Reflux and Zantac

Katherine
Hi! My 6 week old has terrible silent reflux and today they upped his dose from .7ml to .9ml 3x a day because he has gained weight and it was starting to work less and less. Are any of your babies on Zantac? If so, what is the dosage?
He is up every 2 hours at night and screams in pain when he spits up. We are exhausted...