title: Severe sodium channel blockade and cardiovascular collapse due to a massive lamotrigine overdose.
abstract: BACKGROUND
  Cardiac arrest due to lamotrigine (LTG) has been reported after co-ingestion with bupropion, but severe sodium channel blockade in the absence of other toxins has not been described. We report a case of cardiac arrest and status epilepticus following a massive LTG overdose.
  
  
  METHODS
  A 48 year-old female was brought to the ED with seizure-like activity subsequent to ingesting 7.5 g of LTG. Vital signs were HR 131, BP 107/68, T 99.4°F, RR 16. She was intubated in the ED for a low GCS. Initial ECG demonstrated a narrow-complex normal sinus rhythm, and her labs were unremarkable. Three hours after intubation she developed status epilepticus, and a pulseless wide-complex tachycardia. She was aggressively resuscitated during which time pulses were periodically reestablished, but lost each time seizures recurred. She was not stabilized until the convulsions were terminated with vecuronium. Her post-resuscitation ECG demonstrated a junctional tachycardia with a 3 mm R-wave in aVR. The LTG level was 74.7 mcg/ml (therapeutic: 3-14 mcg/ml). Comprehensive LC-MS/MS drug screen was negative for all screened compounds.
  
  
  CONCLUSIONS
  This is the first report of cardiovascular collapse due to LTG with the highest drug concentration to date.
  
  
  CONCLUSIONS
  The degree of neurologic and cardiovascular toxicity seen in this case are novel and illustrate the potential for severe sodium channel blockade after massive LTG poisonings. Drug levels are not clinically relevant in the acute setting due to the time delay in obtaining results, and recurrent seizure activity may be the only clinical finding that precedes severe cardiac toxicity.
authors.affiliation: University of California San Diego, Division of Medical Toxicology, 200 West Arbor Drive, MC 8925, San Diego, CA 92103-8925, United States. joshnogar@gmail.com
authors.forename: Joshua N
authors.initials: JN
authors.lastname: Nogar
authors.forename: Alicia B
authors.initials: AB
authors.lastname: Minns
authors.forename: Davut J
authors.initials: DJ
authors.lastname: Savaser
authors.forename: Bihn T
authors.initials: BT
authors.lastname: Ly
mesh_terms: D002121:Calcium Channel Blockers / Q000009:adverse effects*; D062787:Drug Overdose / Q000150:complications* / Q000628:therapy; D005260:Female; D006323:Heart Arrest / Q000209:etiology*; D006801:Humans; D000077213:Lamotrigine; D008875:Middle Aged; D013226:Status Epilepticus / Q000209:etiology; D013610:Tachycardia / Q000209:etiology; D014227:Triazines / Q000009:adverse effects*
chemical_list: D002121:Calcium Channel Blockers; D014227:Triazines; D000077213:Lamotrigine