Acetyl%2525252525252525252525252525252525252525252525252525252525252525252525252525252525252525252520cysteine

# Acetylcysteine ## Overview Acetylcysteine is a mucolytic agent that breaks disulfide bonds in mucoproteins, reducing mucus viscosity. It also serves as an antidote for acetaminophen overdose by replenishing glutathione stores. ## Primary Indications * **Acetaminophen overdose:** Antidote. * **Mucolytic:** To thin and loosen mucus in conditions such as chronic bronchitis, emphysema, cystic fibrosis, and pneumonia. ## Adult Dosing * **Acetaminophen overdose:** * **Oral:** Loading dose of 140 mg/kg, followed by 70 mg/kg every 4 hours for 17 doses (total 72 hours). * **Intravenous (IV):** Protocols vary; common regimens involve an initial loading dose (e.g., 150 mg/kg over 1 hour), followed by a continuous infusion (e.g., 12.5-15 mg/kg/hour for up to 72 hours). *Consult local protocol or specific institutional guidelines as IV dosing and formulations differ significantly.* * **Mucolytic:** * **Nebulized:** 20% solution: 3-5 mL every 3-12 hours. 10% solution: 6-10 mL every 3-12 hours. * **Oral:** Typically 200 mg twice daily to three times daily. ## Pediatric Dosing * **Acetaminophen overdose:** * **Oral:** Similar to adults: 140 mg/kg loading dose, followed by 70 mg/kg every 4 hours for 17 doses. * **Intravenous (IV):** Protocols are weight-based and vary by age and hospital. *Always consult local protocol or specific institutional guidelines for pediatric IV dosing.* * **Mucolytic:** * **Nebulized:** Generally the same as adults, though lower volumes may be used for smaller children. Dosing depends on protocol. * **Oral:** Dosing typically ranges from 50-200 mg twice to three times daily, depending on age and indication. ## Dose Adjustments No dose adjustments are typically required for renal or hepatic impairment for the mucolytic indication. For acetaminophen overdose, dose adjustments are not usually necessary unless specific patient factors warrant it (e.g., vomiting). ## Contraindications Hypersensitivity to acetylcysteine or any component of the formulation. Bronchospasm (with nebulized use, though pretreatment with bronchodilators may be considered). ## Adverse Effects * **Nebulized:** Bronchospasm, stomatitis, nausea, vomiting, rhinorrhea. * **Oral:** Nausea, vomiting, diarrhea, abdominal pain, rash. * **Intravenous (Acetaminophen Overdose):** Anaphylactoid reactions (hypotension, bronchospasm, rash, angioedema), fever, rash. ## Key Drug Interactions * **Activated Charcoal:** May bind to oral acetylcysteine, reducing its absorption. If co-administered for overdose, separate doses or consider IV acetylcysteine. * **Nitroglycerin:** Potential for additive hypotension. ## Monitoring * **Acetaminophen Overdose:** Monitor acetaminophen and its metabolite (APAP-glu, APAP-sulf) and 4-hour post-ingestion acetaminophen levels. Monitor liver function tests (LFTs), INR, glucose, and renal function. Observe for adverse reactions to acetylcysteine. * **Mucolytic:** Assess sputum volume and consistency, patient's ability to clear secretions, and respiratory status. Monitor for bronchospasm. ## Clinical Pearls * The characteristic "rotten egg" smell of acetylcysteine is normal. * For nebulized use, consider administering a bronchodilator first if the patient has reactive airway disease to minimize bronchospasm. * Oral formulations may be flavored to improve palatability. Vomiting is common with oral dosing, and patients may require antiemetics. * Intravenous administration for acetaminophen overdose is associated with anaphylactoid reactions; continuous monitoring is essential. Protocols vary significantly by institution. *** **Disclaimer:** This information is intended for healthcare professionals and is not a substitute for professional medical advice. Always consult the current prescribing information and relevant guidelines before administering any medication.