What does smoking oxycontin do to you?

Many things: Oxycodone, when smoked, gets into the body (and the brain) very quickly, within seconds. It has a greater chance of producing overdose, and can cause physical dependence and addiction more quickly when smoked than when taken by mouth, but both routes of administration will cause addiction. It is not good for the lungs or heart either, since many impurities present in the smoke are toxic.