Im sorry to hear about your daughter.
Prevacid or lansoprazole is actually a good drug to control the symptoms of acid reflux and i can understand your concerns about giving this your daughter. However lansoprazole is one of the safest drugs on the market, there are certain side effects with the drug but they a few and far in between. The most common side effects of this drug are,
The less common side effects which can occur are,
Now there are other side effects but they are very rare and dont occur usually in many patients. Some of them have an incidence of less than 1%.
Now that was about the safety of the drug, regarding as to how long she should be taking it, it depends on the symptoms or rather the severity of the symptoms. Usually for the first time, the drug is used for 2 weeks but some doctors like to extend that treatment period for upto a month depending on the response of the drug. Since your doctor seems to be improving, i would suggest that you talk to her doctor about stopping the drug now. When she has to stop the drug, she can simply stop it without tapering it off as there shouldnt be any harmful symptoms if she comes off it suddenly.
Now if the symptoms reappear after stopping the drug then that could be an indication of getting an endoscopy done which will determine what is the actual cause of the reflux. Secondly its possible that she could have a h.pyroli infection in the stomach which is causing the symptoms which would need a urea breath test and stool antigen test to be confirmed.
I would recommend that you discuss stopping the drug with her doctor and see if that causes here symptoms to reappear if they do, then consider an endoscopy.
I hope I have been helpful and this answers your query. Please remember to assign a feedback rating so JA will compensate me for my time. You are free to ask follow-up questions thereafter at no charge although any bonuses would be appreciated. Please allow up to 24 hours for a follow-up response if I am signed off.
If, for some reason, you are not satisfied with the answer, I would appreciate knowing why so that I can try to clear up any misunderstanding that may have taken place and still earn a positive rating from you. Finally, you may request me in the future by beginning the question with "THIS IS FOR Dr. Muneeb Ali".
Thank you for using Just Answer.