My father is suffering from Mania.

My father is suffering from Mania. We consulted with Dr but my father is not taking prescribed medicines properly. He doubts my mother, beats her inhumanly. He also does not trust me and sister as well. Sometimes he talks normally and suddenly episodes starts in his mind and he start behaving so dangerously. He talks like I have 15-20 days of life, ai first kill your mother and then my selves. Which is very stressing for me and whole family, we are helpless now, do not know what should we do now. Since he is not ready to go to Dr(last time it took 3 days to convince him to visit dr). Now we don't know what can be done, I cant let him stay with my mother in my absence as he is talking and threatning openly. Could someone experienced in such cases suggest next steps? What kind of treatment can be given? He is not ready to go to any Dr as of today. It would be great help if someone suggests any good treatment for him, we are so stressed and mentally disturbed. Thanks