Acetylcysteine

Mucolytic via nebulization for respiratory secretions in horses and small animals; uterine lavage/infusion for equine endometritis; acetaminophen overdose antidote; meconium impaction retention enema in foals. Mucolytic agent and antioxidant precursor. Mechanism: free sulfhydryl groups cleave disulfide bonds in mucoproteins, reducing mucus viscosity. Also replenishes intracellular glutathione (antioxidant); serves as N-acetylcysteine (NAC) antidote for acetaminophen overdose by restoring hepatic glutathione stores. Available as 10% and 20% solutions for nebulization or IV use. Key information Refrigerate oral solution after opening; use within 96 hours. Antidote for acetaminophen toxicity — loading dose critical within 8 hours of ingestion. Nebulization solution may cause bronchospasm — pretreat with bronchodilator. Incompatible with many metals and rubber; use plastic or glass equipment.

IV (NAC antidote): dilute in D5W or 0.9% NaCl; administer loading dose over 15–60 min, then maintenance dose by CRI. Nebulization: dilute 10% or 20% solution 1:1 with sterile saline; nebulize 10–15 min q8–12h. Pre-treat with bronchodilator before nebulization in reactive airway patients. Ophthalmic: instill 1–2 drops q6h. If a dose is missed This medication is administered by a veterinarian or veterinary staff in a clinical setting. Missed doses are managed by your veterinary team — contact your veterinarian to reschedule.

IV (NAC): anaphylactoid reactions (urticaria, bronchospasm, hypotension) — usually with rapid IV infusion; slow infusion reduces risk. Oral/nasogastric: nausea, vomiting. Nebulized: bronchospasm (especially in reactive airway disease — pretreat with bronchodilator).

For animals IV NAC: dilute before use; rapid infusion may cause anaphylactoid reactions — administer slowly. Nebulized: may cause bronchospasm in patients with reactive airway disease; pretreat with bronchodilator. Separate oral dosing from activated charcoal by 1–2 hrs. For people handling this medication Wash hands thoroughly with soap and water after handling. Avoid contact with eyes; if contact occurs, flush with water for 15 minutes and seek medical attention. Keep out of reach of children. If accidental ingestion occurs, contact Poison Control (1-800-222-1222). Nebulized form: avoid prolonged inhalation. Wash hands thoroughly with soap and water after handling.

Contact your veterinarian. Acetylcysteine overdose (antidote for acetaminophen toxicity) causes GI signs. High IV doses may cause anaphylactoid reactions. Managed by veterinary staff.