Effects of Iloprost on Hypoxic Pulmonary Vasoconstriction at Altitude

Loma Linda University (LLU)

Status and phase: Withdrawn; Phase 1

Conditions: Hypoxic Pulmonary Vasoconstriction

Treatments: Drug: iloprost

Study type: Interventional

Funder types: Other

Identifiers

NCT00724321

58205

Details and patient eligibility

About

The objective of this study is to determine if single dose administration of inhaled iloprost will reduce pulmonary artery pressure, reduce hypoxic pulmonary vasoconstriction and improve arterial oxygenation at rest and during exercise at high altitude.

Full description

Three major pathways in addition to oxygen modulate pulmonary vascular tone: 1) nitric oxide, 2) endothelin, and 3) prostacyclin. Considerable animal data support the role of the prostacyclin pathway in modulating hypoxic pulmonary vasoconstriction. In humans, prostacyclin and its analogs are important therapeutic agents in the treatment of pulmonary arterial hypertension (PAH). Despite the animal data and human data in PAH there is very little information about the use of to relieve hypoxic pulmonary vasoconstriction in healthy humans. Inhaled iloprost is an ideal agent to study the prostacyclin pathway due to its short duration of action (30-90 min) and elimination half-life of only 20-30 min. Individuals already participating in the Nepal Medex 2008 trip will be invited to participate in this research. Participants will be healthy active females or males, between 18-80 years of age, without known pregnancy or liver disease, who have a readily measurable tricuspid regurgitant velocity by Doppler echocardiography. If possible, we will attempt to identify a cohort of HAPE susceptible patients. Participants will undergo evaluation both at sea level (baseline) and at high altitude. Baseline (low altitude) testing will be performed in Bangor, North Wales, UK, and will include evaluation of pulmonary artery systolic pressures, cardiac output, and oxygen saturation at rest and during submaximal exercise before and after inhalation of iloprost. This strategy will then be repeated at an altitude of approximately 5000 meters in the Dhaulagiri region of Nepal.

Sex: All

Ages: 18 to 80 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

1. Age: 18 - 80 years
2. Healthy physically active males or females
3. Have readily measurable tricuspid regurgitation (TR) peak systolic velocity by continuous wave Doppler ultrasound

Exclusion criteria

1. Known liver disease
2. Pregnancy
3. Medications that in the opinion of the investigators could place subjects at increased risk of complications Any other medical condition that in the opinion of the investigators would place the subject at high risk

Trial design

Primary purpose: Basic Science

Allocation: N/A

Interventional model: Single Group Assignment

Masking: Triple Blind

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0 participants in 1 patient group

Iloprost and placebo

Other group

Description:

Each participant will undergo testing at sea level and altitude after inhalation of iloprost and placebo, sequence is randomly assigned.

Treatment:

Drug: iloprost