My Six year old daughter is on this med and she has had no side a...

My Six year old daughter is on this med and she has had no side affects that I can tell. She is having a more trouble focusing on school (I home school) and seems tired, but I am not sure that that is the meds. Someone on this comment page said there is sulfer in it. Is that true, if so is that why people are having reactions if the are allergic to sulfer? anyway I really cam online to see if I had to refrigerate this antibiotic, I keep forgetting to give her the second dose so I was going to try and keep it where I could see it. Thank you for your help.