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Atropine

PrescriptionCDSCO approved
Parasympatholytic / anticholinergic (muscarinic antagonist)
Last reviewed 19 Apr 2026 · PetCare.AI Editorial Team
Species
Dog, Cat
Brands
3 available
Interactions
1 documented
Formulations
3

Mechanism of action

Competitively blocks acetylcholine at muscarinic receptors, increasing heart rate (vagolytic), reducing secretions, dilating pupils, and relaxing smooth muscle

At a glance

Class
Parasympatholytic / anticholinergic (muscarinic antagonist)
Schedule
Prescription
Storage
Store below 25°C, protect from light
CDSCO (India)
Vet-approved — 1960-01

Dosing

🐕

Dog

Bradycardia (emergency)
Dose
0.02–0.04 mg/kg
Route
IV, IM, IT (intratracheal)
Frequency
May repeat every 3-5 minutes
Max dose
2 mg/dose; 6 mg/day
Duration: Until heart rate responds; max 3 doses
Pre-anaesthetic (anticholinergic)
Dose
0.02–0.04 mg/kg
Route
SC, IM
Frequency
Single dose
Max dose
2 mg
Duration: 15-30 min pre-induction
Organophosphate poisoning
Dose
0.1–0.5 mg/kg
Route
IV (1/4 dose) + IM (3/4 dose)
Frequency
Repeat every 10-15 min as needed
Max dose
20 mg/dose; 200 mg/day
Duration: Until muscarinic signs resolve (dry secretions)
🐈

Cat

Bradycardia (emergency)
Dose
0.02–0.04 mg/kg
Route
IV, IM
Frequency
May repeat every 3-5 minutes
Max dose
0.5 mg/dose; 1.5 mg/day
Duration: Until response; max 3 doses
Pre-anaesthetic
Dose
0.02–0.04 mg/kg
Route
SC, IM
Frequency
Single dose
Max dose
0.5 mg
Duration: 15-30 min pre-induction

Formulations

💉

Injectable — 2

Strength
0.6mg/mL
Available in India
Strength
1mg/mL
Available in India
🧴

Ophthalmic solution — 1

Strength
1%
Available in India

Storage

Store below 25°C, protect from light

Safety

Absolute contraindications — do not use

  • Tachycardia / tachyarrhythmias
    Atropine further increases heart rate — dangerous in existing tachycardia
  • Glaucoma
    Mydriasis increases intraocular pressure

Use with caution

  • GI obstruction / ileus
    Reduces GI motility — worsens ileus
  • Urinary obstruction
    Urinary retention effect

Adverse effects

Common
Tachycardia
Mydriasis
Xerostomia (dry mouth)
Decreased GI motility
Urinary retention
Serious
Sinus tachycardia/SVT
Ileus
Hyperthermia

Monitoring parameters

Heart rateECGPupil sizeGI motilityTemperature

Interactions

Moderate — 1

Dexmedetomidine
moderate
Atropine counters dexmedetomidine-induced bradycardia but may cause hypertension due to increased cardiac output against alpha-2 vasoconstriction
Management: Avoid routine atropine premedication with dexmedetomidine. Use only for clinically significant bradycardia.

Brands

International

Atropine Sulphate
Various

India

Tropine
Neon Labs
Atropin
Intas

FAQs

Frequently asked questions

›What is Atropine?
Atropine is a parasympatholytic / anticholinergic (muscarinic antagonist) used in pets. Competitively blocks acetylcholine at muscarinic receptors, increasing heart rate (vagolytic), reducing secretions, dilating pupils, and relaxing smooth muscle
›What is Atropine used for in pets?
Atropine is used in veterinary medicine for: Bradycardia (emergency); Pre-anaesthetic (anticholinergic); Organophosphate poisoning; Pre-anaesthetic.
›What is the Atropine dose for dogs?
For dogs, Atropine is typically dosed as follows — Bradycardia (emergency): 0.02–0.04 mg/kg IV/IM/IT (intratracheal) May repeat every 3-5 minutes; Pre-anaesthetic (anticholinergic): 0.02–0.04 mg/kg SC/IM Single dose; Organophosphate poisoning: 0.1–0.5 mg/kg IV (1/4 dose) + IM (3/4 dose) Repeat every 10-15 min as needed. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›What is the Atropine dose for cats?
For cats, Atropine is typically dosed as follows — Bradycardia (emergency): 0.02–0.04 mg/kg IV/IM May repeat every 3-5 minutes; Pre-anaesthetic: 0.02–0.04 mg/kg SC/IM Single dose. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›What are the side effects of Atropine?
Common: Tachycardia, Mydriasis, Xerostomia (dry mouth), Decreased GI motility, Urinary retention. Serious (call your vet immediately): Sinus tachycardia/SVT, Ileus, Hyperthermia.
›Does Atropine need a prescription?
Yes. Atropine is a prescription medication and should only be administered under veterinary supervision.
›When should Atropine not be used?
Do not use Atropine if: Tachycardia / tachyarrhythmias; Glaucoma.

References

References

Textbooks & handbooks

  • Plumb, D.C. Plumb's Veterinary Drug Handbook. 10th ed., Wiley-Blackwell, 2023.
  • Vail, D.M., Thamm, D.H., & Liptak, J.M. (eds.). Withrow & MacEwen's Small Animal Clinical Oncology. 6th ed., Saunders/Elsevier, 2020.
  • Riviere, J.E., & Papich, M.G. (eds.). Veterinary Pharmacology and Therapeutics. 10th ed., Wiley-Blackwell, 2018.
  • National Research Council. Nutrient Requirements of Dogs and Cats. National Academies Press, Washington DC, 2006.
  • The Merck Veterinary Manual. Merck & Co., Online edition. https://www.merckvetmanual.com/

Clinical guidelines & consensus

  • Fletcher, D.J., Boller, M., Brainard, B.M., et al. "RECOVER Evidence and Knowledge Gap Analysis on Veterinary CPR." Journal of Veterinary Emergency and Critical Care, 2012;22(S1):S102–S131.
  • American Animal Hospital Association. 2018 AAHA Diabetes Management Guidelines for Dogs and Cats. AAHA Press.

Journals & peer-reviewed studies

  • Hogan, D.F., Fox, P.R., Jacob, K., et al. "Secondary prevention of cardiogenic arterial thromboembolism in the cat: The FAT CAT study." Journal of Veterinary Cardiology, 2015;17(Suppl 1):S306–S317.
  • Boswood, A., Häggström, J., Gordon, S.G., et al. "Effect of Pimobendan in Dogs with Preclinical Myxomatous Mitral Valve Disease and Cardiomegaly: The EPIC Study — A Randomized Clinical Trial." Journal of Veterinary Internal Medicine, 2016;30(6):1765–1779.
  • ASPCA Animal Poison Control Center. Toxicology and Poison Management Guidelines. American Society for the Prevention of Cruelty to Animals. https://www.aspca.org/pet-care/animal-poison-control

Regulatory & approvals

  • Central Drugs Standard Control Organisation (CDSCO), Government of India. Veterinary Drug Approval Registry, 1969–2026. Directorate General of Health Services. https://cdsco.gov.in/

Databases

  • Washington State University, College of Veterinary Medicine. Veterinary Clinical Pharmacology Laboratory (VCPL) — MDR1 Multidrug Sensitivity Database. https://vcpl.vetmed.wsu.edu/
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 →