I started using Diamox when I started my 7 summits solo project. With attempts often from either Low Camps or Base Camps, I was attempting solos that often involved 2,000 meters or more of elevation gain in a day or less.
Final steps to the top of the world.
The standard dosage was 250 mg twice a day at the time – with the tingling, strong diuretic effect and making beer taste strange.
In Anchorage I met and stayed at Dr. Peter Hackett’s house at the time. His many years of high altitude research on Denali and establishing the high altitude clinic in Pheriche, Nepal, have continued to this day and he is widely considered one of the worlds’ foremost authorities on altitude. The fact he is a very talented climber and ascended Everest, virtually solo and without ropes from the South Col in 1981, also makes his perspective particularly invaluable to his fellow high altitude climbers.
In Anchorage before I soloed Denali, Dr. Hackett advocated for a far lower dosage, 1/4 of a standard tablet, or 62.5 mg, morning and evening. If you start a few days in advance, so much the better.
I tried it on Denali, soloing the Messner Couloir from 14.2 to the summit in 9 hours, and it certainly seemed to work. Two days later Joe Blackburn and I returned to the summit from 14.2 along the West Buttress, with little ill effects and Joe climbing quickly having had no previous ascent above 14.2. Everyone is different, but it also seems a touch of Diamox didn’t hurt.
Then on Vinson and later on Everest I found that even with ascents of 2,000 or even 3,000 meters, it made a difference, helping minimize the incidences of headaches, nausea and overall malaise common. And should the occasion arise, the beer tasted rather good still.
This dosage was further supported with a number of groups of up to 15 people I led to Tibet, and up to Everest Base Camp, where the choice was foul food or simply going to our own Base Camp and food quickly. Then on climbs, from fast ascents of Mont Blanc from the Chanomix Valley to ascents of new routes on Vinson with 2000 meters or more of elevation gain it again seemed to help across many teams and expeditions.
In groups where some didn’t take Diamox, almost universally they suffered altitude symptoms and were then treating themselves with repeated doses of painkillers, feeling nauseous, and experiencing fatigue and generally feeling lousy.
I have had the good fortune to catch up with Dr. Hackett, at lectures we shared at the Smithsonian, at an American Mountain Guides High Altitude Symposium where he led a specialized high altitude clinic for Guides and when he returned to his roots in 2010 and managed the Everest Base Camp clinic, where the 1/4 tab (or less) he commented, is still valid.
In further communications on 8 March, 2019 with Dr. Hackett, he cited just released research that specifically supported the 62.5 dosage.
This was also highlighted in further in an article in 2019, still not as large a sample group as would be ideal, but supporting the reduced dosage. Interesting, they didn’t find any lessening of side effects from the 125 to 62.5 dosage – something I personally find are further alleviated at the lower dose. One would logically think these would decrease – but I’d err on the side of the data and individuals own experience here.
Dr. Hackett also commented that some people may see Diamox as an aid or form of doping, while in reality it is the opposite and will actually marginally decrease max. exercise performance – not relevant to trekkers and climbers who don’t operate anywhere near their max. “If anyone thinks it is a performance enhancing medication, it is not!”
As I walked up the Khumbu to Everest Base Camp with Peter Hillary this year, I saw people on everything from 250 mg, twice a day, to people who said their Doctors said taking Diamox would mask their altitude symptoms.
In my experience, 250mg produces dieresis to the point you spend the night up peeing and the days desperately trying to rehydrate. And not taking any, means you must go slower, or feel worse and then take other medications.
Whether people consider this an acceptable aid or not, is entirely up to them. As Peter Hillary commented today when we talked of our Everest climbs, the one consistent element is it is ‘painful’. Perhaps making altitude a bit less painful and the heights a bit more enjoyable is okay?
This protocol is for taking Diamox as prophylaxis, in advance of going to altitude and then when ascending. If developing AMS, the dosage still remains at 125 or 250 mg when indicated and then twice a day thereafter.
Perhaps pain and suffering is an important part of altitude, but I’d rather wake up and feel like running up the trail than hiding under the covers which I fear would be the alternative.
Our group of 18 headed up to Everest Base Camp in 2019, where we check pulse, oxygen saturation and score on the Lake Louise chart each day are so far all doing very well as we ascend toward Everest Base Camp.
I am absolutely not a Dr., don’t prescribe Diamox and all who travel with me make their own choices. A safe protocol is certainly not ascending 1,000 meters or more a day in any case, and on our current trek with The Mountain Company we do no more than 300 meters a day of vertical, with a good rest every 1000 metres of ascent.
Dr. Hackett, in his latest communication also commented the the sulfa allergy we have always watched out for is no longer applicable.
“A new consensus, based on data, is that persons allergic to sulfa antibiotics do not need to avoid Diamox, which is a different kind of “sulfa” drug.”
If I can help add to a mountain experience, to see a sunrise over Everest without a splitting headache or enjoy a full bowl of Sherpa stew at Gorak Shep, perhaps this protocol is something you may consider after discussions with your Doctor.