I started taking the Z-pack two weeks ago and the only side effec...

I started taking the Z-pack two weeks ago and the only side effect that I had was that I was very tired and I got a headache but that went away, then I went back to my doctor today and with the same symptoms from two weeks ago and they re prescribed me with Z-pac for my upper respiratory infection and I took the first two with food and now I have diarrhea and a little bit of nausea but nothing to severe. I will be taking the other one tomorrow and I will keep you guys posted on how I feel