We've known about this for months, but today
the NBA made it official:
The NBA announced today that Darius Miles of the Boston Celtics has been suspended without pay for 10 games for violating the terms of the NBA/NBPA Anti-Drug Program at the end of the 2007-08 NBA season. His violation of the program involved phentermine.
In hindsight, phentermine, an appetite suppressant, makes much more sense. Miles originally tried to come back last season, and an appettite suppressant might have come in handy were he struggling to get back into game shape.
NBA Officially Announces Darius Miles' Fine - NBA FanHouse