Duloxetine serum concentrations and clinical effects. Data from a therapeutic drug monitoring (TDM) survey.
BACKGROUND
The aim of this study was to relate drug concentrations in serum and clinical effects in patients treated with the new antidepressant duloxetine.


METHODS
Data were obtained from a newly established therapeutic drug monitoring (TDM) survey. Duloxetine was measured using HPLC with UV detection and clinical effects by the clinical global impressions (CGI) scale for improvement.


RESULTS
The study included 103 depressed inpatients (69% female). Patients under duloxetine monotherapy who were very much improved according to CGI had significantly (p<0.05) higher serum levels than patients with moderate, minimal or lacking improvement (mean+/-SD and range, 93+/-53 ng/mL and 30-182 ng/mL and 47+/-39 ng/mL and 5-178 ng/mL, respectively). Daily doses were similar in the two groups (76+/-27 vs. 83+/-27 mg/d). Receiver operating characteristics (ROC) curve analysis revealed significant predictive properties of duloxetine serum levels (p=0.011) for improvement with a lower threshold concentration of duloxetine of 58 ng/mL.


CONCLUSIONS
The findings indicate that therapeutic drug monitoring of duloxetine and titration to steady state serum concentrations above 58 ng/mL is useful for treatment optimization.
Waldschmitt
C
C
Department of Psychiatry and Psychotherapy, University of Mainz, Mainz, Germany.
Vogel
F
F
Pfuhlmann
B
B
Hiemke
C
C
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000928:Antidepressive Agents / Q000008:administration & dosage / Q000097:blood* / Q000627:therapeutic use*; D002851:Chromatography, High Pressure Liquid; D003866:Depressive Disorder / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D016903:Drug Monitoring; D000068736:Duloxetine Hydrochloride; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012720:Severity of Illness Index; D013057:Spectrum Analysis; D013876:Thiophenes / Q000008:administration & dosage / Q000097:blood* / Q000627:therapeutic use*; D016896:Treatment Outcome; D014466:Ultraviolet Rays; D055815:Young Adult
D000928:Antidepressive Agents; D013876:Thiophenes; D000068736:Duloxetine Hydrochloride