Dear Vinny,
As a family member, szadmin has given you the list of things you can do.
Legally, in the USA, only a court can order involuntary treatment.
Please make sure to document all of your brother’s behaviors that show he is a “danger to self or others” or if he is “gravely disabled” by the illness and any documentation of legal standards for involuntary treatment used where you are.
If you could find out the treatment laws in your state
( http://www.treatmentadvocacycenter.org has a map of the USA with each state’s laws) or nation if you are in another country, you might be able to start the legal process for involuntary treatment.
All best to you and your family, especially your brother.