Goal of the study was to evaluate the efficacy of paroxetine treatment in female patients with mental bulimia (MB) while monitoring CYP2D6 activity.

The study included 17 patients diagnosed with bulimia, 2 of whom dropped out. To date, results have been available for the first ten patients. EM (extensive metabolizers) phenotype was identified in 8 out of the 10 patients prior to paroxetine therapy; the remaining 2 patients were UM (ultra-extensive metabolizers). After 6 weeks of paroxetine therapy both patients with the initial UM phenotype had converted to EM. Out of the 8 bulimic patients phenotyped as EM, 6 converted to PM (poor metabolizers) status while 2 patients retained the EM phenotype. The 6-week paroxetine therapy improved the eating behaviour of patients who showed phenotype change from EM to PM or from UM to EM measured on the EAT scale. The global EAT score decrease was 16 points at EM/PM patients and 6 points at UM/EM case. This phenomenon may partly be explained by the greater availability of the medication substance in slower metabolization. Another piece of evidence supporting the hypothesis is the fact that neither improvement nor worsening of eating behaviour on the same scale (EAT) was observed in bulimic patients whose phenotype remained unchanged.

The study has been supported by the grant of the Ministry of Education, Youth and Sports No. 0021622404.