‌N-Acetylcysteine

CAS No.:616-91-1

Molecular Formula:C₅H₉NO₃S

Molecular Weight:163.20

EINECS NO.: ‌211-806-2

Acetylcysteine (NAC) in Veterinary Medicine: Core Functions, Applications, and Guidelines

‌

‌I. Core Mechanisms and Therapeutic Effects‌

‌1. Detoxification and Hepatoprotection‌

‌Acetaminophen (Paracetamol) Poisoning‌

• ‌Mechanism‌: Replenishes glutathione (GSH) to neutralize toxic NAPQI metabolites, preventing hepatic necrosis.
• ‌Application‌: Emergency treatment for dogs/cats ingesting acetaminophen-containing medications (e.g., cold remedies).

‌Dosage‌: 70–140 mg/kg IV or orally, repeated every 4–6 hours.

• ‌Efficacy‌: >60% survival rate improvement if administered within 8 hours post-poisoning.

‌Heavy Metal and Toxin Clearance‌

• ‌Chelation‌: Binds lead/mercury via sulfhydryl (-SH) groups (often combined with EDTA).
• ‌Mycotoxin Detox‌: Reduces aflatoxin B1-induced liver damage in poultry (200 mg/kg NAC lowers ALT by 50%).

‌2. Respiratory Disease Management‌

‌Mucolytic and Expectorant Effects‌

• ‌Action‌: Breaks disulfide bonds in mucus, reducing viscosity and improving airflow.
• ‌Indications‌:
  • ‌Pets‌: Bronchitis, pneumonia (cough/dyspnea).
  • ‌Livestock‌: Bacterial/viral respiratory infections (e.g., swine enzootic pneumonia).
• ‌Administration‌:
  • Nebulization (3–5% solution) or oral (10–20 mg/kg BID).

‌Anti-inflammatory and Immunomodulatory Effects‌

• ‌Mechanism‌: Suppresses IL-6, TNF-α, and mitigates chronic inflammation (e.g., equine recurrent airway obstruction).

‌3. Antioxidant and Anti-stress Properties‌

‌Oxidative Stress Protection‌

• ‌Mechanism‌: Boosts intracellular GSH, scavenges free radicals, and protects cellular integrity.
• ‌Applications‌:
  • ‌Poultry‌: Heat stress mitigation (100 mg/kg NAC in feed improves egg production by 5–8%).
  • ‌Aquaculture‌: Reduces oxidative damage during transport/high-density farming.

‌Immune Enhancement‌

• Stimulates lymphocyte proliferation and enhances vaccine efficacy (e.g., swine fever vaccination).

‌III. Usage Precautions‌

‌Dosage Control‌:

• Overdose may cause vomiting/diarrhea (especially in monogastrics); slow IV infusion to avoid hypotension.
• Prepare NAC solutions fresh for poultry (rapid oxidation in water).

‌Drug Interactions‌:

Avoid concurrent use with oxidizers (e.g., potassium permanganate) or antibiotics (e.g., penicillin); administer 2 hours apart.

‌Regulatory Compliance‌:

• ‌EU‌: Approved for specific indications (e.g., detox) with residue limits in food animals.
• ‌China‌: Follow Regulations on the Administration of Veterinary Drugsand withdrawal periods.

‌IV. Research Advances and Potential Uses‌

• ‌Antiviral Adjunct‌: Inhibits PRRSV replication in vitro (50 μM effective concentration).
• ‌Reproductive Health‌: Improves semen quality in bulls (15% increase in sperm motility).

‌V. Summary‌

Acetylcysteine serves as a cornerstone in veterinary medicine for ‌detoxification, antioxidant support, and respiratory care‌, addressing poisoning emergencies, chronic diseases, and environmental stressors. Safe and effective application requires species-specific dosing, adherence to regulations, and tailored therapeutic strategies.