Issues getting 18mo to take medication

Our little one has been having myoclonic seizures since 13mo. We were first on keppra and now are on depakote and onfi. He used to be good at taking his medications. He now refuses to even let us get the syringe near his mouth. Things we've already tried - - Depakote sprinkles instead of liquid. We've put it in apple sauce, pudding, oatmeal, icing. He's hip to our plan and refusing anything on a spoon. - Putting it in various drinks, either sippy cup, straw, small cup he does himself. - Trying something cold first like ice cream/Popsicle to numb his taste buds a bit. - Waiting until he's mostly asleep and trying to get it in then. - Having his big brother do what looks like the same thing so he's mirroring his behavior. I'm at a total loss. Anyone else have trouble getting their kids to take their meds? In 5 months we've yet to have a seizure free day and we have no idea if its the meds aren't working or if its because he's not getting what he needs. Thanks!