Physostigmine

Mechanism-of-action classes: Cholinergic Agonists; Cholinesterase Inhibitors.

• & USAGE To reverse the effect upon the central nervous system, caused by clinical or toxic dosages of drugs capable of producing the anticholinergic syndrome.

• Physostigmine Salicylate Injection should not be used in the presence of asthma, gangrene, diabetes, cardiovascular disease, mechanical obstruction of the intestine or urogenital tract or any vagotonic state, and in patients receiving choline esters and depolarizing neuromuscular blocking agents (decamethonium, succinylcholine). For post-anesthesia, the concomitant use of atropine with physostigmine salicylate is not recommended, since the atropine antagonizes the action of physostigmine.contraindicated

DOSAGE & ADMINISTRATION Past Anesthesia Care: 0.5 to 1.0 mg intramuscularly or intravenously. INTRAVENOUS ADMINISTRATION SHOULD BE AT A SLOW CONTROLLED RATE OF NO MORE THAN 1 MG PER MINUTE. Dosage may be repeated at intervals of 10 to 30 minutes if desired patient response is not obtained.

Contains sodium bisulfite, a sulfite that may cause allergic-type reactions including anaphylactic symptoms and life-threatening or less severe asthmatic episodes in certain susceptible people. The overall prevalence of sulfite sensitivity in the general population is unknown and probably low. Sulfite sensitivity is seen more frequently in asthmatic than in non-asthmatic people. If excessive symptoms of salivation, emesis, urination and defecation occur, the use of Physostigmine Salicylate Injection should be terminated. If excessive sweating or nausea occur, the dosage should be reduced. Intravenous administration should be at a slow, controlled rate, no more than 1 mg per minute (see DOSAGE . Rapid administration can cause bradycardia, hypersalivation leading to a respiratory difficulties and possible convulsions. An overdosage of Physostigmine Salicylate Injection can cause a cholinergic crisis.

Nausea, vomiting and salivation; can be offset by reducing dosage. Bradycardia and convulsions, if intravenous administration is too rapid. See DOSAGE AND ADMINISTRATION.

USAGE IN PRENANCY Safe use in pregnancy and lactation has not been established; therefore, use in pregnant women, nursing mothers or women who may become pregnant requires that possible benefits be weighed against possible hazards to mother and child.

Can cause a cholinergic crisis. Appropriate antidote is atropine sulfate.

1. 1Anticholinergic Syndrome240%
2. 2Neuromuscular Block Prolonged240%
3. 3Blood Creatine Phosphokinase Increased120%
4. 4Blood Potassium Increased120%
5. 5Bradycardia120%
6. 6Cardiac Arrest120%
7. 7Drug Ineffective120%
8. 8Hyperthermia Malignant120%
9. 9Myoglobin Blood Increased120%
10. 10Poor Quality Drug Administered120%
11. 11Product Quality Issue120%

Recent PubMed references pinned to Physostigmine as a MeSH major topic. Citations link to pubmed.ncbi.nlm.nih.gov.

• A phase 1, safety, tolerability, and pharmacokinetics study of bisnorcymserine, a highly selective inhibitor of butyrylcholinesterase.
  Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics · 2026 · Tzieras I, Manolopoulos A, Tweedie D, et al.
  PMID 42127455DOI 10.1016/j.neurot.2026.e00918
• Tropatepine poisoning and management: a series of 458 cases.
  Clinical toxicology (Philadelphia, Pa.) · 2026 · Tireau E, Descatha A, French PCC Research group, et al.
  PMID 41557478DOI 10.1080/15563650.2025.2605131
• Physostigmine modulates hippocampal GABAergic neurotransmission via α7 nicotinic acetylcholine receptors.
  Neuropharmacology · 2026 · Hernández-Abrego A, Vázquez-Gómez E, Mejía-Piedras J, et al.
  PMID 41326234DOI 10.1016/j.neuropharm.2025.110736
• Pharmacokinetics of Novel Crystalline Buntanetap in Mice, Dogs, and Humans.
  Biomolecules · 2025 · Morin A, Christie M, Damiano E, et al.
  PMID 41008606DOI 10.3390/biom15091299
• Post-injection delirium/sedation syndrome from long-acting olanzapine intramuscular injection is rapidly reversed with physostigmine and rivastigmine.
  Clinical toxicology (Philadelphia, Pa.) · 2025 · Fotheringham S, Buckley NA, Bradshaw C, et al.
  PMID 40889148DOI 10.1080/15563650.2025.2537806
• Rivastigmine as an alternative in physostigmine shortage for anticholinergic toxicity treatment.
  Regulatory toxicology and pharmacology : RTP · 2025 · Mehrpour O, Marini M, Nakhaee S, et al.
  PMID 40414273DOI 10.1016/j.yrtph.2025.105857
• Rivastigmine as an alternative treatment for anticholinergic toxidrome in light of the physostigmine shortage: A case series.
  The American journal of emergency medicine · 2025 · Berg M, Strand A, Garrett ND, et al.
  PMID 40288328DOI 10.1016/j.ajem.2025.04.047
• The decline in the clinical relevance of pilocarpine and physostigmine monitored in pharmacology textbooks from 1878 to 2023: nine take-home messages for future (pharmacology) textbook authors.
  Naunyn-Schmiedeberg's archives of pharmacology · 2025 · Ludwig L, Seifert R
  PMID 39531042DOI 10.1007/s00210-024-03558-x

