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N-Acetylcysteine (NAC)

Prescription
Mucolytic / Antidote / Antioxidant
Last reviewed 21 Apr 2026 · PetCare.AI Editorial Team
Species
Dog, Cat
Brands
3 available
Formulations
3

Mechanism of action

Provides cysteine for glutathione synthesis, replenishing hepatic glutathione stores depleted by acetaminophen toxicity or oxidative stress. Also directly scavenges reactive oxygen species and acts as a mucolytic by breaking disulfide bonds in mucoproteins.

At a glance

Class
Mucolytic / Antidote / Antioxidant
Schedule
Prescription
Storage
Store at room temperature; opened vials use within 96h (IV) or 48h (inhalation); turns pink/purple with air — still effective

Dosing

🐕

Dog

Time-critical for acetaminophen overdose — initiate within 8h of ingestion for m
Dose
30–70 mg/kg
Route
IV, PO
Frequency
Loading then maintenance q4–8h
🐈

Cat

Cats lack glucuronidation — acetaminophen rapidly causes fatal Heinz body anemia
Dose
Route
IV, PO
Frequency
Loading then maintenance q4h (toxicity) or q8h (supportive)
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 — 3

Strength
Strength
Strength

Storage

Store at room temperature; opened vials use within 96h (IV) or 48h (inhalation); turns pink/purple with air — still effective

Safety

Monitoring parameters

Hepatic enzymes (ALT, AST)Methemoglobin levelClinical improvementPCV/hematocrit (Heinz body anemia in cats)
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

Acetadote
Mucomyst
NAC

FAQs

Frequently asked questions

What is N-Acetylcysteine (NAC)?
N-Acetylcysteine (NAC) is a mucolytic / antidote / antioxidant used in pets. Provides cysteine for glutathione synthesis, replenishing hepatic glutathione stores depleted by acetaminophen toxicity or oxidative stress. Also directly scavenges reactive oxygen species and acts as a mucolytic by breaking disulfide bonds in mucoproteins.
What is N-Acetylcysteine (NAC) used for in pets?
N-Acetylcysteine (NAC) is used in veterinary medicine for: Time-critical for acetaminophen overdose — initiate within 8h of ingestion for m; Cats lack glucuronidation — acetaminophen rapidly causes fatal Heinz body anemia.
What is the N-Acetylcysteine (NAC) dose for dogs?
For dogs, N-Acetylcysteine (NAC) is typically dosed as follows — Time-critical for acetaminophen overdose — initiate within 8h of ingestion for m: 30–70 mg/kg IV/PO Loading then maintenance q4–8h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
What is the N-Acetylcysteine (NAC) dose for cats?
For cats, N-Acetylcysteine (NAC) is typically dosed as follows — Cats lack glucuronidation — acetaminophen rapidly causes fatal Heinz body anemia: undefined undefined IV/PO Loading then maintenance q4h (toxicity) or q8h (supportive). Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
Does N-Acetylcysteine (NAC) need a prescription?
Yes. N-Acetylcysteine (NAC) 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
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