Relationship between antidepressant response and plasma concentrations of fluoxetine and norfluoxetine.
The relationship between plasma concentration, clinical outcome and side-effects was examined in 23 patients with major depressive disorder (DSM-III-R) treated with fluoxetine. All patients received a fixed dose of 20 mg for 6 weeks. Good response was observed in 57% of patients, while 30% of patients had moderate responses after 6 weeks of treatment. Fluoxetine and norfluoxetine plasma concentrations were not significantly influenced by age and sex. At 6 weeks, plasma fluoxetine concentrations were not significantly different between responders and non-responders to treatment (82.2 +/- 59.6 micrograms/l vs. 84.7 +/- 6.7 micrograms/l) or those with or without side-effects (74.6 +/- 28.7 micrograms/l vs. 87.0 +/- 66.6 micrograms/l). Similarly, norfluoxetine concentrations were not significantly different for responders and non-responders (65.5 +/- 28.9 micrograms/l vs. 66.5 +/- 26.2 micrograms/l) or those with or without side-effects (66.6 +/- 14.4 micrograms/l vs. 61.5 +/- 33.6 micrograms/l). Plasma concentrations and clinical outcome were not related in a simple manner. Further studies are needed to evaluate the role of monitoring plasma fluoxetine/norfluoxetine concentrations as a routine procedure.
Norman
T R
TR
Department of Psychiatry, University of Melbourne, Austin Hospital, Heidelberg, Victoria, Australia.
Gupta
R K
RK
Burrows
G D
GD
Parker
G
G
Judd
F K
FK
D000328:Adult; D002851:Chromatography, High Pressure Liquid; D003866:Depressive Disorder / Q000097:blood* / Q000188:drug therapy / Q000523:psychology; D005260:Female; D005473:Fluoxetine / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000097:blood* / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales
D005473:Fluoxetine; C036139:norfluoxetine