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Naloxone

Prescription

Opioid antagonist (pure mu, kappa, delta antagonist)

Last reviewed 19 Apr 2026 · PetCare.AI Editorial Team

Species

Dog, Cat

Brands

3 available

Interactions

2 documented

Formulations

Mechanism of action

Competitively binds all opioid receptor subtypes (mu, kappa, delta) with highest affinity for mu receptors, rapidly displacing opioid agonists and reversing their effects

At a glance

Class

Opioid antagonist (pure mu, kappa, delta antagonist)

Schedule

Prescription

Storage

Store below 25°C, protect from light

Dosing

🐕

Dog

Opioid reversal (respiratory depression, overdose)

Dose

0.01–0.04 mg/kg

Route

IV, IM, SC, Intranasal

Frequency

q2–3 min until effect; may need repeat doses

Max dose

2 mg/dose; 10 mg/day

Duration: Short-acting (30–90 min); re-narcotization possible

🐈

Cat

Opioid reversal

Dose

0.01–0.04 mg/kg

Route

IV, IM, SC

Frequency

q2–3 min until effect

Max dose

0.4 mg/dose; 2 mg/day

Duration: Short-acting; monitor for renarcotization

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

💉

Injection — 2

Strength

0.4mg/mL

Available in India

Strength

1mg/mL

Storage

Store below 25°C, protect from light

Safety

Absolute contraindications — do not use

Known hypersensitivity to naloxone

Use with caution

Opioid-dependent patients
May precipitate acute withdrawal and severe pain
Cardiac disease
Rapid reversal may cause catecholamine surge

Adverse effects

Common

Return of pain

Tachycardia

Excitement/dysphoria

Serious

Acute opioid withdrawal

Pulmonary edema (rare)

Cardiac arrhythmias

Seizures (rare)

Monitoring parameters

Respiratory rateHeart ratePain assessmentLevel of consciousnessMonitor for renarcotization (naloxone shorter acting than many opioids)

Educational reference only

Interactions

Minor — 2

Fentanyl

minor

Naloxone is a mu-opioid antagonist — reverses fentanyl effects (intentional use for overdose reversal)

Management: This is the intended use. Give naloxone IV to reverse fentanyl respiratory depression. Effect is shorter than fentanyl — may need repeat doses.

Butorphanol

minor

Naloxone reverses butorphanol's opioid effects (intended reversal agent)

Management: Standard reversal. Naloxone will reverse both sedation and analgesia.

Educational reference only

Brands

International

Narcan

Adapt Pharma

India

Nalox

Samarth

Nalone

Neon Labs

FAQs

Frequently asked questions

›What is Naloxone?

Naloxone is a opioid antagonist (pure mu, kappa, delta antagonist) used in pets. Competitively binds all opioid receptor subtypes (mu, kappa, delta) with highest affinity for mu receptors, rapidly displacing opioid agonists and reversing their effects

›What is Naloxone used for in pets?

Naloxone is used in veterinary medicine for: Opioid reversal (respiratory depression, overdose); Opioid reversal.

›What is the Naloxone dose for dogs?

For dogs, Naloxone is typically dosed as follows — Opioid reversal (respiratory depression, overdose): 0.01–0.04 mg/kg IV/IM/SC/Intranasal q2–3 min until effect; may need repeat doses. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.

›What is the Naloxone dose for cats?

For cats, Naloxone is typically dosed as follows — Opioid reversal: 0.01–0.04 mg/kg IV/IM/SC q2–3 min until effect. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.

›What are the side effects of Naloxone?

Common: Return of pain, Tachycardia, Excitement/dysphoria. Serious (call your vet immediately): Acute opioid withdrawal, Pulmonary edema (rare), Cardiac arrhythmias, Seizures (rare).

›Does Naloxone need a prescription?

Yes. Naloxone is a prescription medication and should only be administered under veterinary supervision.

›When should Naloxone not be used?

Do not use Naloxone if: Known hypersensitivity to naloxone.

Educational reference only

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

Related medicines

Other medicines in the same class (Opioid antagonist).

Naltrexone

Long-acting competitive antagonist at mu, kappa, and delta opioid receptors. Unlike naloxone, naltrexone has high oral bioavailability and long half-life (10–13h). Used for opioid dependence, compulsive behaviors, and pruritus.

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