Effect of Bosentan on Exercise Capacity at High Altitude

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00432978
Recruitment Status : Completed
First Posted : February 8, 2007
Last Update Posted : April 18, 2007
Information provided by:
VA Loma Linda Health Care System

Brief Summary:

This study is to determine whether bosentan will alter exercise capacity after rapid ascent to high altitude.

We hypothesize that bosentan administration will improve arterial oxygenation and exercise capacity.

Condition or disease Intervention/treatment Phase
Altitude Pulmonary Hypertension Drug: Bosentan administration Phase 1

Detailed Description:
Both the prostacyclin and the nitric oxide pathways are important in modulating hypoxic pulmonary vasoconstriction (HPV). There is little information about the role of the endothelin pathway at high altitude. The endothelin pathway involves the activation of two distinct receptors, A and B. Bosentan is a nonpeptide, specific, competitive, dual antagonist of both endothelin receptor subtypes. The primary objective of this study will be to determine the effect of endothelin receptor blockade with bosentan on exercise performance and HPV. This is a prospective, double blind, placebo-controlled, randomized cross-over study involving healthy subjects aged 25-55 years of age. Subjects will undergo echocardiography and exercise testing at low altitude (< 500m) and at 3800m. Subjects will receive either bosentan vs. placebo and will be studied at low and high altitude on two occasions in a crossover design. Primary outcome measures will be pulmonary artery systolic pressure measured by echo-Doppler and exercise capacity. A better understanding of the role of the endothelin pathway in HPV may lead to improved treatments for some patients.

Study Type : Interventional  (Clinical Trial)
Enrollment : 20 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double
Primary Purpose: Treatment
Official Title: Effect of Bosentan on Exercise Capacity at High Altitude
Study Start Date : July 2006
Actual Study Completion Date : February 2007

Resource links provided by the National Library of Medicine

Drug Information available for: Bosentan

Primary Outcome Measures :
  1. Exercise Capacity
  2. Pulmonary artery systolic pressure

Secondary Outcome Measures :
  1. Hemoglobin oxygen saturation

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 55 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Normal healthy subjects aged 18 - 55 years

Exclusion Criteria:

  • Pregnancy
  • Heart, lung or liver disease
  • Use of glyburide, cyclosporin A

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00432978

United States, California
VA Loma Linda Healthcare System
Loma Linda, California, United States, 92357
Sponsors and Collaborators
VA Loma Linda Health Care System
Principal Investigator: James D Anholm, MD VA Loma Linda Healthcare System
Principal Investigator: Katja Ruh, MD Loma Linda University

Publications automatically indexed to this study by Identifier (NCT Number): Identifier: NCT00432978     History of Changes
Other Study ID Numbers: 00534
Prom: 0030
First Posted: February 8, 2007    Key Record Dates
Last Update Posted: April 18, 2007
Last Verified: April 2007

Keywords provided by VA Loma Linda Health Care System:

Additional relevant MeSH terms:
Hypertension, Pulmonary
Lung Diseases
Respiratory Tract Diseases
Antihypertensive Agents
Endothelin Receptor Antagonists
Molecular Mechanisms of Pharmacological Action