Thanks for the information on meds to help prevent altitude sickness. I may pursue this further and determine the chemical's site of action. Perhaps hemoglobin is involved in the story. If I find anything of interest, I'll report back.

Lisa: we have a great clinic at the UW Hospital that handles travelers' needs. I plan to head to Peru next year, so will be armed, I hope, with enough info to determine whether these meds are for me, after also weighing in with what my own physician says.

Joan Peterson in WI