Dermatology Precautions and Slower Titration Yield Low Incidence of Lamotrigine Treatment-Emergent Rash

Objective: To assess treatment-emergent rash incidence when using dermatology precautions (limited antigen exposure) and slower titration during lamotrigine initiation.

Method: We assessed rash incidence in 100 patients with DSM-IV bipolar disorder instructed, for their first 3 months taking lamotrigine, to avoid other new medicines and new foods, cosmetics, conditioners, deodorants, detergents, and fabric softeners, as well as sunburn and exposure to poison ivy/oak. Lamotrigine was not started within 2 weeks of a rash, viral syndrome, or vaccination. In addition, lamotrigine was titrated more slowly than in the prescribing information. Patients were monitored for rash and clinical phenomena using the Systematic Treatment Enhancement Program for Bipolar Disorder Clinical Monitoring Form. Descriptive statistics were compiled.

Results: No patient had serious rash. Benign rash occurred in 5 patients (5%) and resolved uneventfully in 3 patients discontinuing and 2 patients continuing lamotrigine. Two patients with rash were found to be not adherent to dermatology precautions. Therefore, among the remaining patients, only 3/98 (3.1%) had benign rashes.

Conclusion: The observed rate of benign rash was lower than the 10% incidence in other clinical studies. The design of this study confounds efforts to determine the relative contributions of slower titration versus dermatology precautions to the low rate of rash. Systematic studies are needed to confirm these preliminary findings, which suggest that adhering to dermatology precautions with slower titration may yield a low incidence of rash with lamotrigine.