Unless the antibiotic kills the bacterial infection and the swelling in your Eustachian tube goes down and opens, the altitude will show you real pain.
Rod is right...think those screaming kids on airplanes when you descend and the increasing air pressure blows their ears inward.
I can also tell you that just driving up and down the Sierras can be excruciating. It hurt so bad when I had a ear infection in the Sierras once, I took 4 or 5 kiddie antihistamine /decongestants and got so loopy I fell down the steps in Reno on the way home.
