Display Settings:

Format

Send to:

Choose Destination
Ann Intern Med. 2006 Oct 3;145(7):497-506.

Both tadalafil and dexamethasone may reduce the incidence of high-altitude pulmonary edema: a randomized trial.

Author information

  • 1University Hospital Zürich, Zürich, Switzerland; Université de Bruxelles, Brussels, Belgium. klinmax@usz.unizh.ch

Abstract

BACKGROUND:

High-altitude pulmonary edema (HAPE) is caused by exaggerated hypoxic pulmonary vasoconstriction associated with decreased bioavailability of nitric oxide in the lungs and by impaired reabsorption of alveolar fluid.

OBJECTIVE:

To investigate whether dexamethasone or tadalafil reduces the incidence of HAPE and acute mountain sickness (AMS) in adults with a history of HAPE.

DESIGN:

Randomized, double-blind, placebo-controlled study performed in summer 2003.

SETTING:

Ascent from 490 m within 24 hours and stay for 2 nights at 4559 m.

PATIENTS:

29 adults with previous HAPE.

INTERVENTION:

Prophylactic tadalafil (10 mg), dexamethasone (8 mg), or placebo twice daily during ascent and stay at 4559 m.

MEASUREMENTS:

Chest radiography was used to diagnose HAPE. A Lake Louise score greater than 4 defined AMS. Systolic pulmonary artery pressure was measured by using Doppler echocardiography, and nasal potentials were measured as a surrogate marker of alveolar sodium transport.

RESULTS:

Two participants who received tadalafil developed severe AMS on arrival at 4559 m and withdrew from the study; they did not have HAPE at that time. High-altitude pulmonary edema developed in 7 of 9 participants receiving placebo and 1 of the remaining 8 participants receiving tadalafil but in none of the 10 participants receiving dexamethasone (P = 0.007 for tadalafil vs. placebo; P < 0.001 for dexamethasone vs. placebo). Eight of 9 participants receiving placebo, 7 of 10 receiving tadalafil, and 3 of 10 receiving dexamethasone had AMS (P = 1.0 for tadalafil vs. placebo; P = 0.020 for dexamethasone vs. placebo). At high altitude, systolic pulmonary artery pressure increased less in participants receiving dexamethasone (16 mm Hg [95% CI, 9 to 23 mm Hg]) and tadalafil (13 mm Hg [CI, 6 to 20 mm Hg]) than in those receiving placebo (28 mm Hg [CI, 20 to 36 mm Hg]) (P = 0.005 for tadalafil vs. placebo; P = 0.012 for dexamethasone vs. placebo). No statistically significant difference between groups was found in change in nasal potentials and expression of leukocyte sodium transport protein messenger RNA.

LIMITATIONS:

The study involved a small sample of adults with a history of HAPE.

CONCLUSIONS:

Both dexamethasone and tadalafil decrease systolic pulmonary artery pressure and may reduce the incidence of HAPE in adults with a history of HAPE. Dexamethasone prophylaxis may also reduce the incidence of AMS in these adults. ClinicalTrials.gov identifier: NCT00274430.

Comment in

PMID:
17015867
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Silverchair Information Systems
    Loading ...
    Write to the Help Desk