Hi Lissamonkey!You are taking Famotidine which is generic for Pepcid AC. You can read about Famotidine here. Dr Todd Eisner answers the question about how long it takes for acid medications to begin working in this question and answer sharepost question #2. Dr Eisner also had a sharepost here that explains what happens sometimes when proton pump inhibitors do not work. You can read that posting here.    Here is some information on the testing they do to diagnose acid reflux. There might be something here that you can suggest to your doctor to confirm.   Hope this helps! Stay in touch and let us know how you are doing!Vicki M