Generally, the present invention relates to lamotrigine analogs that have substituents at the triazine 3-position and on the benzene 4-position and 5-position. The lamotrigine analogs can include immunogenic moieties that can be used to prepare anti-lamotrigine antibodies, or antigenic moieties that can be used in immunodiagnostic assays for lamotrigine. Also, the lamotrigine analog can include tracer moieties for detecting the presence or amount of the analog during an immunodiagnostic assay. Additionally, the lamotrigine analogs can be used in immunodiagnostic assays to compete with lamotrigine for binding with anti-lamotrigine antibodies.