My Father Is 92 Years Old He Is Diabetic, Has

My father is 92 years old he is diabetic, has mild dementia last Saturday August 15 he started insulin treatment he is taking 10 unites and he is acting very weird, hallucinating talking in his sleep, seeing and talking to people that are not there, irritable, tired, sleepy, no appetite, getting up frequently at night to urine. Is this normal? should I take him to his doctor? Please help.
Thanks,
Mickey