nan HA is good stuff!!! DS was on that
DD on the other hand is on novalac AR (soon to switch to karicare de-lact when it arrives in the post, but this is because of tempoart lactose intollerence after gastro - but thats not important here...)
Zantac is said to be given 30mins before a feed. If it can't be well thats ok as it's fine to be given along side the feed. I use a tiny 1.5ml syrings (it's skinny) and slip it in with the bottle teat as she is feeding. She sucks away and is mostly none th ewiser. Sometimes she will stop and think ewwww!!! but then realise there's milk so sucks away again.
Zantac can be prescribed by your doctor and is fairly weight sensitive so dose will/may need adjusting every few weeks.
The zantac over the counter is the same strength, but more expensive. I'd consult with your doc and say that you want to try it... I doubt he'd say no.