Massive clonidine overdose in a paediatric patient due to a pharmacy compounding error and a primer on investigating suspected compounding errors.

An early childhood male (2-5 years) who was prescribed clonidine presented to the emergency department with altered mental status, bradycardia and hypertension after an accidental clonidine overdose traced to a pharmacy compounding error. The patient was admitted to the paediatric intensive care unit and developed paralytic ileus, which necessitated nasogastric tube placement. An investigation by the State Board of Pharmacy revealed that the error involved the use of clonidine powder instead of tablets during the compounding process, which resulted in a 1000-fold overdose. This case highlights key historical details a clinician should elicit to assess the likelihood of a compounding error. We outline here important steps for investigation and management when such an error is suspected.