Our Family Physician Recently Prescribed Seroquel For My Father Who

Our family Physician recently prescribed Seroquel for my father who has been diagnosed with Dementia/Alzheimer's disease. He seems quite confident that this medication will help lessen or control his "outburst of frustration" that we are experiencing with his behavior. My mother is his primary care giver and is concerned about the side effects and the possibility of stroke, my dad has also been diagnosed as having "AFIB" and has had two by-pass surgeries in the past. How can we help her and what should she be watching for when it come to side effects?