野外與登山醫學-犀利士 tadalafil 和 類固醇~地塞米松 dexamethasone 都可以降低 HAPE 機率 (2006年)

http://www.ncbi.nlm.nih.gov/pubmed/17015867

(備註 2014 WMS 指引, 類固醇不建議單獨用於預防 HAPE. HAPE 如果需藥物預防, 首選還是 nifedipine)
(類固醇預防HAPE研究目前仍很缺乏, 數量太少)

這篇是 2003 年的實驗. 在 2006 年發表於內科醫學雜誌. 

在29名先前曾經發生過 HAPE 的成人. 分成三組. 預防性吃藥. 一組吃  tadalafil (10 mg) 一天兩次, 一組吃 dexamethasone (8 mg) 一天兩次, 一組吃安慰劑一天兩次, 從海拔 490 公尺上升至海拔 4559 公尺, 待兩天.  

Both tadalafil and dexamethasone may reduce the incidence of high-altitude pulmonary edema: a randomized trial.
Ann Intern Med. 2006; 145(7):497-506 (ISSN: 1539-3704)

Maggiorini M; Brunner-La Rocca HP; Peth S; Fischler M; Böhm T; Bernheim A; Kiencke S; Bloch KE; Dehnert C; Naeije R; Lehmann T; Bärtsch P; Mairbäurl H
University Hospital Zürich, Zürich, Switzerland; Université de Bruxelles, Brussels, Belgium. klinmax@usz.unizh.ch

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.

吃犀利士的一組共 10 人, 兩名在海拔 4559 公尺發生嚴重 AMS,. 從實驗退出. 但這兩位沒有發生 HAPE. 其他 8 個人有一個發生HAPE. 7 名發生 AMS. 

吃安慰劑的九個人, 有七個人發生 HAPE. 8名發生 AMS.

吃 dexamethasone 的10 個人, 沒有人發生 HAPE. 3 名發生 AMS. 

吃犀利士和 dexamethasone 的兩組. 肺動脈壓力比較低. (肺動脈高壓是 HAPE 成因)  

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.