Dog with severe heart collapse after lamotrigine poisoning

Abstract

CASE DESCRIPTION A 2-year-old 5.1-kg (11.2-lb) sexually intact male Maltese was admitted because of vomiting and seizures after a known ingestion of up to 206 mg/kg (93.6 mg/lb) of lamotrigine (a commonly prescribed human antiepileptic medication) approximately 3 hours earlier. CLINICAL FINDINGS On presentation, the dog was having a seizure; however, the seizure stopped before interventional treatment, and the dog was obtunded, tachycardic, and hypertensive. Fluid therapy was initiated, and a bolus of injectable lipid emulsion (ILE) was administered. The dog's cardiovascular and mentation signs improved, and the dog was hospitalized for supportive care and monitoring. Hours later, the dog developed ventricular tachycardia that progressed to ventricular fibrillation, then cardiac arrest. TREATMENT AND OUTCOME Cardiopulmonary resuscitation, including defibrillation, was initiated. With no response after several minutes of resuscitation efforts, another bolus of ILE was administered, and the dog's heartbeat returned shortly thereafter, albeit with severe ventricular arrhythmias that were treated medically, including with sodium bicarbonate. The dog was discharged 48 hours later with no neurologic or cardiovascular abnormalities. Six months later, the owner reported that the dog was doing well and had no abnormalities. CLINICAL RELEVANCE To our knowledge, there are no previous case reports in veterinary medicine regarding the successful use of ILE to treat cardiac arrest secondary to lipophilic drug toxicoses nor the use of and physiologic response to sodium bicarbonate during treatment of lamotrigine toxicoses in dogs; therefore, findings in the dog of the present report may help other veterinarians treating similarly affected dogs in the future.