Police respond to report of driver passed out or sleeping in van in fast food restaurant parking lot.  Police find driver slumped behind wheel apparently sleeping with engine running.  Once awoken he appears sluggish and lethargic and there is an odor of alcohol.  Driver admits to drinking two (2) beers that afternoon and that he pulled over because he was not feeling well due to an adverse reaction to an intravenous medication.  Driver performs poorly on portions of field sobriety tests and refuses post arrest breath test.  Defense prepared to argue Police failed to properly investigate medication use and are unable to distinguish between effects of properly prescribed medication and alcohol use.  DWI Charge Dismissed prior to trial.