Misdiagnosis of lamotrigine toxicity as posterior circulation transient ischemic attack or stroke.

Purpose: Lamotrigine (LTG) is one of the most used antiseizure medications (ASMs). Titration is indicated for incomplete seizure control, but toxicity with vertigo, ataxia, and diplopia may ensue. Lamotrigine concentration would be the optimal diagnostic test.

Conversion from immediate-release to extended-release lamotrigine improves seizure control.

Background: Immediate release lamotrigine (LTG-IR) dosing can be limited by peak toxicity. It is thought that peak levels are responsible for some adverse effects such as dizziness, blurred vision, double vision and unsteadiness. At the same time, trough levels may be associated with reduced seizure threshold.