If a friend is experiencing a medical emergency from drinking too much, consuming a drug, or any other reason, you should call for help.
On campus, call Public Safety and off campus, call 9-1-1.
Stay with your friend and answer any questions that the responders have. By doing so, you are being a good friend, a good member of the University community, and may have some protections from University and legal penalties.
This policy is outlined in the Code of Conduct, under 2.0.1 Responsibility to Others.
Check out the video below! While it's from Purdue, the information about the Medical Amnesty policy is the same as here at USI.