Stay with the victim until help arrives. Don't, if at all possible, deal with the situation by yourself. Share the responsibility with others. Don't leave the victim alone. It is desirable to confront persons you care about with their dangerous behaviors, but not when they are under the influence of alcohol or other drugs.
Some intoxicated persons become agitated and violent.
Don't give the victim food or liquids, including coffee, tea or any other stimulant. If a friend's life is in danger, make it the priority.