No, I agree brain swelling is not funny. I just don’t understand the notion of taking a drug that has potential side effects, just in case you might develop altitude sickness. In the 10 years that I have run the race and been part of the Colorado Springs running community, I am not aware of any cases of cerebral edema during the PPA or PPM. Just to be clear, not everyone who comes from sea level experiences altitude sickness. Some runners show up here the day before, run their race, do awesome and leave. Not everyone who lives and trains here is immune from it either. But in the scheme of think, only a small percentage of people will even suffer true altitude sickness and very few required medical attention. In this race it is very hard to determine whether your symptoms are cause by the altitude, dehydration or sheer exhaustion. Each one of these can, in extreme cases, kill you. In 2005 when 750 runners were stuck on top of the mountain for hours because of weather, no one developed brain swelling. People were feeling shitty and were vomiting, but no one was in critical condition. If you read this message board and follow the repetitive advice of acclimate, take it easy on the bottom, fuel and drink lots of fluids, you should know everything crucial. Is there a guarantee? No, but that is true for all of the runners including the elites.