Nope. Any examination required for initial licensure is no longer deductible (although it used to be). This includes the bar exam for lawyers as well. I had the same question this year but found the official IRS rule. I'll try to find a link.
Look at Publication 17 from the IRS and it says that fees for initial licensure and forgetting initial licensure are NOT deductible. So you can't deduct your initial medical license expense either.
This CPA has a good website and has a list of stuff that is not deductible and includes the bar and GRE. USMLE would also fit in that category as it is a required exam for qualifying for a profession. http://www.jamesdance.com/deductions.htm