Why can't my sister stop coughing/being sick?

It’s been a really crappy couple of months for her, but this is the gist of it. She has asthma and she’s allergic to sulfer. She takes levalbuterol as her usual inhanler medication. The only inhaler she had left was albuterol sulfate. I don’t know how or why they gave it to her, but it’s all she had to use. We got her a rescue inhaler by bugging the hell out of her doctor’s office for 4 hours. What are little sisters for, if not to be a pest? We got that inhaler, but she had to go to the emergency room anyways and there they gave a prescription for prednisone. That didn’t work. She went back to emergency room a few days later and then they gave her amoxicillin. That seemed to work. She went to her doctor’s office finally and they gave her omeprazole and told her to get a nebulizer. I know she hasn’t needed to use the nebulizer because she dosen’t need the medication that came with it. She has requested to amoxicillin but they refuse to give it to her even though that is the only thing that has worked so far.

We think it started with a small bout of food poisoning. I some way her stomach was irritated and then it went up towards her bronchioles. All we know now is that she can’t stop coughing. No matter what we try, it doesn’t stop. Does anyone have any medical advice or can shed some light on what is going on?

The only things that she is allergic to are sulfer and cat hair.