I believe drug-related issues should be handled by the parents of a minor, not the courts. Of course this could vary depending on what the drug related issue is. If a minor is trying to sell drugs, then that problem should be addressed in court. If the minor simply has a problem with drug usage, then that should be handled as a family matter, because that is exactly what it is.
I think that it should start with the parents first and see if they can do anything to help their child. Maybe they can switch schools, pay for rehab, or other options. If this isn't effective, then perhaps the courts do need to get involved in order to help the teen out.
I do think parents should be, for the most part, handling the drug related problems of their children. Especially if it is a less harmful substance, such as marijuana. Perhaps the parents could ask for the help of the judicial system if and when the problem becomes an even larger one.
Drug related issues should be handled by the courts, rather than by the parents of the minor, because it is most likely the parents who have led to the behavior in the first place. A minor who drinks or uses drugs is a concern for all of us, not just for the parents.