Wilderness Medical Society has just rolled out the second update of the evidence based guidelines for prevention & treatment of AMS , HAPE & HACE. This was from the start in 2010 a gold standard document from a highly experienced expert panel . The references now lists more than a hundred sources.
Selected keypoints :
Lowest level for altitude sickness : mentioning the possibility of AMS below 2500 in the extra sensitive group . This was first mentioned in the 2014 update.
Medication : preventive use of Acetazolamide/Diamox to be “strongly considered” for moderate & high risk category. This starts with all first comers and no history of AMS going higher than 2800 meters first night . One small study in 2019 claiming to prove equal effect & equal level of side effects from half dosage ( 62 vs 125 mg x 2 ) reason for more research.
Dexamethason : prevents AMS , but does not ( as opposed to Diamox ) speed acclimatization . Risks with long time use , not to be stopped abruptly , not for children.
Ibuprofen : limited and conflicting evidence , can be taken by those who are unwilling to take acetazolamide or dexamethason.
Ginkgo boloba : conflicting evidence , Diamox considered “far superior”. Not to be used when pregnant or while taking anticoagulants.
Hypoxic tents ( basically a backwards version of Gamow bags : oxygen generator run inside a sealed tent , shunting O2 to the outside ) has a positive effect , given long enough period : nightly for weeks.
Other options : no preventive effect from coca , iron supplements , ASA/Aspirin , or high intake of water . Avoid dehydration.