ALTITUDE PROPHYLAXIS
What a controversial topic !!! Also one that has a lot of cultural variation. Europeans for example shy away from it as they think it reflects a non purist approach to climbing. Obviously this is a personal choice. We discuss drugs and altitude related disease extensively in our altitude medicine workshops. However, I can state my personal view based on extensive review of the literature.
DIAMOX (acetazolamide )works and accelerates acclimatisation. 125mg bd started ~ 24/24 before the ascent is as effective as higher doses with less risk of side effects. In Australia you can only get 250mg tablets but they are scored and can be cut in half easily. Note though that Diamox does not stop you getting acute mountain sickness (AMS) but rather statistically decreases the incidence of AMS. In other words just because you are using it does not mean you will necessarily be protected. Individual variation to responses to altitude and to Diamox are quite marked. It also dramatically improves breathing patterns during sleep which is important in helping you achieve rest on any big mountain. Whilst Diamox is an effective prophylaxis for AMS and also High Altitude Cerebral Oedema (HACE) it does not protect against High Altitude Pulmonary Edema (HAPE) - for that you need a pulmonary vasodilator such as Nifedipine.
However, there is one thing that is vastly better than any medications in helping get you up big mountains - and that is your acclimitisation schedule. The best strategy you can have is to ascend slowly once you reach 2500m at no more than an additional 300-500m per day. Throw in a rest day every 3rd or 4th day and try to sleep lower at night than the highest point you achieved on any given day and you will be well on the way to maximising your chance of success. Most people who fail on mountains such as "Kili" or routes such as the Inca Trail do so mainly because they try to do too much too quickly.