Don’t add any flavourings! Marci-kids told us that it would render the prevacid unstable in less than a few days. Even when adding it in on the side, I recall Dr. Phillips telling me that you need to watch which kind of flavouring it is- something basic or neutral vs. something acidic. We actually add Hershey’s syrup in on the side- full of sugar so not the best idea, but it was something I learned on here. I can understand your reason for wanting some kind of flavour though… it tastes nasty without anything.
Can you mix it in with a ml of formula? We did that for a while with Hailey.