Here you can't approach their doctor. But you can call 911. I believe too the mobile crisis or crisis networks can be of assistance to you. They can send out a team with or without the police. Finally, have you approached your Mental Health Association/Society? They would likely have a list of 1) resources for your self regarding supports of your own and 2) some sort of course of action to assist you.

Unfortunately, unless the individual is at risk of harming themselves or others they cannot be commited without their consent.

Finally I applaud you for having the will and wherewithall to help your family member.