I just clicked on the above link which took me to the article. I did not receive the "page not found" error message like you did. I doubt one needs to be a member of medscape to read it. I also visually verified the correctness of url in the above posting. I copy the url here one more time,
http://www.medscape.com/viewarticle/506604?src=mp . If this doesn't work try typing in the url onto the address box to see if that works.