Authors: Wong ICK, et al. Title: Factors influencing the incidence of lamotrigine-related skin rash. Reference: Ann Pharmacother 1999;33:1037-42. Purpose: To determine the incidence of and risk factors for lamotrigine-related rash. Study design: Retrospective, case record survey at five epilepsy referral centers in the UK (December 1993 to September 1996). Follow up: Not applicable. Patients: 1,050 epilepsy patients. Treatment: Lamotrigine 6.25–100 mg/day (mean range of the starting dose). Results: A significant reduction in the incidence of serious rash, from 1.5% to 0%, occurred after the starting dose was reduced in 1994 following recommendation by the manufacturer. Concurrent sodium valproate and a high starting daily dosage increased the risk of rash.