I have used time released Melatonin to help my wife sleep (thanks again, LindyLou). This medication is OTC, but be sure to check with your husband’s doctors before beginning to use any new medication.
Exercise can help but lots of folks can't tolerate much. We walk and it helps. Sleep disruption is so common with dementia. Good luck!
Kalm Assure is a product that is all natural, no melatonin. Ordered from Amazon or your local health food store may carry it. It is a rather large bilayered tablet, but it can be crushed. It is the safest thing to give your husband, but please run it by his physician first.
For both the patient and the caregiver!!