Hi Mike,
For many years I was on a combination of PPI's and Zantac. My PCP had me on a PPI in the morning, then 300mg Zantac at bedtime. There is no problem mixing the two.
Good luck finding an answer to your heartburn issues. Have you tried elevating the head of your bed?
I'm sure others will be by soon to add to this discussion.
Best wishes,
Denise