Pharmacological Countermeasures for High Altitude

March 25, 2025 updated by: Roy Salgado, United States Army Research Institute of Environmental Medicine

Augmentation of Medical Readiness and Physical Performance at High Altitude Using Pharmacological Countermeasures

The aim of this randomized, double-blind study is to determine whether erythropoietin (Procrit) and acetazolamide: 1) mitigates altitude-induced decrements in performance at moderate altitude (3,000 m) and 2) mitigates altitude-induced decrements in performance and reduce acute mountain sickness during prolonged exposure to high altitude (4,300 m; 15 days). Volunteers will complete 5 study phases: Phase 1) sea level baseline testing and a moderate altitude exposure; Phase 2) 4 week study intervention - randomly assigned to receive erythropoietin or placebo); Phase 3) 3 1/2 days of acetazolamide and a moderate altitude exposure; Phase 4) high altitude acclimatization - 15 days at Pikes Peak; and Phase 5) two week deacclimatization. Test battery include VO2peak, 3.2 km treadmill time trial, measures of gas exchange and ventilation during rest and exercise, and blood collection.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This study will use a double-blind randomized study design in which one group will receive erythropoietin and the other a placebo (saline) for 4 weeks, then both groups will receive acetazolamide. Eighteen men and women volunteers will complete 5 study phases: Phase 1) two week sea level baseline testing (orientation, two VO2peak assessments, three 3.2 km treadmill time-trial, assessment of resting ventilation, venipuncture and capillary blood collection, and Hbmass assessment), and a VO2peak and 3.2 km treadmill time-trial moderate altitude (3,000 m); Phase 2) 4 week intervention to receive subcutaneously erythropoietin or placebo. The erythropoietin (Procrit) dosing regimen will consist of 50 IU/kg three times a week (M-W-F); Phase 3) a second moderate altitude exposure (VO2peak and 3.2 km treadmill time-trial with acetazolamide administered (orally; 250 mg b.i.d) for 3 1/2 nights starting the day before the altitude exposure; Phase 4) high altitude acclimatization in which volunteers will reside for 15 days at 4,300 m altitude (Pikes Peak, Colorado Springs) completing multiple VO2peak assessments and 3.2 km treadmill time-trials, resting ventilation, venipuncture and capillary blood collection; and Phase 5) deacclimatization phase to assess changes in hematological biomarkers after returning from Pikes Peak. This study consists of 41 visits over a ~10 week time period. Visits will take place in Natick, MA and the Pikes Peak High Altitude Research Laboratory at Colorado Springs. Additional assessments that will be completed multiple times during the study include: acute mountain sickness questionnaire, lung gas diffusion at rest and during exercise, oxygen saturation, arterialized blood gases (PO2, PCO2, pH, HCO3) and heart rate during rest, exercise, and sleep, and muscle tissue oxygenation. The primary outcome is 3.2 km treadmill time-trial performance. Secondary outcomes include: incidence and severity of acute mountain sickness, ventilation and gas exchange, Hbmass, Hb concentration, Hct, arterialized blood gases, lung diffusion at rest and during exercise, oxygen saturation and heart rate during rest, exercise, and sleep.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
18

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • Massachusetts
      • Natick, Massachusetts, United States, 01760
        • USARIEM

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 40 years (Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Age 18-40 years
  • In good health as determined by the Office of Medical Support & Oversight (OMSO) General Medical Clearance
  • Runs at least 3 times per week and able to complete a two mile run in ≤ 21 minutes (Civilian Volunteers) or passed his/her most recent Army Combat Fitness Test (ACFT) (Military Volunteers Only)
  • Willing to not exercise, or drink alcoholic and/or caffeinated beverages 24 hours prior to each testing session or the acute altitude exposure to 3,000 m
  • Abstain from alcoholic beverages during the 15 day residence at the summit of Pikes Peak
  • Abstain from drinking alcohol or caffeine at least 24 hours before a testing session during Phases 1 and 3
  • Willing to stay and exercise in an altitude chamber (the size of a dorm room) for ~2.5 hours
  • Wiling to reside at the summit of Pikes Peak (4,300 m altitude) and share dormitory area (bunk area, shower, and bathroom), potentially with people of the opposite sex for 15 days
  • Up to date on COVID-19 vaccination

Exclusion Criteria:

