatedOctober 15, 2013
Last verifiedOctober 2013

Tracking Information[ + expand ][ + ]

First Received DateSeptember 15, 2010
Last Updated DateOctober 15, 2013
Start DateAugust 2010
Estimated Primary Completion DateMarch 2014
Current Primary Outcome Measuresantihypertensive response [Time Frame: after 6-8 weeks of treatment] [Designated as safety issue: No]antihypertensive response will be assessed by measuring blood pressure before and after treatment
Current Secondary Outcome Measuresadverse metabolic effects [Time Frame: after 6-8 weeks treatment] [Designated as safety issue: Yes]

Descriptive Information[ + expand ][ + ]

Brief TitlePharmacogenomic Evaluation of Antihypertensive Responses 2
Official TitlePharmacogenomic Evaluation of Antihypertensive Responses 2
Brief Summary
There are many medications available for the treatment of high blood pressure
(hypertension), but finding the right one for a specific patient can be challenging. In
fact, it is estimated that less than 50% of people with hypertension have their blood
pressure under control. The hypothesis is that genetic differences between individuals
influence their response to antihypertensive medications. This study is aimed at
determining the genetic factors that may influence a person's response to either a
beta-blocker or a thiazide diuretic. The hope is that through this research, the
investigators may someday be able to use an individual's genetic information to guide the
selection of their blood pressure medicine, leading to better control of blood pressure, and
less need for the current trial and error process.
Detailed Description
The proposed work should help move toward the long-term goal of selection of
antihypertensive drug therapy based on a patient's genetic make-up. Hypertension (HTN) is
the most common chronic disease for which drugs are prescribed, and the most prevalent risk
factor for heart attack, stroke, renal failure and heart failure. Responses to
antihypertensive drug therapy exhibit considerable interpatient variability, contributing to
poor rates of HTN control (currently about 40-50% in the US), and frequent nonadherence and
dropout from therapy. We propose to identify genetic predictors of the antihypertensive and
adverse metabolic responses to two preferred and pharmacodynamically contrasting drugs, a
beta-blocker (metoprolol) and a thiazide diuretic (chlorthalidone) in a sequential
monotherapy design in 400 hypertensive individuals. Data collected will include home and
clinic blood pressure, blood samples for testing for adverse metabolic effects and other
biomarkers, RNA, and DNA and urine sample. We will conduct genome-wide association SNP
genotyping and data from the study will be used for replication of findings from the
previous PEAR trial, along with new discoveries. The primary aims are to define the genetic
determinants of the antihypertensive response and adverse metabolic responses (e.g. changes
in glucose, triglycerides and uric acid). The proposed research is significant because
genetically-targeted antihypertensive therapy could lead to dramatically higher response
rates and fewer adverse effects than the usual trial-and-error approach. This would likely
lead to higher rates of HTN control, less need for polypharmacy, reduced health care costs,
and improved outcomes.
Study TypeInterventional
Study PhasePhase 4
Study DesignAllocation: Non-Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Crossover Assignment, Masking: Open Label, Primary Purpose: Treatment
ConditionHypertension
InterventionDrug: metoprolol or chlorthalidone
metoprolol 50 mg twice daily titrated to 100 mg twice daily chlorthalidone 15 mg daily titrated to 25 mg daily Note: due to discontinuation of the manufacture of chlorthalidone 15 mg, effective Jan 1, 2013; the starting dose of chlorthalidone will be 25 mg 4 times per week (Mon, Wed, Thur, Sat) with subsequent titration to 25 mg daily.
Study Arm (s)
  • Experimental: metoprolol
  • Experimental: chlorthalidone

Recruitment Information[ + expand ][ + ]

Recruitment StatusActive, not recruiting
Estimated Enrollment400
Estimated Completion DateMarch 2014
Estimated Primary Completion DateMarch 2014
Eligibility Criteria
Inclusion Criteria:

- An average seated home DBP > 85 mmHg and < 110 mmHg and home SBP < 180 mmHg.

- Subjects must also have an average seated (> 5 minutes) clinic DBP between 90 mmHg
and 110 mmHg and SBP < 180 mmHg

Exclusion Criteria:

- Secondary forms of HTN (including sleep apnea)

- Isolated systolic HTN

- Other diseases requiring treatment with BP lowering medications

- Heart rate < 55 beats/min (for metoprolol only)

- Known cardiovascular disease (including history of angina pectoris, heart failure,
presence of a cardiac pacemaker, history of myocardial infarction or
revascularization procedure, or cerebrovascular disease, including stroke and TIA)

- Diabetes mellitus (Type 1 or 2)

- Renal insufficiency (serum creatinine > 1.5 in men or 1.4 in women)

- Primary renal disease

- Pregnancy or lactation

- Liver enzymes > 2.5 upper limits of normal

- Current treatment with NSAIDS, COX2-inhibitors, oral contraceptives or estrogen.
GenderBoth
Ages18 Years
Accepts Healthy VolunteersNo
ContactsNot Provided
Location CountriesUnited States

Administrative Information[ + expand ][ + ]

NCT Number NCT01203852
Other Study ID NumbersU01 GM074492-06
Has Data Monitoring CommitteeYes
Information Provided ByNational Institute of General Medical Sciences (NIGMS)
Study SponsorNational Institute of General Medical Sciences (NIGMS)
CollaboratorsNot Provided
Investigators Principal Investigator: Julie A Johnson, PharmD University of Florida
Verification DateOctober 2013

Locations[ + expand ][ + ]

University of Florida
Gainesville, Florida, United States, 32610
Emory University
Atlanta, Georgia, United States
Mayo Clinic
Rochester, Minnesota, United States