The season 4 episode "Blood Brothers" features heavy usage of crack. It is no way promoting it and shows its negative effects of it.
Main protagonist smoking three cigarettes at a one go is shown in the episode " Pilot " ,however that was done as a trick to sense the laser rays . Except that ,he's never seen smoking or using alcohol.
Season 6 episode " Twenty questions" features protagonist's fight to prevent his 15 year old teenage friend from alcoholism .Scenes of excessive beer consumption and intoxication of teenagers is shown in two instances of this episode . No promoting of alcoholism occurs though . Adverse effects of alcohol consumption and bad peer group association is emphasized
Occasional smoking, consumption of wine or other alcoholic beverages. Mostly shown as used in moderation.
Smuggling, production or possession of heroin, cocaine, methamphetamine and PCP is shown in various episodes.
Illegal drug operations are severely fought against by the allied characters, and the main protagonist frowns upon the use of tobacco and alcohol products.