Rash in adult and pediatric patients treated with lamotrigine.

Data from clinical trials with lamotrigine indicate that the risk of serious rash in pediatric patients is higher than in adults. The incidence of rash associated with hospitalization among adults treated with lamotrigine is 0.3% and among pediatric patients 1.0%. The incidence of cases reported as possible Stevens-Johnson syndrome is 0.1% for adult patients and 0.5% for pediatric patients. These rates reflect lamotrigine dosing and concomitant AEDs used in these trials, both of which are risk factors for rash. Since many of the trials were conducted prior to the establishment of the current dosing recommendations, the incidence of serious rash in clinical trials does not necessarily reflect the incidence to be expected with use of current dosing recommendations. The higher incidence of serious rash in pediatric patients may at least partially be accounted for by the differential effects of the risk factors of dosing and concomitant use of valproic acid in these patients.