There is a difference of opinion. However, if you have not been to high altitude often, we suggest you consider trying Diamox. You may wish to start with one half of a tablet in Kathmandu to see how you react to the medication and if you have any side effects. During the approach to basecamp we suggest you consider taking one to two tablets per day, depending upon your body weight, rate of ascent, and your reaction to the medication.
We encourage members who are going to high-altitude for their first time to try Diamox. During our trek, we can often tell which team members are using Diamox and which are not according to their level of activity vs. lethargy. Those trying Diamox are often seen laughing, playing cards, and throwing frisbees in camp, while those who are not are often seen hunched over their tea in the dining tent, holding their heads and grumbling about a headache. The non-users may also not be seen at all, as they are in their tent lying in their sleeping bag suffering a migraine-like headache.
Whatever your opinion is, Diamox is a very vital part of any high altitude climbers medical kit, used in the prevention of mountain sickness, also known as high altitude sickness or acute mountain sickness (AMS). It's a very old drug, originally developed for cardiac patients in the 1930s. It is the most well known and tested of all of the high altitude drugs. It works well as a preventative medication, taken in advance of symptoms, proactively. It also works acutely in first-aid situations to reduce the severity of symptoms once high-altitude sickness ensues. Common dosage is a half tablet (tablets are 250mg) before AMS occurs, to see if any severe side effects occur. Common side effects include tingling, 'pins and needles' and excessive urination. If no severe side effects occur, it's common to take one 250 mg tablet per day. Up to 2 or even three tablets may be taken per day, depending upon body weight (smaller people need to take less, and larger people more). Be sure to drink enough water, as Diamox is a diuretic (increases urination and thus dehydration).
Diamox increases your body's uptake of carbon dioxide through a ph change in the blood, so as an indirect reaction of your body, it causes you to breath (exhale) more to get rid of the extra CO2. The other mechanism your body uses to get rid of extra CO2 is to urinate more. Breathing more causes you not only to exhale more CO2, but also to take in more oxygen. Your body responds to all of this fresh new oxygen by making your red blood cell count increase. This is what you need to become acclimatized to the higher altitude, more red blood cells to carry more oxygen. Whether you take Diamox or not, this red blood cell increase happens naturally as you slowly ascend to higher altitudes. Diamox just causes the red blood cells to multiply a little faster because you are breathing a bit more. Some people say you can do this yourself without taking Diamox, just hyperventilate all of the time!
