Hi Heidi,
I am one of the naturopaths at the new Belly Belly PC.
The side effects for Losec would be the same in a baby only multiplied because you are dealing with such a small body.
There are lots of natural remedies and ways of relieving reflux.
I am running free infant clinics every Tuesday at the centre if you can come in just book in and only pay for any remedies.
If you are nowhere near Melbourne I can send out a whole sheet on what to do and a couple of remedies.Just email me on jocelynmking@gmail.com
Hope to see you and your little one,
Cheers
Jocelyn