A patient with bipolar disorder starts lamotrigine and develops a mild macular rash after two weeks. There are no mucosal lesions or systemic symptoms. The most appropriate immediate step in management is to:

• A Continue the drug and add oral antihistamines
• B Discontinue the drug and avoid rechallenge ✓
• C Switch immediately to valproate
• D Increase the dose rapidly to achieve therapeutic levels

Explanation

Any rash developing during lamotrigine therapy, even if mild, warrants immediate discontinuation and avoidance of rechallenge because it can progress rapidly to Stevens-Johnson syndrome or toxic epidermal necrolysis. Slow dose titration reduces the risk, but once a rash appears, the drug must be stopped. Rapid dose escalation actually increases the risk of severe rash.

Reference: Katzung and Trevor's Pharmacology, 12th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.