Anyone have experience with Risperidone?

My hubs has Alz and Dr is prescribing this to replace prazosin for PM anxiety and restlessness.D is 79 and was diagnosed 5 years ago. The anxiety and extreme afternoon restlessness started about 4 or 5 mos ago and has gotten progressively worse. He will not sit still. He is up and down, up and down, until I think I will lose my mind. While he is up, he turns on lights, (never off) plays with the cat food, and just in general picks up stuff and puts it somewhere else. Sometimes he doesn't even sit completely down before getting up again.
I did read and the Dr agreed that it can cause heart problems in some people. Less than 1/2 of 1 percent. Other than dementia he is healthy as a horse. Strong heart, good BP, good cholesterol. Great health for his age.
He gets all his care at the VA and his geriatric shrink says that as matter of policy they don't give benzodiazepines to dementia patients, so no Zanax or anything of that type.
The prazosin, which we tried first, actually made him worse.
Thanks for any help you can give.
And thanks to all you guys for logging on everyday and helping fellow sufferers.