Rivastigmine to Prevent Recurrence of Antimuscarinic Delirium

Description

Antimuscarinic delirium (AMD) is a common and dangerous toxicology condition caused by poisoning by medications and other chemicals that block muscarinic receptors. Physostigmine is effective in reversing AMD but has a short duration of action, and patient commonly experience recurrence of AMD after initial control with physostigmine. Recent case reports and small observational studies suggest that rivastigmine, which has a longer duration of action than physostigmine, might be useful in the treatment of AMD. In order to investigate the effectiveness of rivastigmine in preventing recurrence of AMD after initial control with physostigmine, the investigators propose a randomized, placebo-controlled clinical trial of rivastigmine for AMD. The investigators hypothesize that patients treated with rivastigmine after initial control of AMD with physostigmine will experience less recurrence of antimuscarinic delirium than those treated with placebo.

Conditions

Anticholinergic Toxicity

Study Overview

Study Details

Study overview

Antimuscarinic delirium (AMD) is a common and dangerous toxicology condition caused by poisoning by medications and other chemicals that block muscarinic receptors. Physostigmine is effective in reversing AMD but has a short duration of action, and patient commonly experience recurrence of AMD after initial control with physostigmine. Recent case reports and small observational studies suggest that rivastigmine, which has a longer duration of action than physostigmine, might be useful in the treatment of AMD. In order to investigate the effectiveness of rivastigmine in preventing recurrence of AMD after initial control with physostigmine, the investigators propose a randomized, placebo-controlled clinical trial of rivastigmine for AMD. The investigators hypothesize that patients treated with rivastigmine after initial control of AMD with physostigmine will experience less recurrence of antimuscarinic delirium than those treated with placebo.

Rivastigmine to Prevent Recurrence of Antimuscarinic Delirium After Initial Control With Physostigmine (RIVA-AP): a Randomized, Placebo-controlled Trial

Rivastigmine to Prevent Recurrence of Antimuscarinic Delirium

Condition
Anticholinergic Toxicity
Intervention / Treatment

-

Contacts and Locations

Saint Louis

Washington University School of Medicine, Saint Louis, Missouri, United States, 63110

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

For general information about clinical research, read Learn About Studies.

Eligibility Criteria

  • * 10 years of age or older
  • * Diagnosis of antimuscarinic delirium by history and physical examination, in the opinion of the treating attending toxicologist.
  • * Treatment with physostigmine according to the local standard of care is planned or has been administered by the treating attending toxicologist and is acceptable to the patient's primary attending physician and surrogate decision maker.
  • * Antimuscarinic delirium is reasonably controlled after initial physostigmine treatment, as determined by treating toxicologist on bedside physical examination. (Patients may begin the screening and enrollment process prior to physostigmine administration, but will not undergo final initiation of study treatment until after response to physostigmine has been confirmed).
  • * Age less than 10 years at time of enrollment
  • * Surrogate decision maker not available to provide informed consent for enrollment.
  • * Patient is pregnant or a ward of the state.
  • * Inability to safely tolerate oral medication, in the judgement of the treating attending physician.
  • * Evidence of significant risk for serious cardiac or neurologic sequelae of antimuscarinic poisoning:
  • * Evidence of significant risk of adverse effect of AChE-I:
  • 1. Ages 10-12: HR \<84 beats per minute 2. Ages 12-15: HR \<78 beats per minute 3. Ages 15-18: HR \<73 beats per minute b. Known or suspected seizure disorder. c. History of asthma or COPD or wheezing during index presentation d. Known or suspected physical obstruction of intestinal or urogenital tract i. Ileus and/or urinary retention due to antimuscarinic poisoning do not exclude patients from enrollment.
  • * Any known allergy or intolerance to rivastigmine or other AChEI.
  • * Failure to achieve reasonable initial control of antimuscarinic delirium after physostigmine administration, as assessed by treating toxicologist on bedside physical examination.

Ages Eligible for Study

10 Years to

Sexes Eligible for Study

ALL

Accepts Healthy Volunteers

No

Collaborators and Investigators

Washington University School of Medicine,

Kevin Baumgartner, MD, PRINCIPAL_INVESTIGATOR, Washington University School of Medicine

Study Record Dates

2026-07