I haven’t had any luck with medication for bedwetting.
Immature anatomy isn’t the reason I wet the bed. My anatomy matured enough that I stopped wetting the bed when I was very little. Consequently, drugs that overcome late development (low hormones, small bladder, …) have no effect (or even a negative effect) on my bedwetting. Given the side effects (some of which are quite nasty) and the fact that I have to wear protection anyway, I have given up on trying to control my bedwetting with drugs.
However, there are drugs — DDAVP, Ditropan, Levsin or Tofranil — that are effective to treat many common causes. Some have nasty side effects, and their effect on bedwetting tends to diminish with extended use. But they can help control bedwetting, particularly for short periods. They can significantly cut the risk of a wet bed (or sleeping bag) on a sleepover or for a few days away from home.