Home/Medicines/Paroxetine

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

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

Frequency

q24h

🐈

Cat

Used for urine spraying, inappropriate elimination, intercat aggression, and anx

Dose

0.5–1.5 mg/kg

Route

Frequency

q24h

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 — 2

Strength

—

Strength

—

Storage

Store at room temperature below 30°C

Safety

Monitoring parameters

Behavioral response at 4–8 weeksBody weightGI toleranceSeizure activity

Educational reference only

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.

Educational reference only

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.

Educational reference only