The 10 most recently updated of 13 ClinicalTrials.gov registrations naming Physostigmine as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

• Rivastigmine to Prevent Recurrence of Antimuscarinic Delirium
  Suspended · Phase 2 · Interventional · 42 enrolled · Washington University School of Medicine
  NCT06399679updated 2026-06-04
• Acetylcholine, Tobacco Smoking, Genes and Nicotinic Receptors
  Completed · Interventional · 80 enrolled · Yale University
  NCT02008292updated 2023-10-25
• Treatment of Adolescent Antimuscarinic (Anticholinergic) Toxidrome
  Completed · Phase 4 · Interventional · 19 enrolled · University of Colorado, Denver
  NCT03090620updated 2021-08-23
• Anticholium® Per Se
  Completed · Interventional · 20 enrolled · University Hospital Heidelberg
  NCT03013322updated 2018-01-29
• Evaluation if Physostigmine Reduces Symptoms in Patients Who Has Developed a Delirium in Intensive Care After a Surgery
  Unknown · Phase 3 · Interventional · 120 enrolled · PD Dr. Bertram Scheller
  NCT02216266updated 2017-03-10
• Phamacological Reversal of Airway Instability During Sedation
  Completed · Interventional · 10 enrolled · University of Rochester
  NCT01171118updated 2015-04-27
• Pilot Study of Physostigmine-Enhanced Opioid Analgesia
  Completed · Phase 3 · Interventional · 20 enrolled · Medical University of Graz
  NCT01394445updated 2012-02-22
• Physostigmine After General Anesthesia
  Unknown · Interventional · 50 enrolled · Bispebjerg Hospital
  NCT00850850updated 2010-05-27
• The Effect of Physostigmine on Cognitive Functioning in the Immediate Period After Sedation for Colonoscopy
  Unknown · Interventional · 160 enrolled · Rabin Medical Center
  NCT01121497updated 2010-05-12
• Pharmacological Intervention in Insulin Resistance Targeting Autonomic Nerve Activity
  Completed · Early phase 1 · Interventional · 12 enrolled · AstraZeneca
  NCT00689208updated 2009-03-13

Frequently asked questions

How does Physostigmine work?

Mechanism-of-action classes: Cholinergic Agonists; Cholinesterase Inhibitors.

What is Physostigmine used for?

According to FDA labeling, Physostigmine carries indications including: & USAGE To reverse the effect upon the central nervous system, caused by clinical or toxic dosages of drugs capable of producing the anticholinergic syndrome.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.

What class of drug is Physostigmine?

Physostigmine is classified as Antidotes, Parasympathomimetics, Cholinergic Agonists, Cholinesterase Inhibitors, Pupillary Constriction.

What are the brand names for Physostigmine?

Physostigmine is marketed under brand names including Anticholium.

What are the contraindications for Physostigmine?

Physostigmine labeling lists contraindications including: Physostigmine Salicylate Injection should not be used in the presence of asthma, gangrene, diabetes, cardiovascular disease, mechanical obstruction of the intestine or urogenital tract or any vagotonic state, and in patients receiving choline esters and depolarizing neuromuscular blocking agents (decamethonium, succinylcholine). For post-anesthesia, the concomitant use of atropine with physostigmine salicylate is not recommended, since the atropine antagonizes the action of physostigmine.. Always consult the full prescribing information and a clinician.