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Paroxetine

Prescription
Selective Serotonin Reuptake Inhibitor (SSRI)
Last reviewed 21 Apr 2026 · PetCare.AI Editorial Team
Species
Dog, Cat
Brands
2 available
Interactions
3 documented
Formulations
2

Mechanism of action

Most potent and selective SSRI that blocks serotonin reuptake transporter (SERT), increasing serotonergic neurotransmission. Also has mild anticholinergic and norepinephrine reuptake inhibition. Used for anxiety, compulsive disorders, and aggression.

At a glance

Class
Selective Serotonin Reuptake Inhibitor (SSRI)
Schedule
Prescription
Storage
Store at room temperature below 30°C

Dosing

🐕

Dog

Used for separation anxiety, noise phobias, compulsive disorders, and fear-based
Dose
0.5–2 mg/kg
Route
PO
Frequency
q24h
🐈

Cat

Used for urine spraying, inappropriate elimination, intercat aggression, and anx
Dose
0.5–1.5 mg/kg
Route
PO
Frequency
q24h

Formulations

💊

Other — 2

Strength
—
Strength
—

Storage

Store at room temperature below 30°C

Safety

Monitoring parameters

Behavioral response at 4–8 weeksBody weightGI toleranceSeizure activity

Interactions

Contraindicated — 1

Selegiline (L-Deprenyl)
contraindicated
SSRI + MAO inhibitor: serotonin syndrome — hyperthermia, seizures, rigidity, death.
Management: NEVER combine. Allow 2-week washout of paroxetine before selegiline.

Major — 2

Tramadol
major
Paroxetine potently inhibits CYP2D6, blocking tramadol conversion to active metabolite M1 (reduced analgesia) while increasing serotonin syndrome risk.
Management: Avoid. Paroxetine renders tramadol ineffective as analgesic while increasing toxicity risk.
Codeine
major
Paroxetine is the most potent CYP2D6 inhibitor among SSRIs. Completely blocks codeine conversion to morphine.
Management: Codeine will be ineffective. Use direct-acting opioid instead.

Brands

Other markets

Paxil
Brisdelle

FAQs

Frequently asked questions

›What is Paroxetine?
Paroxetine is a selective serotonin reuptake inhibitor (ssri) used in pets. Most potent and selective SSRI that blocks serotonin reuptake transporter (SERT), increasing serotonergic neurotransmission. Also has mild anticholinergic and norepinephrine reuptake inhibition. Used for anxiety, compulsive disorders, and aggression.
›What is Paroxetine used for in pets?
Paroxetine is used in veterinary medicine for: Used for separation anxiety, noise phobias, compulsive disorders, and fear-based; Used for urine spraying, inappropriate elimination, intercat aggression, and anx.
›What is the Paroxetine dose for dogs?
For dogs, Paroxetine is typically dosed as follows — Used for separation anxiety, noise phobias, compulsive disorders, and fear-based: 0.5–2 mg/kg PO q24h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›What is the Paroxetine dose for cats?
For cats, Paroxetine is typically dosed as follows — Used for urine spraying, inappropriate elimination, intercat aggression, and anx: 0.5–1.5 mg/kg PO q24h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›Does Paroxetine need a prescription?
Yes. Paroxetine is a prescription medication and should only be administered under veterinary supervision.

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 →

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