I've Been Experiencing A GERDlike Symptom. The Specialist Has Viewed

I've been experiencing a GERDlike symptom. The specialist has viewed my throat/esophagus/nose with a camera inserted through my nose. I have excessive saliva continually. Currently he has changed a prescription to 40 mg Propantazole 2X per day before meals. Still there is no relief. Questions: is it safe to take that much of the drug and what other solutions may be possible?
Thanks.