My spouse is bipolar and has dementia. He refuses to take some of his meds and gets very irritable. How can I help him to realize he needs?

A book by Julie A. Fast and co-authored by John D. Preston:
1) Take Charge of Bi-Polar Disorder - A 4-Step Plan to Manage the Illness

This book and her websites will go along way in helping anyone deal with bi-polar. Ms Fast is herself bi-polar.

sneak it into his coffee if you have to.

If he has dementia, you're not likely to "help him realize" anything he doesn't want to do. If you can't cajole him into taking his meds, then try assertiveness by giving him his pills when it's time in a tablespoonful of applesauce and saying, "Take this. This is non-negotiable!!" If you can't get him to take them that way? He needs medication to make him more compliant. It's out there. Talk to his doctor.