title: The peripheral anticholinergic activity of tricyclic antidepressants: comparison of amitriptyline and desipramine in human volunteers.
abstract: The effects of three single oral doses (25 mg, 50 mg and 100 mg) of amitriptyline and desipramine, and of placebo, were compared on a range of cholinergic functions (resting pupil diameter, pilocarpine-evoked miosis, baseline-sweating, carbachol-evoked sweating, salivation, heart rate) in eight healthy volunteers. Three measures (pilocarpine-evoked miosis, carbachol-evoked sweating and salivation) reflected the antimuscarinic property of the antidepressants; in two tests (pilocarpine-evoked miosis and salivation) amitriptyline appeared to be more potent than desipramine. Resting pupil diameter was not affected by amitriptyline, whereas desipramine caused mydriasis, indicating that pupil size is not a reliable measure of anticholinergic activity in the case of drugs which also affect adrenergic mechanisms. Baseline-sweating and heart rate were not affected by the antidepressants.
mesh_terms: D000328:Adult; D000639:Amitriptyline / Q000494:pharmacology*; D003891:Desipramine / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008297:Male; D010276:Parasympatholytics; D010919:Placebos; D011674:Pulse / Q000187:drug effects; D011680:Pupil / Q000187:drug effects; D012472:Salivation / Q000187:drug effects; D013546:Sweating / Q000187:drug effects
chemical_list: D010276:Parasympatholytics; D010919:Placebos; D000639:Amitriptyline; D003891:Desipramine