Recruiting

Beta Blockers

Sponsor:

University of Texas Southwestern Medical Center

Code:

NCT06582680

Conditions

Heat Stress

Aging

Eligibility Criteria

Sex: All

Age: 65+

Healthy Volunteers: Accepted

Interventions

Ambient Heat

Study Details

Brief summary:

This study will test the hypothesis that the drugs propranolol and metoprolol will result in greater increases in core body temperature during 3 hours of extreme heat exposure in older adults.

Conditions

Heat Stress

Aging

Study ID

NCT06582680

Start date

Oct 4, 2024

Status verified date

Oct, 2025

Completion date

Sep 30, 2026

Anticipated

Primary completion date

Sep 30, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 65+

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Healthy and free of any significant medical problems
  • Normal resting electrocardiogram
  • 65+ years of age
  • Controlled cholesterol of less than 200 mg/dl
  • Controlled blood pressure of less than 140/90 mmHg

Exclusion Criteria:

  • Known diseases or other chronic conditions requiring regular medical therapy including cancer, diabetes, neurological diseases, uncontrolled hypertension, and uncontrolled hypercholesterolemia
  • Serious abnormalities detected on routine screening
  • Taking prescribed medications or over-the-counter medications that have known influences on either cardiac function or sweating
  • Current smokers, as well as individuals who regularly smoked within the past 3 years
  • body mass index ≥31 kg/m2

Study Design

Enrollment

22 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Placebo, then Propranolol, then Metoprolol

experimental: Placebo, then Metoprolol, then Propranolol

experimental: Propranolol, then Placebo, then Metoprolol

experimental: Propranolol, then Metoprolol, then Placebo

experimental: Metoprolol, then Placebo, then Propranolol

experimental: Metoprolol, then Propranolol, then Placebo

Interventions

Ambient Heat

Subjects will spend 3-hours in a heat chamber at 41°C and 40% humidity.

Primary outcome measure

  • Internal temperature [ Time Frame: Continuously throughout the 3-hour heat exposure. ]
  • Whole body sweat rate [ Time Frame: Nude body mass will be measured before and after the 3-hour heat exposure. ]

Central Contacts and Locations

Central contacts

Erin Harper, MS

214-345-4737erinharper@texashealth.org

Courtney Kirby, RN

214-345-6502courtneykirby@texashealth.org

Locations

IEEM Texas Health Presbyterian Hospital Dallas

Recruiting

Dallas, Texas, United States, 75231

Contacts

Taysom Wallace, MS

214-345-5022taysomwallace@texashealth.org

Courtney Kirby, RN

214-345-6502courtneykirby@texashealth.org

Principal Investigator:

Craig Crandall, PhD

More Information

Sponsor

University of Texas Southwestern Medical Center

Last update posted

Oct 23, 2025

Last verified

Oct, 2025

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by University of Texas Southwestern Medical Center on 2025-10-23.