Glucosamine can come with some unneeded fillers, so when choosing a brand, read the labels and use those with less filling material.
I like Glucosamine Sulfate as it works better *for me* than anything else.
Here is some pretty cool info on altitude related issues. http://www.altitudemedicine.org/index.php/altitude-medicine/learn-about-altitude-sickness
Here is some info on how diamox (it's a carbonic anhydrase inhibitor) works. http://www.netdoctor.co.uk/seniors-health/medicines/diamox.html
If you scroll down here, you can see how carbonic anhydrase inhibitors work. http://www.flashcardmachine.com/clinical-pharmacology1.html To summarize, they displace a Hydrogen Ion, which is thought to be responsible for increased sensation in pain, and, perhaps more importantly for hunters/outdoorsmen...will inhibit the ability of hemoglobin to carry oxygen. So, the job of diamox/CA inhibitors is to chemically allow hemoglobin to carry more oxygen, thus helping to eliminate some of the symptoms of altitude issues.
If you are out of diamox...or just don't have any...some alka seltzer, or baking soda, may just do the trick because they each contain sodium bicarbonate. But, as Wade indicated, there may be issues with any drug you take. And yea, it does work. BUT, you will need to increase your uptake of water as well...some of the symptoms *can* include the runs or some other form of GI distress. Sodium bicarbonate works to (chemically) displace the Hydrogen Ion and free up Hemoglobin's ability to carry O2 to working tissues.