Lesson 8 - Drugs

In Arthur Conan Doyle's books we know that Sherlock Holmes smokes a pipe and that he injects drugs on himself with a syringe. But in "Sherlock", instead of smoking, he takes nicotine patches: http://www.youtube.com/watch?v=dLuLTOwn3N8
I recently read the case "A Scandal in Bohemia" ("A Scandal in Belgravia") and I read the following: "...between cocaine and ambition...".
But one of the things that makes Sherlock unique is the fact that he takes drugs.
No other detective would take drugs! Poirot didn't, Miss Marple didn't, none of them did!
But if Sherlock died from a lung cancer, I would blame Mycroft because he gave Sherlock a cigarette for Christmas ("A Scandal in Belgravia") and that made him an addicted to smoking as we can see in ("The Hound of the Baskervilles").
And... Just for your safety, I won't give you steps to take drugs like Sherlock, just this once...