title: The kinetics of amitriptyline following single oral dose administration to man.
abstract: Amitriptyline and its metabolite, nortriptyline, were measured in the plasma of eight humans for 96 hours following oral administration of a 75 mg dose of amitriptyline hydrochloride. Based on the 8 to 96 hour post dosing plasma concentration data, the terminal exponential half life of amitriptyline +/- S.D. was 22.4 +/- 4.3 hr. Based on the 24 to 96 hour concentration data, the "apparent" terminal half time of nortriptyline +/- S.D. was 26.0 +/- 7.4 hours for seven subjects. For these same seven subjects the relative area under the plasma concentration time curve of nortriptyline +/- S.D. was only 0.88 +/- 0.34 times that of amitriptyline. One subject whose apparent nortriptyline half time was 108 hours had a nortriptyline bioavailability 3.83 times that of amitriptyline. Average steady state plasma levels for 12 psychiatric patients who had received a 50 mg oral dose of amitriptyline three times a day for an average of 32 days could be predicted from the single dose plasma clearance of amitriptyline.
mesh_terms: D000328:Adult; D000639:Amitriptyline / Q000097:blood / Q000378:metabolism* / Q000627:therapeutic use; D006207:Half-Life; D006801:Humans; D007700:Kinetics; D008297:Male; D009661:Nortriptyline / Q000097:blood
chemical_list: D000639:Amitriptyline; D009661:Nortriptyline