Apply to Trial

Compensation: Varies

Number of Visits: 2

Duration: 2 weeks

Chlorthalidone for High Blood Pressure in Older Adults

Overseen ByTAKURO WASHIO, Ph.D.

Age: 18+

Sex: Any

Trial Phase: Phase < 1

Sponsor: University of Texas Southwestern Medical Center

Must not be taking: Hormonal therapy, others

Disqualifiers: Cardiovascular, Pulmonary, Diabetes, Alzheimer's, others

Approved in 2 JurisdictionsThis treatment is already approved in other countries

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to determine how the high blood pressure medication chlorthalidone affects brain health in older adults. High blood pressure can cause serious health issues, such as strokes, and may impact the brain. Researchers seek to understand if the medication alters brain blood flow and cognitive function. Participants will receive either the medication or a placebo for up to two weeks. The trial seeks older adults with high blood pressure, excluding those with severe heart or lung issues, diabetes, or other significant health conditions. As an Early Phase 1 trial, this research focuses on understanding the treatment's effects in people, offering participants a chance to contribute to groundbreaking research.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications, but it excludes those on three or more blood pressure medications. It's best to discuss your current medications with the trial team.

Is there any evidence suggesting that this treatment is likely to be safe for humans?

Research shows that chlorthalidone is generally well-tolerated for treating high blood pressure and effectively lowers it. Some patients might experience side effects, such as changes in blood mineral levels, which help maintain the body's fluid balance. Regular check-ups by healthcare providers can manage these side effects in most cases.

One large study compared chlorthalidone to another common high blood pressure medication and found no significant difference in major heart-related outcomes between the two. This finding suggests that chlorthalidone is a safe option for many people with high blood pressure. While minor side effects can occur, the overall safety of chlorthalidone makes it a good choice for controlling high blood pressure.¹ ² ³ ⁴ ⁵

Why do researchers think this study treatment might be promising?

Chlorthalidone is unique because it targets high blood pressure by acting as a diuretic, which helps the body get rid of extra salt and water, reducing blood volume. While many treatments for high blood pressure focus on relaxing blood vessels or blocking certain hormones, chlorthalidone's approach can lead to quick reductions in blood pressure levels. Researchers are excited about its potential for rapid effectiveness, possibly showing results in just one to two weeks, which is much faster than some other antihypertensive medications. This quick action makes it particularly appealing for older adults who might need swift blood pressure management.

What evidence suggests that chlorthalidone might be an effective treatment for high blood pressure?

Research has shown that chlorthalidone, which participants in this trial may receive, effectively manages high blood pressure. Studies have found that it controls blood pressure better over 24 hours compared to hydrochlorothiazide, another common medication. Chlorthalidone lowers both systolic and diastolic blood pressure more significantly. It also works for a longer duration, potentially improving heart health by reducing the risk of heart attacks. Overall, chlorthalidone is considered a strong choice for treating high blood pressure.¹ ² ⁴ ⁶ ⁷

Who Is on the Research Team?

TAKURO WASHIO, Ph.D.

Principal Investigator

UT Southwestern Medical Center

Are You a Good Fit for This Trial?

This trial is for older adults with high blood pressure who have not yet started treatment. Participants should be generally healthy, without conditions that could interfere with the study or pose additional risks.

Inclusion Criteria

I am between 60-85 years old with mild-to-moderate high blood pressure.

Exclusion Criteria

I have very high blood pressure or secondary hypertension.

Any history of substance abuse (other than tobacco)

Endurance-trained athletes

See 8 more

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive either antihypertensive drug treatment or placebo for 2 weeks to assess brain blood flow, cognitive function, and nervous system control

2 weeks

2 visits (in-person) before and after intervention

Follow-up

Participants are monitored for changes in cognitive performance, muscle sympathetic nerve activity, and cerebral blood flow

2 weeks

What Are the Treatments Tested in This Trial?

Interventions

Chlorthalidone

Trial Overview The study tests if chlorthalidone (a drug for high blood pressure) affects brain blood flow and cognitive function compared to a placebo over two weeks. Researchers will monitor changes in participants' brain health and nervous system regulation.

How Is the Trial Designed?

