Test Catalog Search Home Test Catalog Search Testing Choices: From the standard to the extraordinary × Search Clear Filter by: Clear all Method(s) High Performance Liquid Chromatography/ Tandem Mass Spectrometry (LC-MS/MS) (1) Sample Type Blood (2) Serum or Plasma (3) (-) Urine (1) Test Area (-) Therapeutics (1) Test Category (-) Antiparkinsons (1) Therapeutics (1) Test Sub-Category Anticholinergics (1) Test Test Name 4680U Trihexyphenidyl, Urine