Even though the original title was "The Cocaine Fiends" , and cocaine is the main plot point, no one is ever actually shown doing the drug on screen (every time someone goes for a line, the film cuts to a shot of the dealer watching with glee that he has a new customer/victim).
Late in the movie, the cocaine addicted brother gets the money to get his cocaine 'fix', and is next seen in a Chinese opium den having an opium pipe prepared for him. Cocaine and opium are unrelated drugs, and one will not satisfy an addiction to the other.