HELP!!!

Jasmine
My son is always spitting up even vomiting at times he is on the acid reflux medicine rantandine i think you spell it but it doesn't work we he spits up his breastmilk we also have tried enfamila A.R and Gentlease we have tried similar almentuim none of those work he still spits up HELP me please What do you recommend? 
Have anyone tried similac for spit up and been successful ?