Please, please, please read some books on how to discipline the ADHD, ODD child! Go to the library and check out one that I like: "Survival Strategies for parenting your add child: dealing with obsessions, compulsions, depression, explosive behavior and rage" by George T. Lynn, M.A., C.M.H.C
This book discusses techniques not using medications.
I wish you the best!
If your stepson is a threat to himself or to others you should take him to the nearest mental health hospital for an immediate evaluation. There may be an underlying cause for his out of control behavior such as a mood disorder. You don't say what age the child is but if he is attacking his father he needs mental health intervention immediately. That can include family therapy so you all can learn to cope with his behavior and/or find out what is driving him to do this. If he has calmed down is not an immediate threat you can schedule an appointment with a mental health counselor or psychologist to help you with his behaviors. Good luck