Treatment of Anticholinergic Delirium with Oral Rivastigmine: A Case Report

Abstract

BackgroundAnticholinergic toxicity is commonly encountered in the emergency department. However, the availability of physostigmine, a central acetylcholinesterase inhibitor used to reverse anticholinergic delirium, has been significantly limited due to national drug shortages in the United States. Several articles have explored the viability of rivastigmine as an alternative treatment for these patients. Case ReportA 33-year-old male presented to the emergency department after a suspected suicide attempt. The patient was found with an empty bottle of diphenhydramine at the scene. On arrival, he was tachycardic, delirious, with dilated and nonreactive pupils and dry skin. As the clinical picture was highly suggestive of anticholinergic toxicity, the patient was treated with oral rivastigmine at a starting dose of 4.5mg to reverse his anticholinergic delirium. Though requiring a repeat dose, his delirium resolved without recurrence.Why Should an Emergency Physician Be Aware of This? Oral rivastigmine has been successfully applied here and in other case reports to reverse anticholinergic delirium with the benefit of prolonged agitation control. Emergency physicians may consider this medication in consultation with a specialist, with initial doses starting at 4.5 to 6 mg, if encountering anticholinergic delirium when physostigmine is not available.