About MITCHELL, WHITTAKER, & WU (LOUDOUN MEDICAL GROUP PC) Mitchell, Whittaker, & Wu (loudoun Medical Group Pc) is an internal medicine provider established in Alexandria, Virginia specializing in internal medicine. The NPI number of Mitchell, Whittaker, & Wu (loudoun Medical Group Pc) is 1174759278 and was assigned on June 2009. The practitioner's primary taxonomy code is 207R00000X..