Ours has had a spit up problem since birth. However, it wasn't reflux...she just couldn't keep it all down. We're not quite sure why. She still has that problem. It would happen a lot during naps and night time sleep as well.
What helped us was to treat it like reflux. We raised her matress about 20 degrees. We started putting her on her tummy to sleep (but that didn't happen until she had mastered head control at 2.5 months). She took quite a few naps in her car seat around your lo's age. We also put rice cereal in her bottle at night (not to help her sleep through the night...we knew that didn't help. However, it helped her keep her milk down, which was the point).
This helped, but didn't eliminate the problem. You might want to get it checked out and see if it is reflux. Until then, you can treat it as though it was reflux without the medication.
*HUGS*
Sonya =P