Unconciously behaving drunk at odd hours

Hi, This is about my father who is 51 years old. He has a habit of taking sleeping pills for the last 10 years. Lately, for the last two to three years we have had weird experiences with him every once in a while. The last time it happened, he woke up in the middle of his sleep came to me and asked for food. He started eating and talking to me...and while he was talking I noticed that he was talking endlessly without a pause and that too about random unrelated topics and he would not stop for even a second and then he asked to me to go out and bring some papers from the car I said it's too late we can do that tomorrow but he started insisting and he even came along to bring those papers and then we brought those papers then talked about it for a while and then he started talking again about random stuff and then he started behaving like a drunk man and became out of our controls, however he does not consume any alcohol. We somehow made him to sleep by fulfilling his randome demands.