L-lysine and teeth cleaner in water?

Hi all,
I've been adding l-lysine to my cats' water as one of them had been sneezing (he seems to be ok now ) and would like to continue giving it to them. I usually add a teeth cleaning liquid to their water but haven't been doing that since I started with the lysine. Does anyone know if it's ok to use both? I don't want to overdo it but I would like to give both to the kitties.