Accutane is a derivative of Vitamin A. It affects the sebaceous (oil) glands and shrinks them (somehow

). This oil is what traps the stuff in the pores and provides a place for bacteria to grow...so decrease oil=decrease acne. You aren't supposed to use topicals while on Accutane. You just have to wait for the pimples you have to heal. In fact, breakouts get worse for a while.
It's supposedly permanent but I know that my acne came back after a few months, albeit less severe than before. "They" say you can take up to three courses to get a full result...if it doesn't work by then, it won't be a "cure" for you. HTH.