Massive Lamotrigine Intoxication Refractory to Sodium Bicarbonate Treatment

Area of Science:

• Toxicology
• Pharmacology
• Emergency Medicine

Background:

• Acute lamotrigine (LTG) overdose can lead to severe complications including cardiac arrhythmias, hypotension, altered mental status, and seizures.
• This case report details a patient with massive LTG intoxication unresponsive to standard sodium bicarbonate treatment.

Purpose of the Study:

• To present a case of massive lamotrigine intoxication refractory to sodium bicarbonate.
• To evaluate the efficacy of intravenous lipid emulsion (ILE) as a rescue therapy for severe lamotrigine overdose.

Main Methods:

• A patient with massive lamotrigine overdose was treated with sodium bicarbonate and supportive measures.
• Intravenous lipid emulsion (ILE) was administered due to refractory neurological and cardiac symptoms.
• Serum drug concentrations, including lamotrigine, were monitored using liquid chromatography-tandem mass spectrometry.
• Pharmacokinetic analysis of lamotrigine half-life before and after ILE administration was performed.

Main Results:

• The patient presented with nonsustained ventricular tachycardia, QRS widening (160 ms), and coma (GCS 5).
• Initial serum lamotrigine level was 63 mg/L, peaking at 127 mg/L with a half-life of 48.5 hours.
• Following ILE administration, significant neurological and cardiac improvement was observed, with QRS narrowing and a reduced lamotrigine half-life of 10.5 hours.
• The patient was discharged from the ICU on day 15.

Conclusions:

• Intravenous lipid emulsion (ILE) serves as a viable rescue therapy for severe lamotrigine intoxication refractory to sodium bicarbonate.
• Therapeutic drug monitoring and prompt administration of ILE are crucial for managing refractory cases.
• Further research and case reporting are needed to solidify evidence-based management strategies for lamotrigine overdose.