My Wife Has Alzheimer's, Level 4-5. She Has Sundown Syndrome

My wife has Alzheimer's, level 4-5. She has sundown syndrome many, but not all of the time. At that time she doesn't know where she is, packs up clothes and stuff for an imaginary trip "home." I would like to have something (med) that would relieve anxiety. Is Risperidone approprite for this? Sounds like it doesn't fit and has undesirable side effects. Thanks. Wilbur Shults. Oak Ridge, Tennessee.