Test Catalog Search Home Test Catalog Search Testing Choices: From the standard to the extraordinary × Search Clear Filter by: Clear all Method(s) Gas Chromatography (GC) (1) Sample Type (-) Blood (1) Serum or Plasma (1) Urine (1) Test Area Therapeutics (1) Test Category (-) Antiparkinsons (1) Test Sub-Category (-) Anticholinergics (1) Dopamine Antagonists (1) Test Test Name 4680B Trihexyphenidyl, Blood