Does anyone use painstop on a child under 1?

My GP recomended PS as DS (9 months) is a really bad teether - and I mean bad! He is 12+kgs so it within the weight range for PS - and thats what my GP has always told me to go by - the weight rather than the age. Panadol & Nerofen dont even touch the sides of the pain but PS seems to work well.

The reason I ask is I told my SIL about it and her chemist said that it should not be used on children under 2 and that it causes SIDS! Im shocked! I dont want to use it if its bad - but I also trust my GP....

Not sure what to think!

Kate