Symptoms and signs: Acute ingestion of doses in excess of 10 to 20 times the maximum therapeutic dose of LAMICTAL have been reported, including fatal cases. Overdose has resulted in symptoms including nystagmus, ataxia, impaired consciousness, grand mal convulsion and coma. QRS broadening (intraventricular conduction delay) has also been observed in overdose patients. Broadening of QRS duration to more than 100 msec may be associated with more severe toxicity.
Treatment: In the event of overdosage, the patient should be admitted to hospital and given appropriate supportive therapy. Therapy aimed at decreasing absorption (activated charcoal) should be performed if indicated. Further management should be as clinically indicated. There is no experience with haemodialysis as treatment of overdose. In six volunteers with kidney failure, 20% of the LAMICTAL was removed from the body during a 4-hour haemodialysis session (see Pharmacology: Pharmacokinetics under Actions).