Here's a thought! How about, "“Honor your father and your mother, as the Lord your God has commanded you, so that you may live long and that it may go well with you in the land the Lord your God is giving you."? (Deuteronomy 5:16, emphasis added)) I don't see where it says "unless you disagree with your mother and father." And Jesus followed this up in the Gospel of Mark; "And he continued, 'You have a fine way of setting aside the commands of God in order to observe your own traditions! For Moses said, ‘Honor your father and mother, and, ‘Anyone who curses their father or mother is to be put to death.’" (That can't be good.)
Whether the drug is harmful, or illegal, is immaterial to this argument. If parents don't want their children to do them, and the children live under the parents' roof, they are obligated to accede to their parents' wishes. The solution to this dilemma is simple; "Get straight or get out!".