Acetyl%2525252525252525252525252525252525252525252525252525252525252525252520cysteine

# Acetylcysteine ## Overview Acetylcysteine is a mucolytic agent and an antidote for acetaminophen overdose. It works by breaking disulfide bonds in mucoproteins, reducing mucus viscosity. As an antidote, it replenishes glutathione stores and conjugates with the toxic metabolite of acetaminophen. ## Primary Indications * **Acetaminophen Overdose:** Treatment of acetaminophen or N-acetyl-cysteine (NAC) overdose to prevent hepatotoxicity. * **Mucolytic Agent:** To thin mucus secretions in conditions such as chronic bronchitis, emphysema, and cystic fibrosis. ## Adult Dosing **Acetaminophen Overdose:** * **Oral:** An initial loading dose of 140 mg/kg followed by 70 mg/kg every 4 hours for a total of 17 doses. * **Intravenous (IV):** Dosing regimens vary by protocol. A common regimen includes a loading dose of 150 mg/kg IV over 1 hour, followed by 12.5 mg/kg/hour IV for 4 hours, then 6.25 mg/kg/hour IV for 16 hours. Check local protocols for precise IV dosing and infusion rates. Maximum doses are protocol-dependent. **Mucolytic Agent:** * **Oral:** 200 mg to 400 mg two to three times daily. * **Inhaled:** 1 to 10 mL of a 10% or 20% solution, or 3 to 5 mL of a 10% solution, administered by nebulization every 2 to 6 hours. Some protocols may recommend higher doses or more frequent administration. ## Pediatric Dosing **Acetaminophen Overdose:** * **Oral:** Same as adult: 140 mg/kg loading dose, then 70 mg/kg every 4 hours for 17 doses. * **Intravenous (IV):** Generally follows adult IV protocols, but may require different concentrations or slower infusion rates in neonates and infants. Check local protocols. **Mucolytic Agent:** * **Inhaled:** 1 to 10 mL of a 10% or 20% solution, or 3 to 5 mL of a 10% solution, administered by nebulization every 2 to 6 hours. Dosing is often weight-based for younger children, typically 200 mg once or twice daily via nebulizer. ## Dose Adjustments No specific dose adjustments are typically required for hepatic or renal impairment, though caution is advised in severe cases. ## Contraindications Hypersensitivity to acetylcysteine. ## Adverse Effects * **Most Common (Oral):** Nausea, vomiting, rhinorrhea, drowsiness. * **Most Common (Inhaled):** Bronchospasm (especially in asthmatics), stomatitis, rash. * **Most Common (IV):** Anaphylactoid reactions (hypotension, bronchospasm, rash, angioedema), urticaria, pruritus. Rapid infusions can increase the risk of anaphylactoid reactions. ## Key Drug Interactions * **Activated Charcoal:** May adsorb oral acetylcysteine, reducing its absorption. Separate administration by at least 2 hours. * **Nitroglycerin:** May potentiate the hypotensive effect of nitroglycerin. Monitor blood pressure. ## Monitoring * **Acetaminophen Overdose:** Serum acetaminophen levels, liver function tests (AST, ALT, bilirubin, INR), blood glucose, serum electrolytes, and renal function. * **Mucolytic Agent:** Respiratory status, sputum characteristics, and signs of bronchospasm. ## Clinical Pearls * For IV administration in acetaminophen overdose, using protocols is crucial. Rapid IV infusions can increase the risk of severe anaphylactoid reactions. Pre-treatment with antihistamines may be considered but does not eliminate risk. * Oral acetylcysteine can have an unpleasant sulfurous odor. Flavoring agents or dilution may improve palatability. * Inhaled acetylcysteine can act as a bronchoconstrictor, particularly in patients with asthma. Co-administration of a bronchodilator is often recommended. *** **Disclaimer:** This information is for educational purposes only and does not substitute for professional medical advice. Always verify current prescribing information and consult with a qualified healthcare provider for any health concerns or before making any treatment decisions.