Just to add to kcjd's post... yes, AC is considered malarial and does prohibit you from donating whole blood, but it does not stop you from donating plasma or platelets (which you can do more often anyway).
This is the info I have from the local organization I use (Bloodsource), and since I travel to various spots, I've been deferred from donating whole blood... this way I can still donate. For example, I went to Panama and was on a ship the entire time, but because we went to the San Blas Islands and got off the boat, I couldn't give whole blood, but plasma was fine.
Donations are down, so if you can, consider donating. You won't miss what you give up...and you could be saving a life!
