P.G.
As Mary Poppins says, "a spoonful of sugar makes the medicine go down". A small amount of a "treat like substance" to get him to take medicine to prevent brain damage isn't a bad thing. The ice cream is NOT a treat in this situation, it's a good tasting vehicle to take nasty medicine with.
And she can be honest with him about the yummy stuff so that the yucky stuff won't be so bad. My son likes to give himself his medicine, so if there's a way for her to work WITH him to take his medicine then that's the way to go. I'm so proud of my son when he takes the yucky medicine and drinks down his juice to make the taste go away. I get goofy about it with him so he thinks it's funny and it usually works.