Please check your internet connection and try again.
# Acetylcysteine
## Overview
Acetylcysteine is a mucolytic agent used to break down and thin respiratory secretions. It is also the antidote for acetaminophen overdose.
## Primary Indications
* **Acetaminophen Overdose:** To prevent or reduce liver toxicity.
* **Mucolytic:** To thin thick mucus in conditions such as bronchitis, pneumonia, and COPD.
* **Adjunct in Bronchiolitis:** May be considered for infants with severe bronchiolitis and significant airway obstruction.
## Adult Dosing
* **Acetaminophen Overdose:**
* **Loading Dose:** 150 mg/kg IV infused over 1 hour.
* **Second Infusion:** 50 mg/kg IV infused over 4 hours.
* **Third Infusion:** 100 mg/kg IV infused over 16 hours.
* *Maximum dose depends on acetaminophen levels and hepatic function; local protocols should be followed.*
* **Mucolytic:**
* **Nebulized:** 1-10 mL of a 10-20% solution every 2-6 hours.
* **Oral:** 200 mg (or 600 mg for extended-release) 2-3 times daily.
## Pediatric Dosing
* **Acetaminophen Overdose:**
* Same as adult dosing (150 mg/kg IV over 1 hour, then 50 mg/kg IV over 4 hours, then 100 mg/kg IV over 16 hours).
* *Dosing should be based on actual or ideal body weight, whichever is less, for patients over 10 years.*
* **Mucolytic:**
* **Nebulized:** 1-10 mL of a 10-20% solution every 2-6 hours.
* **Oral:** 50-100 mg 2-4 times daily.
## Dose Adjustments
No specific dose adjustments are typically required for renal or hepatic impairment for the mucolytic indication. For acetaminophen overdose, dose may need adjustment based on acetaminophen levels, time of ingestion, and hepatic function.
## Contraindications
* Hypersensitivity to acetylcysteine.
* Active hemorrhage (especially with inhaled acetylcysteine).
## Adverse Effects
* **Nebulized:** Bronchospasm, stomatitis, nausea, vomiting, rhinorrhea.
* **IV (Acetaminophen Overdose):** Anaphylactoid reactions (rash, pruritus, flushing, urticaria, bronchospasm, angioedema, hypotension), nausea, vomiting. *These reactions are more common during the loading dose.*
* **Oral:** Nausea, vomiting, diarrhea, rash.
## Key Drug Interactions
* **Activated Charcoal:** May adsorb acetylcysteine, reducing its efficacy in acetaminophen overdose. Administer acetylcysteine at least 1 hour after activated charcoal if co-administration is unavoidable.
* **Nitroglycerin:** Concurrent use may potentiate hypotensive effects.
## Monitoring
* **Acetaminophen Overdose:**
* Acetaminophen levels at appropriate intervals.
* Liver function tests (ALT, AST, bilirubin, INR).
* Glucose.
* Signs and symptoms of anaphylactoid reaction.
* **Mucolytic:**
* Respiratory status and secretion clearance.
* Signs of bronchospasm.
## Clinical Pearls
* For IV administration in acetaminophen overdose, anaphylactoid reactions are common but often manageable with supportive care and slower infusion rates. Discontinuation is rarely necessary.
* Ensure adequate hydration when using acetylcysteine as a mucolytic.
* The smell of acetylcysteine is often described as sulfurous or like rotten eggs.
***
**Disclaimer:** This information is intended for healthcare professionals. Always consult the most current prescribing information and local protocols before administering any medication.
