Selective Serotonin-reuptake Inhibitor (SSRI) has been the first choice drug for the treatment of depression, but there are many people that should be select another drug, for example, tricyclic antidepressant (TCA). Though there were various trials underwent in the purpose of predict to antidepressant effect in the different view point, there was no established method that could be available in clinical use.
We investigated 58 patients being treated with fluvoxamine (FLV) for 12 weeks, and analyzed the correlation between clinical effect of FLV and characteristics of depression, characteristics of pharmacokinetics of FLV (cf. plasma levels of FLV), characteristics of pharmacodynamics of FLV (cf. 5-HTTLPR).
Result of our study, there was "enough plasma concentration" of FLV, we found that the prediction used by plasma level of FLV was more available than that used by FLV dosage. Further, we found that there are much individual differences in dosage established "enough plasma concentration" of FLV, and that CYP2D6 polymorphism and CYP1A2 activity induced by smoking might be useful for predicting this individual differences.
On the other hand, there is no significantly correlation between 5-HTTLPR and antidepressant effect of FLV.
It will be necessary in the future to conduct studies involving larger numbers of patients.