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Pharmacopsychiatry 2003; 36(3): 98-104
DOI: 10.1055/s-2003-39983
Original Paper
© Georg Thieme Verlag Stuttgart · New York

Therapeutic Drug Monitoring of Tricyclic Antidepressants: How Does it Work under Clinical Conditions?

M. J. Müller1 , A. Dragicevic1 , M. Fric3 , I. Gaertner2 , K. Grasmäder4 , S. Härtter1 , E. Hermann5 , H. J. Kuss6 , G. Laux3 , W. Oehl5 , M. L. Rao4 , N. Rollmann1 , H. Weigmann1 , M. Weber-Labonte5 , C. Hiemke1
  • 1Department of Psychiatry, University of Mainz, Mainz, Germany
  • 2Department of Psychiatry and Psychotherapy, University of Tübingen, Germany
  • 3Bezirksklinikum Gabersee, Wasserburg/Inn, Germany
  • 4Department of Psychiatry, University of Bonn, Bonn, Germany
  • 5St. Valentinus-Krankenhaus, Kiedrich/Rheingau, Germany
  • 6Department of Psychiatry, University of Munich, Munich, Germany
This research work was supported in part by the Bundesministerium für Bildung und Forschung (BMBF). It was a subproject (3.8) of the Competence-Net Depression/Suicidality (Grant 01GI9924)
Further Information

Publication History

Received: 6.2.2002 Revised: 11.4.2002

Accepted: 8.8.2002

Publication Date:
13 June 2003 (online)

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Therapeutic drug monitoring (TDM) of tricyclic antidepressants (TCA) is established in the treatment of depression to optimize outcome and safety. However, there are few reports on TDM under naturalistic clinical conditions. In the present study, we investigated a TDM group (TDM) and a randomly assigned parallel group without TDM (no-TDM) while on TCA treatment. Serum levels were analyzed in both cohorts, but feedback and dose recommendation were only provided for the TDM group. Serum levels of TCA were assessed by high-performance liquid chromatography (HPLC). The outcome was measured weekly using the Hamilton Depression Rating Scale (HAMD), the Clinical Global Impressions Scale (CGI), and the UKU side-effect scale. 84 patients with depressive disorder according to DSM-IV were recruited in three centers (TDM, n = 43; no-TDM, n = 41; mean age 49.9 ± 13.2 years, 63.1 % female). Patients were treated with either amitriptyline (n = 69) or doxepin (n = 15); the mean dosage at endpoint was 126 ± 35 mg and 155 ± 47 mg, respectively. The mean study duration was 21 ± 8 days. Both groups improved according to HAMD (from 25.2 ± 8.4 at baseline to 12.0 ± 7.4 at endpoint) and CGI scores (68 % responders). Moderately severe or severe side effects occurred in 16 % of patients. Adequate dose adjustment was significantly higher in the TDM group (60 % vs. 46 %, p < 0.05); this led to a significantly higher rate of therapeutic serum levels in the TDM group (58 % vs. 44 %, p < 0.05). Direct effects of TDM were not found for effectiveness. Therapeutic TCA serum levels over weeks one to three, however, were associated with significantly better outcome at endpoint (p < 0.05) as measured with changes in the HAMD or CGI response rates from baseline to endpoint. Finally, considerable side effects occurred significantly more often when serum levels were above the therapeutic range (27 % vs. 11 %; p < 0.01). We conclude that treating depression with TCA can be optimized by early TDM, which is superior to clinical judgment on its own. Since the psychiatrists in charge were less than completely ”compliant” to the recommendations provided together with serum levels, the effect could be more pronounced than this study shows. The results encourage further studies in order to optimize antidepressant pharmacotherapy when using TDM appropriately.