Are there medications for sundown syndrome that helps the person sleep through the night?

Because of the ongoing liver damage, the doctors could not justify more drugs to help my Dad sleep.

what did help was edible marijuana. I bought orange flavored candy bars for him. Just one tiny piece the size of my thumb nail was all it took for him.

he started out with half a square of that candy, but over time discovered half of that worked too. I asked him how that was working for him after he had reduced the quantity. He said it was fine....but he missed the party.

Not sleeping is a common problen and can quickly burn out the caregiver. You need to find a doctor who understands that your health and peace of mind matter too, one who is experienced in dealing with dementia and is willing to experiment to find a medication that works. If this isn't happening with your family doctor then perhaps a gerontologist, geriatric psychiatrist, or neurologist may be more helpful.