Have you given him any solids yet? Probably not, but when you do, you can mix the med is a very small amount of food and spoon it to him.
We always did the squirt/pacifier technique. I would just squirt a small amount in and then put the pacifier in his mouth to help him suck it down. He didn’t suck on a pacifier any other time but would for this.
Some moms have found using a small bulb syringe like in the tylenol bottles works better. IT takes a while, but you can get it in them more easily as you can fit it in their mouths better, etc.
Good luck. We went through this for a bit too, but once he got used to it, and I got better at giving it to him, it was so easy. Now he just chugs it down.