Effect of Acetazolamide and Gingko Biloba on the Human Pulmonary Vascular Response to an Acute Altitude Ascent

Acetazolamide and gingko biloba are the two most investigated drugs for the prevention of acute mountain sickness (AMS). Evidence suggests that they may also reduce pulmonary artery systolic pressure (PASP). To investigate whether these two drugs for AMS prevention also reduce PASP with rapid airlift ascent to high altitude, a randomized controlled trial was conducted on 28 healthy young men with acetazolamide (125mg bid), gingko biloba (120mg bid), or placebo for 3 days prior to airlift ascent (397m) and for the first 3 days at high altitude (3658m). PASP, AMS, arterial oxygen saturation (Sao(2)), mean arterial pressure (MAP), heart rate (HR), forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and peak expiratory flow (PEF) were assessed both at 397m and 3658m. HR, PEF, and PASP increased with altitude exposure (p<0.05), and SaO(2) decreased (p<0.05). PASP with acetazolamide (mean at 3658m, 26.2mm Hg; incremental change, 4.7mm Hg, 95% CI., 2.6-6.9mm Hg) was lower than that with ginkgo biloba (mean at 3658m, 33.7mm Hg, p=0.001; incremental change, 13.1mm Hg, 95%CI., 9.6-16.5mm Hg, p=0.002), and with placebo (mean at 3658m, 34.7mm Hg, p<0.001; 14.4mm Hg, 95% CI., 8.8-20.0mm Hg, p=0.001). The data show that a low prophylactic dosage of acetazolamide, but not gingko biloba, mitigates the early increase of PASP in a quick ascent profile.