2Treatment groups

Active Control

Placebo Group

Group I: Antihypertensive drug treatment ArmActive Control1 Intervention

Participants will take a fixed dose of chlorthalidone (a diuretic, 12.5 mg or 25 mg orally once daily) for one to two week, with study visits for laboratory assessment at before and after intervention.

Group II: Placebo treatment ArmPlacebo Group1 Intervention

Participants will receive placebo treatment for one to two weeks, with study visits for laboratory assessment at before and after intervention.

Chlorthalidone is already approved in United States, European Union for the following indications:

Approved in United States as Chlorthalidone for:

Hypertension
Edema caused by heart failure, renal failure, hepatic cirrhosis, estrogen therapy, and other conditions

Approved in European Union as Chlortalidone for:

Hypertension
Edema

Find a Clinic Near You

Who Is Running the Clinical Trial?

University of Texas Southwestern Medical Center

Lead Sponsor

Trials

1,102

Recruited

1,077,000+

Published Research Related to This Trial

In a study of 29,873 older adults, chlorthalidone did not show a significant advantage over hydrochlorothiazide in reducing adverse cardiovascular events or deaths, with similar rates of these outcomes between the two medications.

However, patients taking chlorthalidone were significantly more likely to experience electrolyte imbalances, particularly hypokalemia, indicating a safety concern with its use in this population.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Chlorthalidone versus hydrochlorothiazide for the treatment of hypertension in older adults: a population-based cohort study.Dhalla, IA., Gomes, T., Yao, Z., et al.[2014]

The combination of azilsartan medoxomil and chlorthalidone significantly reduces blood pressure more effectively than other combinations, such as olmesartan medoxomil/hydrochlorothiazide, in four randomized controlled trials involving hypertensive patients.

This combination treatment is generally well tolerated, with only minor increases in serum creatinine and no significant impact on potassium levels, making it a safe option for managing hypertension.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Azilsartan medoxomil/chlorthalidone: a new fixed-dose combination antihypertensive.Pierini, D., Anderson, KV.[2017]

Citations

1.nejm.orgnejm.org/doi/full/10.1056/NEJMoa2212270

Chlorthalidone vs. Hydrochlorothiazide for Hypertension– ...Evidence suggests that chlorthalidone has a longer duration of action, with improved 24-hour blood-pressure control18,19 and other pleotropic ...

2.pmc.ncbi.nlm.nih.govpmc.ncbi.nlm.nih.gov/articles/PMC10220471/

Comparison of the Effectiveness and Safety of Chlorthalidone ...Our analysis showed that chlorthalidone was superior to hydrochlorothiazide in controlling both SBP and DBP, with no significant heterogeneity reported.

3.jamanetwork.comjamanetwork.com/journals/jamanetworkopen/fullarticle/2818672

Chlorthalidone vs Hydrochlorothiazide for Hypertension ...Previous research has indicated that CTD may offer better 24-hour BP control than HCTZ, potentially leading to more significant cardiovascular benefits.

4.ahajournals.orgahajournals.org/doi/10.1161/CIRCULATIONAHA.122.061029

Hydrochlorothiazide Versus Chlorthalidone: What Is the ...Furthermore, compared with hydrochlorothiazide, patients on chlorthalidone had significantly lower blood pressure and serum potassium and a ...

5.pmc.ncbi.nlm.nih.govpmc.ncbi.nlm.nih.gov/articles/PMC11831197/

Comparison of Cardiovascular Outcomes Between ...For secondary outcomes, cardiovascular mortality was 0.2% in both groups (p = 0.92). Myocardial infarction occurred in 0.3% of CLTD users and ...

6.jamanetwork.comjamanetwork.com/journals/jamainternalmedicine/fullarticle/2760777

Comparison of Cardiovascular and Safety Outcomes ...Ernst et al found better chlorthalidone nighttime blood pressure control at a 1:2 dose ratio, which could explain some increased safety signals.

7.cureus.comcureus.com/articles/241324-the-evolving-role-of-chlorthalidone-and-hydrochlorothiazide-as-first-line-treatments-for-hypertensive-patients

The Evolving Role of Chlorthalidone and ...According to some more recent studies, chlorthalidone was better at lowering blood pressure, but it carried an increased risk of electrolyte ...

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