Was in a similiar situation.

Told my friend he was getting carried away with the coke.

I told him, "If you dont stop your going to kill yourself".

He got agitated at my concern.

By weeks end a State patrol found him dead next to his car with the tire off his car.

He had a heart attack changing a flat tire and died on the side of the road.

28 is too young to have a heart attack.

Later found out from others he had just done an 8 ball of coke.

Greg Hettich. 1988.