Recurrence of Lamotrigine-Associated Rash With Rechallenge

Sir: Lamotrigine is a relatively new antiepileptic drug with possible efficacy in treatment-resistant bipolar disorder. Skin rashes of various kinds occurred in 10% of patients in controlled trials of lamotrigine and led to discontinuation of treatment in 2% of patients taking lamotrigine. Rash is more likely with higher starting doses, faster dose titrations, and concurrent treatment with valproic acid (possibly because valproic acid doubles lamotrigine blood levels).