Home/Medicines/Physostigmine
All medicines

Physostigmine

Prescription
Reversible Acetylcholinesterase Inhibitor (Carbamate)
Last reviewed 21 Apr 2026 · PetCare.AI Editorial Team
Species
Dog, Cat
Brands
1 available
Formulations
1

Mechanism of action

Tertiary amine carbamate that crosses the BBB and reversibly inhibits acetylcholinesterase in both peripheral and central nervous system. Used as antidote for anticholinergic toxicity (atropine, antihistamine, TCA overdose).

At a glance

Class
Reversible Acetylcholinesterase Inhibitor (Carbamate)
Schedule
Prescription
Storage
Store at room temperature; protect from light

Dosing

🐕

Dog

Antidote for anticholinergic syndrome (mydriasis, tachycardia, agitation, urinar
Dose
0.02–0.06 mg/kg
Route
IV (slow)
Frequency
q15–30 min (repeat as needed)
🐈

Cat

Same anticholinergic toxicity antidote use
Dose
0.02–0.04 mg/kg
Route
IV
Frequency
q15–30 min
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

Formulations

💊

Other — 1

Strength

Storage

Store at room temperature; protect from light

Safety

Monitoring parameters

Heart ratePupil size (miosis expected)Respiratory effortLevel of consciousnessHave atropine ready as reversal
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

Interactions

No documented interactions.

Brands

Other markets

Antilirium

FAQs

Frequently asked questions

What is Physostigmine?
Physostigmine is a reversible acetylcholinesterase inhibitor (carbamate) used in pets. Tertiary amine carbamate that crosses the BBB and reversibly inhibits acetylcholinesterase in both peripheral and central nervous system. Used as antidote for anticholinergic toxicity (atropine, antihistamine, TCA overdose).
What is Physostigmine used for in pets?
Physostigmine is used in veterinary medicine for: Antidote for anticholinergic syndrome (mydriasis, tachycardia, agitation, urinar; Same anticholinergic toxicity antidote use.
What is the Physostigmine dose for dogs?
For dogs, Physostigmine is typically dosed as follows — Antidote for anticholinergic syndrome (mydriasis, tachycardia, agitation, urinar: 0.02–0.06 mg/kg IV (slow) q15–30 min (repeat as needed). Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
What is the Physostigmine dose for cats?
For cats, Physostigmine is typically dosed as follows — Same anticholinergic toxicity antidote use: 0.02–0.04 mg/kg IV q15–30 min. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
Does Physostigmine need a prescription?
Yes. Physostigmine is a prescription medication and should only be administered under veterinary supervision.
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

References

References

The PetCare.AI drug reference is built from 13 authoritative sources cited across 580 drug monographs.

Textbooks & handbooks — 5

  • Plumb's Veterinary Drug Handbook
  • Withrow & MacEwen's Small Animal Clinical Oncology
  • Merck Veterinary Manual
  • NRC Nutrient Requirements of Dogs and Cats
  • Veterinary Pharmacology and Therapeutics (Riviere & Papich)

Clinical guidelines & consensus — 4

  • ASPCA Animal Poison Control Center Guidelines
  • AAHA Diabetes Management Guidelines
  • ASPCA Poison Control Guidelines
  • RECOVER CPR Guidelines

Journals & peer-reviewed studies — 2

  • EPIC Study (J Vet Intern Med 2016)
  • JVIM FAT CAT Study

Regulatory & approvals — 1

  • CDSCO Veterinary Drug Approval Registry (1969–2026)

Databases — 1

  • Washington State University VCPL MDR1 Database
Need help? 💬
Chat with us on WhatsApp