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Roncin J.P., Schwartz F., D’Arbigny P. EGB 761 in control of acute mountain sickess and vascular reactivity to cold exposure. Aviat Space Environ Med. 1996; 67: 445-452. Participants: 44 healthy subjects who had previously experienced AMS Study Design: Randomized parallel study Objective: To determine if ginkgo has a preventative effect on AMS, as well as to determine vasomotor changes of extremities during a 3-day Himalayan trip. Treatment: Twenty-two participants received ginkgo 80mg BID, and 22 participants received placebo. Assessment criterion: Based on the Environmental Symptoms Questionnaire (ESQ-III), which consists of 67 items on a 6-point scale. Symptoms include aching in legs, feet, shoulders, arms and hands, coldness in hands or feet, numbness, feeling sick, decreased diuresis, headache, insomnia, vertigo, nausea, and dyspnea. Participants filled this questionnaire out daily during the ascent to base camp, which took 8 days, 3 days after, and then on days 17, 20, 21 and 23. Results: Primary results included both cerebral and respiratory AMS. None of the ginkgo users experienced cerebral AMS, while 4% of the placebo users did. Fourteen percent of ginkgo users experienced respiratory AMS, while 82% of placebo users did. Secondary results measured functional disability, such as paraesthesias, pain, numbness, stiffness or swelling of hands. Ginkgo users saw a 23% improvement in the cold gradient, while placebo users experienced a 10.4% deterioration. Conclusion: Ginkgo is a useful treatment for the prevention of AMS. It is well tolerated with no adverse effects, and it decreases vasomotor disorders of the extremities. Study limitations: It is not a double blind design and small power.
Maakestad K., Leadbetter G., Olson S., Hackett P. Ginkgo biloba reduces incidence and severity of Acute Mountain Sickness. Wilderness and Environmental Medicine. 2000;12: 49-56. Participants: 40 college students who lived at 1400m above sea level. Design: A randomized, double-blind, placebo-controlled study. The participants were matched for gender, age and rate of ascent. Objective: To determine if prophylactic ginkgo given can affect the incidence and severity of AMS during a rapid ascent (2-hour car ride) and overnight stay to Pike’s Peak. Treatment: Ginkgo 120mg PO BID (n=21) or placebo (n=19), starting 5 days prior to ascent and continuing at the altitude Assessment: An ESQ-III >0.7 or Lake Louise Score (LSS) > 3 was indicative of AMS. Results: Seven on Ginkgo and 13 on the placebo suffered from AMS (p<0.2). The mean LLS was 3.9+/- 0.6 for ginkgo, and 6.2 +/- 0.9 for placebo. The ESQ-III was 0.77 +/- 0.2 on ginkgo, and 1.59 +/- 0.32 for placebo. Conclusion: Ginkgo taken 5 days prior to a rapid ascent of 4300m decreases both the incidence and severity of AMS. Study limitations: Small power.
Gertsch J.H., Seto T.B., Mor J., et al. Ginkgo biloba for the prevention of severe acute mountain sickness starting one day before rapid ascent. High Alt Med Biol. 2002; 3:29-37. Participants: 26 individuals who reside at sea level Design: A randomized, double-blind, placebo-controlled study. Participants were matched for gender, age and race. Objective: To determine if ginkgo is an effective prophylactic agent if begun 1 day prior to rapid ascent of Mauna Kea, Hawaii Treatment: Ginkgo 60mg PO TID (n=12) or placebo (n=14) Assessment: LLS measured at baseline, 2835m, and after 4 hours at 4205m. A LLS greater or equal to 3 with headache was indicative of AMS. Results: The LLS at 4205m for ginkgo users was 4 (range 1-8), while for the placebo users it was 5 (range 2-9) (p=0.03). Seventeen-percent of ginkgo users (n=2) and 64% of placebo users (n=9) developed severe AMS (p=0.021). Eventually, though, 21 out of the 26 participants developed AMS (81%) Conclusion: One day of pretreatment with ginkgo 60mg TID significantly reduces the severity of AMS prior to rapid ascent to 4205m from sea level. Study limitations: Ginkgo use was not statistically significant and small power.
Gertsch J.H., Basnyat B., Johnson E.W., Onopa J., Holck PS. Randomized, double blind, placebo controlled comparison of ginkgo biloba and acetazolamide for prevention of acute mountain sickness among Himalayan trekkers: the prevention of high altitude illness trial (PHAIT). BMJ. 2004; 328:797. Participants: 614 healthy western trekkers Design: A randomized, double-blind, placebo controlled study Objective: To evaluate the efficacy of ginkgo, acetazolamide, and their combination as a prophylaxis against AMS during an approach to Mount Everest base camp Treatment: Trekkers received either ginkgo, acetazolamide, placebo, or a combination of ginkgo and acetazolamide. Assessment: LLS score greater than or equal to 3 with headache and one other symptom (nausea, vomiting, fatigue, dizziness or difficulty sleeping). Secondary outcome measures included blood oxygen content, severity of syndrom (LLS>5), incidence and severity of headache. Results: Participants in the acetazolamide group showed high levels of protection from AMS, while ginkgo and placebo did not. The incidence of AMS was 34% for placebo, 12% for acetazolamide, 35% for ginkgo, and 14% for combined ginkgo and acetazolamide. Participants with increased severity of AMS included 18% for placebo, 3% for acetazolamide, 18% for ginkgo, and 7% for combined ginkgo and acetazolamide. Conclusion: When compared with placebo, ginkgo is not as effective at preventing acute mountain sickness as acetazolamide 250mg BID.
Chow T., Brown V., Heileson H.L., Wallace D., Anholm J., Green S.M. Ginkgo biloba and Acetazolamide Prophylaxis for Acute Mountain Sickness. Arch Intern Med. 2005; 165:296-301. Participants: 57 unacclimatized individuals Design: A randomized, double-blind, placebo controlled study. Objective: To compare the effectiveness of ginkgo and acetazolamide for AMS prophylaxis. Treatment: Ginkgo (n=17), acetazolamide (n=20) and placebo (n=20) Assessment: LLS greater than or equal to 3 with a headache indicated AMS. Results: The LLS score for acetazolamide was significantly lower than placebo group, unlike the ginko group. The incidence of AMS was less in the acetazolamide group as compared with the placebo group. The frequency of occurrence was similar between the ginkgo and placebo groups. Conclusion: Prophylactic acetazolamide therapy decreases AMS symptoms and incidence, while ginkgo did neither.Study limitations: Small power. |