Diamox is brilliant – but how does it work?

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Diamox is brilliant – but how does it work?

June 5th, 2014|Advice|

Most of you who have climbed Kilimanjaro, or are shortly to do so, will be familiar with the ‘wonder drug’, Diamox. Originally invented as a treatment for the eye condition, galucoma, it was soon realised that the drug was also very beneficial in combatting the symptoms and underlying causes of altitude sickness.

I myself have seen the incredible results that Diamox can have on some people (and it’s worth noting here that it doesn’t work for everyone) who are suffering the effects of being at altitude. From being poor, aching, nauseous wretches one minute, often the sufferer will be leaping around 30 minutes later with all symptoms of altitude sickness – the headaches, nausea and, in some cases, ataxia – having been alleviated thanks to the consumption of one, small tablet of Diamox.

But how does the pill actually work? Well this is where Mr (or possibly Dr) Cliff Wener, comes in. Cliff contacted me this week regarding our write-up of Diamox on the website and in the book. In particular, he took issue with my phrase “Diamox works by acidifying the blood, which stimulates breathing, allowing a greater amount of oxygen to enter into the bloodstream.”

According to Cliff, Diamox actually works like this (and I am goingto quote him verbatim now, as a) I think he explains it very well; and b) if I interfered with his explanation, I might well introduce other errors into his work):

“As you ascend to higher altitudes, pressure decreases. The composition of air (21% Oxygen) remains constant but the number of O2 molecules inspired in each breath becomes less and less. The body reacts by increasing our breathing rate (ie hyperventilation) to try and get more O2. So far… easy to understand.

As we breathe faster, we exhale more and more CO2. the corresponding level of bicarbonate (used as a buffer by the body for CO2) remains constant. This causes our blood to become quite alkalinic – and bingo – onset of symptoms of Altitude Sickness.

Solution is get rid of that bicarbonate.

Diamox acts by instructing the kidneys to rapidly excrete that bicarbonate hence turning the blood acidic and compensates for the respiratory alkalosis. The rapid excretion of the bicarbonate is accomplished through more frequent urination and alleviation of symptoms.

Despite multiple mentions of the Internet that use of Diamox results in an increase in blood oxygenation, this is not true. Only way to do that is with an oxygen mask or Gamov bag.”

I am, of course, very grateful to Cliff Wener for this explanation, and for making us all feel slightly cleverer than we were before we’d read this – cheers Cliff!

About the Author:

I am a little obsessed with Mount Kilimanjaro. Since writing the first edition of the Kilimanjaro guide in 2001 I have climbed the mountain more than 30 times and occasionally leads treks up the mountain myself. And when I'm not in Tanzania researaching for the next edition of the guide (the fifth edition was published in 2018), I can be found living near Hastings, England, updating this website (which was first published in 2006), writing about the national trails of England, answering Kili-related emails and putting on weight.Friends describe me as living proof that virtually anybody can climb Kilimanjaro.