I didn't get side effects from Vidaza until the 4th day in every cycle and right now I can't remember how long they would last, but the skin reaction was immediate from the shots and after few days of trying they switched it to the IV form. Much better!
Remember to take zofran an hour before, but even if you forget to take it before, just take it after, the nausea symptoms are not immediate. You should keep a diary or a log of your side effect symptoms to discuss with the doctor, as there are other alternatives if it doesn't help out.
I gained maybe 10 lbs in fluids while in the hospital, then after few months at home started losing weight. Now, 11 months later I am 35 lbs lighter, and have maintained the same weight +/- 5 lbs.
Stay active, go for little walks, lift little weights everyday now and your recovery after transplant might be easier. But also give yourself a break!
Hang in there!! All the best
Tii - MDS (11mo old, post BMT)