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Pharmacogenomic Evaluation of Antihypertensive Responses 2

Pharmacogenomic Evaluation of Antihypertensive Responses 2

Status
Completed
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01203852
Acronym
PEAR2
Enrollment
839
Registered
2010-09-16
Start date
2010-08-31
Completion date
2014-04-30
Last updated
2018-04-06

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Hypertension

Keywords

hypertension, antihypertensive drug, pharmacogenetics, genetics, blood pressure, glucose

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 single nucleotide polymorphism (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.

Interventions

DRUGMetoprolol

Metoprolol 50 mg twice daily titrated to 100 mg twice 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.

DRUGChlorthalidone

Chlorthalidone 25 mg 4 times per week titrated to 25 mg daily

Sponsors

National Institute of General Medical Sciences (NIGMS)
CollaboratorNIH
University of Florida
Lead SponsorOTHER

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No

Inclusion criteria

* An average seated home diastolic blood pressure (DBP) \> 85 mmHg and \< 110 mmHg and home systolic blood pressure (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 hypertension (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, cyclooxygenase-2 (COX2) inhibitors, oral contraceptives or estrogen.

Design outcomes

Primary

MeasureTime frameDescription
Change in Blood Pressure From Baseline to Treatmentafter 6-8 weeks of treatmentResponse to blood pressure medication will be assessed by measuring blood pressure before and after treatment

Secondary

MeasureTime frameDescription
Adverse Metabolic Effectsafter 6-8 weeks treatmentChange in glucose after treatment with study medication

Countries

United States

Participant flow

Recruitment details

The first subject was recruited on 8/10/10 and the final patient was recruited on 9/30/2013. Subjects were recruited from family medicine clinics and were identified through providers daily schedules, medical records, and encounter forms.

Pre-assignment details

Healthy volunteers with mild to moderate primary hypertension between the ages of 18-70 were eligible for the study. Subjects were washed-out from their hypertension medication prior to beginning study protocol. Participants with elevated systolic blood pressure greater than 180 mmHg after wash-out were excluded from the study.

Participants by arm

ArmCount
Metoprolol + Chlorthalidone
This group was assigned to the following: Metoprolol tartrate 50 mg twice daily for two weeks. After two weeks subjects will be seen in clinic and will have the dose doubled to 100 mg twice daily if either their HBP average or OBP is \> 120/70 mmHg. They will continue on this dose for an additional 6 weeks. Then will washout from all study medication. After washout, participants will initiate chlorthalidone 25 mg four times per week (Monday, Wednesday, Thursday, Saturday) for two weeks, then 25 mg daily of chlorthalidone for 6 weeks. Metoprolol: Metoprolol 50 mg twice daily titrated to 100 mg twice daily Chlorthalidone: Chlorthalidone 25 mg 4 times per week 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.
839
Total839

Withdrawals & dropouts

PeriodReasonFG000
Metoprolol 8 WeeksPhysician Decision470
Washout 2 WeeksPhysician Decision46

Baseline characteristics

CharacteristicMetoprolol + Chlorthalidone
Age, Categorical
<=18 years
0 Participants
Age, Categorical
>=65 years
0 Participants
Age, Categorical
Between 18 and 65 years
839 Participants
Age, Continuous50.3 years
STANDARD_DEVIATION 9
Region of Enrollment
United States
839 participants
Sex: Female, Male
Female
429 Participants
Sex: Female, Male
Male
410 Participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
— / —
other
Total, other adverse events
114 / 839
serious
Total, serious adverse events
3 / 839

Outcome results

Primary

Change in Blood Pressure From Baseline to Treatment

Response to blood pressure medication will be assessed by measuring blood pressure before and after treatment

Time frame: after 6-8 weeks of treatment

Population: All patients with antihypertensive response data. 282 patients completed all 3 study periods. 369 patients completed only period 1. 328 patients completed only period 3.

ArmMeasureGroupValue (MEAN)Dispersion
Metoprolol + ChlorthalidoneChange in Blood Pressure From Baseline to Treatmentdiastolic blood pressure response-7.56 mmHgStandard Deviation 6.39
Metoprolol + ChlorthalidoneChange in Blood Pressure From Baseline to Treatmentsystolic blood pressure response-11.70 mmHgStandard Deviation 9.51
Metorprolol OnlyChange in Blood Pressure From Baseline to Treatmentdiastolic blood pressure response-7.97 mmHgStandard Deviation 6.48
Metorprolol OnlyChange in Blood Pressure From Baseline to Treatmentsystolic blood pressure response-7.45 mmHgStandard Deviation 9.85
Chlorthalidone OnlyChange in Blood Pressure From Baseline to Treatmentdiastolic blood pressure response-7.68 mmHgStandard Deviation 5.84
Chlorthalidone OnlyChange in Blood Pressure From Baseline to Treatmentsystolic blood pressure response-13.65 mmHgStandard Deviation 9.55
p-value: <0.0001t-test, 1 sided
Secondary

Adverse Metabolic Effects

Change in glucose after treatment with study medication

Time frame: after 6-8 weeks treatment

Population: All patients with change in glucose data

ArmMeasureGroupValue (MEAN)Dispersion
Metoprolol + ChlorthalidoneAdverse Metabolic Effectsglucose response to metoprolol (n=365)1.02 mg/dLStandard Deviation 9.83
Metoprolol + ChlorthalidoneAdverse Metabolic Effectsglucose response to chlorthalidone (n=318)5.12 mg/dLStandard Deviation 10.6
Comparison: Mean glucose change after treatment with chlorthalidonep-value: <0.0001t-test, 1 sided
Comparison: Mean glucose change after treatment with metoprololp-value: 0.049t-test, 1 sided

Source: ClinicalTrials.gov · Data processed: Mar 7, 2026