Treatment of guanfacine toxicity with naloxone.

We describe a 4-year-old boy who presents to the emergency department with lethargy, bradycardia, and initial hypertension followed by hypotension due to guanfacine toxicity after ingestion of standard doses of the extended release formulation. This is the first case report to describe the use of naloxone to treat these symptoms and document improvements in level of consciousness, blood pressure, and heart rate associated with this therapy.