Antimuscarinic Toxicity Safely Managed with High-Dose Transdermal Rivastigmine: A Case Report

C James Watson, Tufts University School of Medicine, Boston, Massachusetts.
Emilie M. Burrill, Maine Medical Center, Department of Emergency Medicine, Portland, Maine.
William S. Jaffee, Tufts University School of Medicine, Boston, Massachusetts.

Abstract

INTRODUCTION: Antimuscarinic toxicity, which can cause delirium and unsafe behavior, may result from an adverse effect of prescribed medications or from non-medical substance use. Physostigmine shortages have prompted use of transdermal rivastigmine for management of antimuscarinic toxicity; however, symptom control is equivocal at standard dosing. CASE REPORT: A patient with antimuscarinic toxicity was treated with physostigmine and transitioned to 26.6 milligrams/24 hours transdermal rivastigmine for sustained symptom control. He experienced no adverse effects and tolerated floor admission. DISCUSSION: There is mechanistic plausibility supporting safe, sustained control of antimuscarinic toxicity with high-dose transdermal rivastigmine. Central distribution is more rapid than serum distribution and higher doses correlate with a shorter time to peak concentration.