Hi there! I am going through the EXACT SAME THING with our 5 month old. But I want to share something extremely important first... Gabby also has severe reflux which it sounds like your LO does, too. She was on Prevacid 7.5mg twice a day PLUS the max dose of Zantac twice a day and she was still throwing up and crying when she ate/burped/refluxed. She was constantly growing out of her Zantac dose and we got to the point where she had maxed out on both drugs.
We ended up taking her to Duke.
I, too, was giving her Prevacid and Zantac together first thing in the morning then again right before bed. But guess what? You cannot give Zantac and Prevacid TOGETHER. In layman's terms, Prevacid needs the proton pumps (which makes the acid) to be turned on in order for it to effectively turn them off. If you give her Zantac (an H2 blocker) at the same time, Zantac prevents the Proton Pumps from being turned on (using a different mechanism of action) and therefore, Prevacid can't turn off the pumps and be effective.
The pediatric GI at Duke said, in theory, she should not need BOTH Zantac and Prevacid if she has enough Prevacid and if you're dosing it properly. He said if you are going to continue giving her Prevacid AND Zantac, then they need to be dosed 4 hours apart. The GI increased her dose from 15mg (total) to 22.5mg (total) and we changed her dosing schedule. We started giving Gabby Prevacid when she first wakes up and then we try to hold her off at least 30 min before eating (Prevacid needs an acidic environment to work... milk makes the stomach more alkaline). Then we were giving her Zantac at noon-ish, Prevacid again at 6ish and her last dose of Zantac at the dreamfeed. We did not change her dose of anything... Just the timing and she's a completely different baby. No reflux! No crying when burping! No vomiting!
And it gets better! For the last week, we have been giving her NO Zantac! We split her dose of Prevacid into 3 doses (7am, 12pm-ish, 6pm-ish) and she is FABULOUS! I seriously can't believe it. I am a total believer in a higher dose of Prevacid and no Zantac to interfere with Prevacid!
I hope this helps!
Just an FYI - I am in the medical field and have read all the supporting studies in the literature to support the theory. There's a lot of pharmacologic studies that demonstrate the necessity to space PPIs (Prevacid) and H2 blockers (Zantac) at least 4 hours apart.
Poor Gabby has suffered with several reflux since the very beginning (and confirmed food allergies)... I only wish we had known this all along!
I hope this helps you and your LO!!!
Looking forward to hearing the responses about our non-sleeping babies. Mine is happy, too. But she needs to sleep!