Terbinafine
"My pinky toenail has been infected since 2000.  I finally asked my doctor for a prescription because I was tired of wearing shower shoes in my own shower and being worried about spreading it to my wife or kids. I'm two and a half months into the treatment and I can definitely see a difference. Where the nail was yellow, brittle and thick, it is now clear and looks more like my other toenails.  It's not quite back to the way it was but it's a huge improvement.  The nail is still a little thicker than the others but it's not nearly as brittle as it was.  The other thing I noticed is that the toe does not have any fungus around the nail anymore, no itching, burning or swelling in that area in over 2 months.  No side effects either."