Vesicoureteral reflux, UTI, Suprax treatment and possible side effects

Patient: My two and a half year old daughter has vesicoureteral reflux and recently had a urinary tract infection. She was given Suprax to treat it and we have a few more days to go on the dosing. Everything was going fine until a few days ago when she refused to eat or drink anything. She still won’t eat or drink anything and is throwing wicked tantrums about food or drink and is very irritable. We’re unsure if maybe this is a side effect from the medication or something else. This is not her typical behavior. She has tantrums but nothing like this. Should we be worried?