  • Women who are pregnant or planning to become pregnant during the study
  • Taking prescription medication, or over-the-counter medications other than contraceptives, unless approved by OMSO & PI
  • Born at altitudes greater than 2,100 m (7,000 ft)
  • Living in areas that are more than 1,200 m (4,000 ft) or have traveled to areas that are more than 1,200 m for five days or more within the last 2 months
  • Prior diagnosis of High Altitude Pulmonary Edema (HAPE) or High Altitude Cerebral Edema (HACE)
  • Musculoskeletal injuries that compromise the ability to walk/run on a treadmill or hike steep terrain
  • Abnormal blood count in accordance with OMSO - Normal Hb men: 12.6-17.7 g·dL-1 and women: 11.1-15.9 g·dL-1 or Normal Hct men: 37.5-48% and women: 34.0-45%, or presence of abnormal blood chemicals (hemoglobin S or Sickle Cell Trait)
  • Any history of malignancy
  • Personal or family history of blood clots
  • Abnormal prothrombin time/partial thromboplastin time (PT/PTT) test or problems with blood clotting
  • History of thromboembolic disease, hypertension, and known risk factors of cardiovascular disease
  • Blood donation within 8 weeks of beginning the study
  • History of seizures
  • History of inflammatory bowel disease
  • Any recent (within 4-6 weeks) and or expected history of prolonged periods of immobility or limited activity (including recent or upcoming surgery)
  • No evidence of iron deficiency (ferritin < 45 ng/ml)
  • Smokers or tobacco/nicotine (unless quit > 1 month prior to study orientation)
  • History of asthma
  • Experience recent (< 1 month of starting the study) cold, coughs, or respiratory tract infections
  • Allergy to skin adhesive
  • Known allergy to sulfa drugs
  • Evidence of apnea or sleeping disorder
  • Present condition of alcoholism, use of anabolic steroids, other substance abuse issues
  • Inability to tolerate iron supplement

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Acetazolamide
Acetazolamide (orally) 250 mg twice a day for 3 1/2 days.
Drug: Acetazolamide
Carbonic Anhydrase Inhibitor
Other Names:
  • Diamox
Experimental: Erythropoietin and Acetazolamide
Erythropoietin (subcutaneously) 50 IU /kg three times a week for 4 weeks. After the 4 week Erythropoietin, acetazolamide (orally) 250 mg twice a day for 3 1/2 days.
Drug: Acetazolamide
Carbonic Anhydrase Inhibitor
Other Names:
  • Diamox
Drug: Erythropoietin
Hormone for red blood cell
Other Names:
  • Procrit

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
3.2 km self-paced treadmill time trial performance
Time Frame: 35 minutes
Time to complete self-paced 3.2 km treadmill time trial (min:sec)
35 minutes

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
VO2peak
Time Frame: 30 minutes
Peak aerobic capacity will be assessed using a metabolic cart.
30 minutes
Lake Louise Acute Mountain Sickness Score
Time Frame: 10 minutes
Acute mountain sickness and severity will be assessed using the Lake Louise acute mountain sickness questionnaire. This Likert scale assess acute mountain sickness with scores ranging from 0 to 12. Zero indicates no acute mountain sickness and 12 indicates severe acute mountain sickness.
10 minutes
Ventilation rate
Time Frame: 20 minutes
Ventilation rate will be assessed using a pneumotachometer.
20 minutes
Percent body fat
Time Frame: 10 minutes
Percent body fat will be assessed using Dual Energy X-ray Absorptiometry.
10 minutes
Oxygen Saturation
Time Frame: 35 minutes
Oxygen saturation will be assessed using a finger pulse oximeter.
35 minutes
Erythropoietin
Time Frame: 4 hours
Erythropoietin will be assessed using an ELISA.
4 hours
Hematocrit
Time Frame: 5 minutes
Hematocrit will be assessed using manual hematocrit method.
5 minutes
Reticulocyte
Time Frame: 2 hours
Reticulocyte will be assessed using a hematology analyzer.
2 hours
Ferritin
Time Frame: 2 hours
Ferritin will be assessed using an ELISA.
2 hours
C-reactive protein
Time Frame: 2 hours
C-reactive protein will be assessed using an ELISA.
2 hours
Soluble transferrin
Time Frame: 2 hours
Soluble transferrin will be assessed using an ELISA.
2 hours
Arterialized capillary PO2
Time Frame: 5 minutes
Arterialized capillary PO2 will be assessed using a blood gas analyzer.
5 minutes
Arterialized capillary PCO2
Time Frame: 5 minutes
Arterialized capillary PCO2 will be assessed using a blood gas analyzer.
5 minutes
Arterialized capillary pH
Time Frame: 5 minutes
Arterialized capillary pH will be assessed using a blood gas analyzer.
5 minutes
Hbmass
Time Frame: 20 minutes
Hbmass will be assessed using the CO-rebreathing procedure.
20 minutes
Muscle tissue oxygenation
Time Frame: 35 minutes
Muscle tissue oxygenation will be assessed using a non-invasive near-infrared spectroscopy.
35 minutes
Lung Diffusion of carbon monoxide
Time Frame: 35 minutes
Lung Diffusion of carbon monoxide will be assessed using a spirometer.
35 minutes

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
United States Army Research Institute of Environmental Medicine

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
University of Puget Sound

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Roy Salgado, PhD, United States Army Research Institute of Environmental Medicine

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 27, 2022

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 30, 2023

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 30, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 17, 2022

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 28, 2022

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 29, 2022

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 26, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 25, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 21-06HC (M-10910)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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