Rivastigmine as an alternative treatment for anticholinergic toxidrome in light of the physostigmine shortage: A case series

Abstract

Introduction

Physostigmine is an acetylcholinesterase inhibitor historically used for the treatment of anticholinergic toxicity. Supply of physostigmine has been limited as the US manufacturer recently stopped production. Rivastigmine, a long-acting acetylcholinesterase inhibitor FDA-approved for the treatment of Alzheimer's and Parkinson's disease dementia, is a potential alternative to physostigmine. There are few case reports and case series demonstrating the safe and effective use of both oral and transdermal rivastigmine for anticholinergic toxicity. The objective of this study was to describe the effects of rivastigmine in patients with anticholinergic toxicity.

Methods

A retrospective case review of patients that received rivastigmine at a metropolitan level-1 trauma center between January 2022–January 2024 resulted in 12 patients who met inclusion/exclusion criteria and were included in this analysis. Data collected included xenobiotic ingested, co-ingestions, symptoms on presentation, rivastigmine capsule and/or patch administration, adverse events, benzodiazepine administration, disposition, ICU and hospital length of stay.

Results

Of 12 patients, 9 had co-ingestions of other prescription or over-the-counter medications. 2 of 12 patients received both rivastigmine patches and capsules, 8 of 12 received only patches, and 2 of 12 received only capsules. The average dose of rivastigmine patches was 8.66 mg and average capsule dose was 6 mg. None of the patients experienced adverse effects from rivastigmine use. Length of stay ranged from 2 to 9 days with an average of 3.6 days.

Conclusion

Our study shows that rivastigmine is a reasonable alternative to physostigmine based on the lack of adverse events reported and symptom relief.