Abstract
Objective: The hypothesis of this study is that the efficacy of lamotrigine is related with blood level in bipolar disorder. Our aim is to compare the periods before and after lamotrigine use in cases with bipolar disorder and to investigate whether there has been any relation between lamotrigine blood level and clinical progress or not.
Method: For this aim, 40 consecutive cases diagnosed with bipolar disorder type I according to DSM-IV criteria, using lamotrigine for at least two years in combination with any mood-stabilizing agent such as lithium, anticonvulsants or atypical antipsychotics have been evaluated. The cases who applied to our outpatients’ clinic for their routine controls and who additionally accepted to participate to the study and gave informed consent have been included in the study. For the evaluation, being in remission period was set as a criterion for these cases. The interview for confirming the bipolar diagnosis was carried out by using SCID-I. The sections before and after maintenance treatment present in the SKIP-TURK Mood Disorders Diagnosis and Patient Registration Form were filled in together with the patients and their relatives. Blood samples were collected from the cases in order to analyze lamotrigine blood level.
Results: In bipolar cases, when the periods before and after long term maintenance treatment with lamotrigine were compared, it was determined that after using lamotrigine, total episode frequency and depressive episode frequency were decreased, episode severity was less severe (p<0.001, 0.039 and 0.04, respectively) and fast onset and termination ratios were decreased (p=0.027). When evaluated according to these variables, in long term maintenance the ratio of treatment response to lamotrigine among bipolar cases was 77.5%. In cases with treatment response to lamotrigine, lamotrigine blood levels were found to be higher (3.8±1.9/2.0±1.1 µg/ml) (p=0.005).
Conclusion: Lamotrigine is an efficient choice in long-term maintenance treatment of bipolar disorder and the relationship between this efficacy and the blood level should be supported with future studies.

Key words: lamotrigine, bipolar disorder, blood level