Abstracts

Rationale: Cross-sensitivity concerning skin reactions from antiepileptic drugs (AEDs) is a considerable clinical problem. In this study we wanted to investigate the pattern of cross-reaction among the current aromatic drugs, with a focus on lamotrigine. Methods: A retrospective survey of medical records concerning all AED treatment in consecutive patients with epilepsy was performed. Results: Altogether 663 patients were included comprising 2567 exposures to AEDs. Skin reactions occurred in 93 patients; and sequential rashes related to aromatic drugs in 17. Phenytoin (PHT), carbamazepine (CBZ) and oxcarbazepine (OCBZ) caused rashes in the range of 27-35% in patients with a history of another AED-related rash, whereas lamotrigine (LTG) caused another rash in only 17%. A history of an AED-related rash was a highly significant risk factor for reactions to PHT, CBZ, and OCBZ (p<0.001), but not for LTG (p=0.05). A CBZ rash was not a significant risk factor for an LTG reaction, and vice versa. Conclusions: LTG appears to be involved in cross-reactions less often than CBZ, OCBZ and PHT.