I know, I know, I give a lot of links…
but they all have a lot of info to help you research, so you can know how I (or anyone else answering you) have come to my conclusions…
so, the long answer is:
read here:
Prevacid 101:
scroll to the last page of this post, (it’s actually also about other PPIs like prilosec, too)
https://www.infantreflux.org/forum/forum_posts.asp?TID=1936&PN=0&TPN=1
and, for how to tell your dr:
TELL dr you need new rx for____, don’t ask. TELL.
FAX FAX FAX the dr
don’t wait for a call…
start off with a THANK YOU 
keep it short & sweet
stick to the FACTS (no emotions and ramblings)
state current meds, doses & symptoms
make request- flat out- short & sweet
provide pharmacist name & contact info
THANK AGAIN
follow up by calling office to tell them fax was sent
call again later to discuss requests made in fax, ie:
is RX called in yet?
THANK YOU