L.S.
Be calm. Ask him questions like why he feels the need to experiment with drugs. Ask him how long he has been using them. Tell him it will stunt his growth as a human, both mentally and physically, etc. Talk to him about the dangers. Ask him lots of questions and perhaps you need to visit a place where recovering addicts go or he may need to talk to an addict, maybe he needs to watch Intervention. He needs to understand the dangers. You really never know what you are smoking, injecting, etc. if you are buying something off the streets or even from friends. You need to ground him, but don't overreact where he thinks he can't talk to you anymore. You want to keep an open dialogue. Tell him that you will not permit this and that if you ever find him with drugs or on drugs again you will have to take away all of his privileges. Do you know if this is a one time thing or has he been using for a while? edited to add-- did you ask him if it was cocaine?? Could be anything smashed up and inhaled, like oxycontin, ritalin, or cocaine ... other things look like cocaine, too. If he has an addiction you need to set him up with therapy, if he was just experimenting he needs lots of talking to and lots of supervision. You know your son better than we do.