Retrospective pilot study for analysis of antidepressant serum concentrations of citalopram and venlafaxine during inflammation.
BACKGROUND
Inflammation-mediated changes in drug metabolism may increase drug levels in blood and lead to intoxications. The objective of this study was to find out whether elevated serum levels of C-reactive protein (CRP) are associated with increased serum concentrations of the antidepressants citalopram and venlafaxine.


METHODS
Therapeutic drug monitoring request forms of psychiatric patients were screened retrospectively. The serum concentrations in relation to the daily doses [(C/D) (ng/ml/mg)] and the metabolic ratios (metabolite/drug) were compared intraindividually under normal (<5 mg/l) and pathological (>5 mg/l) condition by the Wilcoxon signed-rank test.


RESULTS
Elevated levels of CRP were not associated with a significant (P>0.05) increase in C/D for citalopram (2.4 ng/ml/mg vs. 2.85 ng/ml/mg, N=15) or in C/D for the active moiety of venlafaxine (1.76 ng/ml/mg vs. 1.68 ng/ml/mg, N=39), compared with normal CRP serum levels. No significant difference in the metabolic ratio was observed in both groups.


CONCLUSIONS
There was no major effect of inflammation on the metabolism of citalopram and venlafaxine. Because of the broad therapeutic indices of these 2 drugs, the drugs seem to be a good choice for the treatment of depression, even if an infection occurs.
Department of Psychiatry and Psychotherapy, University Medical Centre Mainz, Germany.
G
G
Hefner
Faculty of Pharmacy, Department of Pharmaceutics, University of Mansoura, Egypt.
M E E
ME
Shams
Department of Psychiatry, Psychosomatics and Psychotherapy, University Hospital of Würzburg, Germany.
S
S
Unterecker
Institute of Clinical Chemistry and Laboratory Medicine, University Medical Centre Mainz, Germany.
T
T
Falter
Department of Psychiatry and Psychotherapy, University Medical Centre Mainz, Germany.
C
C
Hiemke
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000928:Antidepressive Agents / Q000097:blood / Q000493:pharmacokinetics; D002097:C-Reactive Protein / Q000378:metabolism; D015283:Citalopram / Q000097:blood* / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood* / Q000150:complications; D008297:Male; D001523:Mental Disorders / Q000097:blood / Q000150:complications; D008875:Middle Aged; D010865:Pilot Projects; D012189:Retrospective Studies; D044967:Serum / Q000378:metabolism*; D000069470:Venlafaxine Hydrochloride / Q000097:blood* / Q000493:pharmacokinetics; D055815:Young Adult
D000928:Antidepressive Agents; D015283:Citalopram; D000069470:Venlafaxine Hydrochloride; D002097:C-Reactive Protein