Plasma tricyclic drug levels in amitriptyline-treated depressed patients

Abstract

In a double-blind phenelzine controlled clinical trial, 49 depressed outpatients were treated with a fixed dose of amitriptyline (AMI) 150 mg/day for 6 weeks. No significant relationships were found between steady-state plasma levels of AMI and its metabolite, nortriptyline, at 4 weeks and therapeutic response at 6 weeks or side effects. In the patient subgroup with more severe endogenous symptoms, there was a general trend for a weak positive association between AMI plasma levels and clinical improvement. Plasma tricyclic determinations appear to have little if any predictive value for antidepressant effect in outpatients treated with AMI.

Measurement of serum drug levels in the assessment of antidepressants.

“…The inclusion of non-responders should be avoided as far as possible. Two recent large studies (Coppen et al, 1978;Robinson et al, 1979) on amitriptyline which reported no relationship are open to criticism because of the very low overall response rate achieved. Potter & Goodwin (1978) criticised the study by the WHO group (Coppen et al, 1978) which reported a response rate of 35% as being rather inept in the selection of patients thought likely to respond.…”

“…Potter & Goodwin (1978) criticised the study by the WHO group (Coppen et al, 1978) which reported a response rate of 35% as being rather inept in the selection of patients thought likely to respond. When the same criterion of response in the WHO study (a final HRS of 6 or less) is applied to the study of Robinson et al (1979) a response rate of only 16% is apparent.…”

“…Since the centres were in different parts of Europe some differences in presenting psychopathology and rating attitudes would be expected (Montgomery, Asberg, Traskman & Montgomery, 1978) and these would increase variance. The study by Robinson et al (1979) was conducted on out-patients who included as far as one can tell a relatively difficult group of patients with reactive depression who were not as likely to respond to pharmacotherapy.…”

The Measurement of Plasma Tricyclics in a Saudi Population

“…Several studies [11][12][13] showed linear relationships, as with imipramine. Other studies [14][15][16] have revealed a curvilinear (window-like) relationship similar to that of nortriptyline, and yet others [17][18][19][20] found no relationship at all between blood levels and outcome. Information on doxepin is limited, 20,21 and the reason for this is obscure.…”

“…Reisby et al 4 and Robinson et al 18 suggested a stronger relationship between plasma levels and clinical outcome in endogenously depressed patients compared with nonendogenously depressed patients. On the other hand, patients with endogenous unipolar depression (delusional patients) are far less responsive to tricyclic drugs than nondelusional patients.…”