I feel for you! My 5 month old son and now 4 year old daughter went through and currently have the same problem. Our doctor and my husband's father (he is a General Practitioner) both strongly advised with both our children not to put them on any antacids unless it got desperate (meaning they were malnutritioned and not thriving). We were told that their digetive tracts are so small and sensitive and underdeveloped that inroducing something as strong as an antacid could really harm them and throw off the development of the gi tract and could potentially harm other aspects of their growth prermanently because so little research has been on the long term side effects of such strong medicine on such a little baby.
We ran the gamut of formulas and bottles for both my daughter and son and ended up sticking with what we started with; regular milk based Enfamil (the generic) and the Playtex Ventair Classic bottle.
We do put rice cereal in the bottle and that does help to keep the formula down and starting solid foods has made it better. My daughter literally overgrew hers overnight once she turned about 9 months old and we are hoping the same goes for our son.
It is inconvenient and messy to have the CONSTANT throw up and what bothered me the most was the discomfort it caused them for the first 3 months of their life. It no longer seemed to HURT them after about 4 months. The problem will correct itself naturally and we need to remember that sometimes just because a drug is available does not mean it is appropriate or safe:) Best of luck to you and know that as long as you are there for him and he is growing and smiling he will be okay!