Chances are that the Z-Pac caused some problems; it's also possible that the IV antibiotic they gave you also caused problems. As you probably already know, many antibiotics are contra-indicated with ANY form of MG.

I know when I was in the hospital in December (for totally unrelated problem), the doctors were trying to get my blood pressure lower, so they gave me a beta-blocker. BIG mistake.....

If it doesn't get better in a little while, I'd be concerned; right now it might just be your body trying to get the medications out of all of the nooks and crannies -