P0300 - Severe clonidine overdose requiring ICU: a pediatric emergency department case report

Background: Clonidine is a recommended therapy for the treatment of attention deficit hyperactive disorder in children. As a result of this use in the pediatric population, there is widespread availability of clonidine, and unintentional overdoses occur. Major toxic effects of clonidine include respiratory depression, hypotension, bradycardia, decreased cardiac output, and death. Review of the literature finds that few massive ingestions progressed to respiratory depression and apnea, requiring intubation and ventilatory assistance. Naloxone has been used at high dose(0.8-2mg/kg) to reverse the clonidine toxic effects. Published studies provide no data on dosage response, toxicodynamic response in overdose, or other critical areas that might help guide the clinician.

Case Description: A 2-year-old male with no significant past medical history presented to the pediatric emergency department with altered mental status after accidental clonidine ingestion. The patient took 6-12 pills of 0.05 mg tabs Clonidine (brother's prescription). Shortly after ingestion, the patient was moaning, less responsive to verbal stimuli, and with decreased tone. No reported apnea or other respiratory symptoms were reported. The patient’s mother immediately called 911 and the patient was taken to the ED. Vital signs on arrival showed a heart rate of 96 bpm, blood pressure of 136/63 mmHg, mean arterial pressure of 87, respiratory rate of 26 bpm, and physical exam was significant for altered mentation. Poison control was contacted and assisted in directing therapy. Baseline labs were unremarkable and EKG was significant for sinus bradycardia. Based on child’s progressively worsening somnolence and bradycardia, the patient was treated with 0.1 mg/kg (1.3mg/dose) of Naloxone every 3-5 minutes for a total of eleven doses. The patient heart rate and mentation status would temporarily improve after administration of naloxone and thus why a total of 11 doses were administered until the decision was made to place the patient on a naloxone drip (1mg/hour). Furthermore, the patient did have persistent bradycardia and one dose of atropine (0.25 mg) was given. The patient stabilized and was admitted to PICU for close cardio-respiratory monitoring.

Discussion: By the next day, the patient became more alert, awake, and asking for food. He completed 14 hours of IV fluids and naloxone drip (1mg/hour) before discontinuation. He remained hemodynamically stable and returned to his baseline behavior. He was discharged 24 hours after his ingestion.

Conclusion: This case report presents an example of successful treatment of clonidine overdose in the pediatric ED and PICU with naloxone and atropine. The results of this case are similar to previous reports. Current approaches include high-dose naloxone (0.8-2 mg/kg), based on case reports, since controlled clinical studies are lacking. Our case study, along with the small body of evidence, supports the idea that Naloxone should be attempted in pediatric patients with clonidine massive ingestion.