Reflux baby

Anyone’s littles ones have reflux? Mine son was prescribed Zantac give 1ml twice daily He spits up a lot it was prescribed because he was crying in pain after feeding and hated being on his back. It seems to be helping but since he spits up a lot dosing is a challenge I give it during a feed usually at the beginning size it taste bad then let him wash it down with formula. Well he spit up soon after this happens frequently. Should I redose or wait till next scheduled dose?