Recruiting
Phase 2

Rivastigmine

Sponsor:

Washington University School of Medicine

Code:

NCT06382649

Conditions

Anticholinergic Toxicity

Eligibility Criteria

Sex: All

Age: 10+

Healthy Volunteers: Not accepted

Interventions

Rivastigmine

Placebo

Study Details

Brief summary:

Antimuscarinic delirium (AMD) is a common and dangerous toxicology condition caused by poisoning by medications and other chemicals that block muscarinic receptors. Physostigmine, the standard antidote for AMD, currently has very limited availability in the United States due to an interruption of production.

Recent case reports and small observational studies suggest that rivastigmine might be useful in the treatment of AMD, but there is not direct prospective evidence comparing rivastigmine to physostigmine or supportive care. In order to investigate the effectiveness of rivastigmine, the investigators propose a randomized, placebo-controlled clinical trial of rivastigmine for AMD. The investigators hypothesize that patients treated with rivastigmine for antimuscarinic delirium will experience more rapid resolution of agitation and delirium than those treated with placebo.

Conditions

Anticholinergic Toxicity

Study ID

NCT06382649

Start date

Jun, 2026

Status verified date

Jun, 2026

Completion date

Dec, 2028

Anticipated

Primary completion date

Nov, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 10+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • 10 years of age or older
  • Diagnosis of antimuscarinic delirium by history and physical examination, in the opinion of the treating attending toxicologist.
  • Reasonably likely to benefit from antidotal therapy for antimuscarinic delirium, as demonstrated by clinically significant agitation and delirium:

1. Richmond Agitation-Sedation Scale (RASS) of +1 or higher at the time of enrollment
2. Positive for delirium as defined by the Confusion Assessment Method for the ICU (CAM-ICU)

Exclusion Criteria:

  • 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:

a. Any known or suspected seizure activity prior to enrollment b. QRS duration >100 milliseconds on EKG at enrollment c. Any ventricular dysrhythmia prior to enrollment d. Respiratory failure of any etiology requiring endotracheal intubation e. Any hypotension at enrollment: i. Adults: systolic blood pressure (SBP) <90 mmHg ii. Children ≥10: systolic blood pressure (SBP) <90 mmHg, as per Pediatric Advanced Life Support (PALS) age-based cutoff for children 10 years of age or older3 f. Any administration of sodium bicarbonate, hypertonic saline, vasopressors, inotropes, antiarrhythmic agents, or intravenous lipid emulsion prior to enrollment.

g. Unacceptable risk of serious medical sequelae of antimuscarinic poisoning in the judgment of the treating attending toxicologist.
  • Evidence of significant risk of adverse effect of AChE-I:

a.Bradycardia or risk of AChE-I induced bradycardia at enrollment: i. Adults: heart rate (HR) <80 beats per minute ii. Children: heart rate below the median heart rate for age as proposed by Fleming et al.33:

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.

e. Known or suspected peptic ulcer disease.
  • Any known allergy or intolerance to rivastigmine or other AChEI.

Study Design

Enrollment

42 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Rivastigmine

Patients in the rivastigmine arm will receive rivastigmine 3mg by mouth once, followed by rivastigmine 1.5mg by mouth every 1 hour as needed for ongoing delirium or agitation (at the discretion of the treating physician), for up to three doses.

placebo comparator: Placebo

Patients in the placebo arm will receive oral placebo by mouth once, followed by oral placebo every 1 hour as needed for ongoing delirium or agitation (at the discretion of the treating physician), for up to three doses.

Interventions

Rivastigmine

Rivastigmine 3mg by mouth once, followed by rivastigmine 1.5mg by mouth every 1 hour as needed for ongoing delirium or agitation (at the discretion of the treating physician), for a maximum of three doses

Placebo

Matching oral placebo by mouth once, followed by placebo by mouth every 1 hour as needed for ongoing delirium or agitation (at the discretion of the treating physician), for a maximum of three doses

Primary outcome measure

  • Time to control of agitation and delirium [ Time Frame: Typically 8-36 hours after randomization ]

Central Contacts and Locations

Central contacts

Kevin Baumgartner, MD

3142731109baumgartner.k@wustl.edu

Locations

Washington University School of Medicine

Recruiting

St Louis, Missouri, United States, 63110

Contacts

Kevin Baumgartner

3142731109baumgartner.k@wustl.edu

More Information

Sponsor

Washington University School of Medicine

Last update posted

Jun 4, 2026

Last verified

Jun, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by Washington University School of Medicine on 2026-06-04.