(867) Early and Aggressive: High-Dose Naloxone in Pediatric Tizanidine Overdose

Introduction: Included in pediatric “One Pill Can Kill” literature, Alpha-2 Agonists are commonly prescribed for neurologic, cardiovascular, and musculoskeletal conditions. With overdose, symptoms range from mild somnolence to complete cardiopulmonary collapse. Without specific antidotes, supportive care is the mainstay of management. However, given risk of rapid deterioration in pediatric patients, early and aggressive intervention is preferred. Naloxone is a short-acting opioid antagonist with evidence of efficacy in alpha-2 agonist toxicity and can prevent the need for more advanced cardiac and airway interventions.

Description: A 20-month-old male presented 1 hour after witnessed ingestion of 12-16mg tizanidine. He developed somnolence within 30 minutes following ingestion that progressed to obtundation and required bag-valve mask ventilation by EMS with an initial GCS of 7. Vital signs showed sinus bradycardia in the 80-90s and periods of apnea without stimulation. Physical exam showed borderline miosis with sluggish pupils. Labs were grossly normal and toxicologic workup showed no evidence of any co-ingestions. While preparing for intubation, Naloxone 0.1mg/kg was given IV push. This resulted in improvement in mental status and resolution of prolonged apnea, and intubation could be avoided. However, the response waned after about 30 minutes, and a Naloxone infusion was started. The patient was admitted to the PICU for monitoring and continued infusion until a complete return to baseline, with discharge shortly thereafter.

Discussion: While not fully recognized as a first-line intervention for the alpha-2 agonist toxidrome, naloxone is a cheap, common, and safe medication with straightforward dosing that may prevent the need for more advanced cardio-pulmonary support without delaying the preparation of those interventions. This is especially relevant to EMS and community hospitals, where critically ill pediatric patients may be rare, and the added stressor of weight-based preparation of multiple high-risk airway and medical interventions can lead to fatal errors, especially if transfer to a dedicated Pediatric Hospital is delayed or unavailable.