Effects of clomipramine on plasma amino acids and serotonergic parameters in panic disorder and depression.
We examined the effects of long-term (six months) treatment with the serotonin potentiating tricyclic antidepressant clomipramine on several serotonergic parameters in panic disorder and depressive patients. Serotonin (5-HT) levels in blood, platelets and plasma were significantly reduced to 4%, 3% and 28% of their respective baseline values. In addition, the plasma level of tryptophan was also significantly reduced, although the decrease was only 16%. Three months after discontinuation of clomipramine treatment, 5-HT in blood and platelets reached baseline values again, while the plasma 5-HT level was still reduced to 68% of pretreatment values. Unexpectedly, the plasma tryptophan concentration was even lower at this time-point than after six months of treatment. These results show that clomipramine not only has an effect on 5-HT levels in blood, platelets and plasma, but also on plasma tryptophan concentration. We speculate that low plasma tryptophan after treatment may constitute a risk for the recurrence of psychopathology.
Fekkes
D
D
Section Pathophysiology of Behaviour, Erasmus University, Rotterdam, The Netherlands.
Timmerman
L
L
Pepplinkhuizen
L
L
D000328:Adult; D000596:Amino Acids / Q000097:blood*; D000929:Antidepressive Agents, Tricyclic / Q000494:pharmacology* / Q000627:therapeutic use*; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism; D002997:Clomipramine / Q000494:pharmacology* / Q000627:therapeutic use*; D003866:Depressive Disorder / Q000097:blood / Q000188:drug therapy* / Q000378:metabolism*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D016584:Panic Disorder / Q000097:blood / Q000188:drug therapy* / Q000378:metabolism*; D011569:Psychiatric Status Rating Scales; D012701:Serotonin / Q000097:blood / Q000378:metabolism*; D014364:Tryptophan / Q000097:blood; D014443:Tyrosine / Q000097:blood
D000596:Amino Acids; D000929:Antidepressive Agents, Tricyclic; D012701:Serotonin; D014443:Tyrosine; D014364:Tryptophan; D002997:Clomipramine