Please check your internet connection and try again.
# Acetylcysteine
## Overview
Acetylcysteine is a mucolytic agent that breaks disulfide bonds in mucoproteins, reducing the viscosity of mucus. It is also an antidote for acetaminophen overdose by replenishing hepatic glutathione stores.
## Primary Indications
* **Acetaminophen Overdose:** To prevent or reduce liver damage.
* **Mucolytic:** To thin mucus in respiratory conditions such as cystic fibrosis, chronic obstructive pulmonary disease (COPD), and bronchitis.
## Adult Dosing
### Acetaminophen Overdose
* **IV:** Typically a 3-bag (21-hour) protocol.
* **Loading Dose:** 150 mg/kg infused over 60 minutes.
* **Second Infusion:** 50 mg/kg infused over the next 60 minutes.
* **Third Infusion:** 100 mg/kg infused over the final 12 hours.
* **Maximum Dose:** Based on total body weight and duration.
* **PO:** Oral protocol varies but generally involves larger initial doses followed by subsequent doses. *Intravenous is preferred due to better absorption and lower risk of anaphylactoid reactions.*
### Mucolytic
* **Inhalation:** 1-10 mL of a 20% solution or 2-20 mL of a 10% solution, nebulized every 4-12 hours.
* **Direct Instillation:** 1-2 mL of a 10-20% solution instilled into endotracheal tube every 1-4 hours.
## Pediatric Dosing
### Acetaminophen Overdose
* **IV:** Dosing is weight-based and follows the same 3-bag protocol as adults:
* **Loading Dose:** 150 mg/kg infused over 60 minutes.
* **Second Infusion:** 50 mg/kg infused over the next 60 minutes.
* **Third Infusion:** 100 mg/kg infused over the final 12 hours.
* **Maximum Dose:** Based on total body weight and duration.
* **PO:** Oral protocol varies and is often weight-based. *Intravenous is preferred.*
### Mucolytic
* **Inhalation:**
* **1 month to 18 years:** 1-10 mL of a 20% solution or 2-20 mL of a 10% solution, nebulized every 4-12 hours.
## Dose Adjustments
No specific dose adjustments are typically required for hepatic or renal impairment. However, monitoring is crucial in these populations.
## Contraindications
* Hypersensitivity to acetylcysteine or any component of the formulation.
* Active hemorrhage (for inhalation use).
## Adverse Effects
* **Common (Inhalation):** Bronchospasm, stomatitis, nausea, vomiting, rhinorrhea.
* **Common (IV for Overdose):** Anaphylactoid reactions (rash, urticaria, pruritus, flushing, tachycardia, hypotension, dyspnea), angioedema. These are generally managed by slowing infusion rate or administering antihistamines.
## Key Drug Interactions
* **Activated Charcoal:** Can bind to oral acetylcysteine, reducing its absorption. Administer oral acetylcysteine at least 1 hour after activated charcoal.
* **Nitroglycerin:** May potentiate nitroglycerin's vasodilatory effects, leading to hypotension and headache.
## Monitoring
* **Acetaminophen Overdose:**
* Serum acetaminophen levels.
* Liver function tests (AST, ALT, bilirubin, INR).
* Renal function.
* Glucose levels.
* Clinical signs of liver injury.
* **Mucolytic:**
* Pulmonary status.
* Bronchospasm.
## Clinical Pearls
* For IV administration in acetaminophen overdose, it is crucial to follow the established protocol precisely.
* Anaphylactoid reactions are common with IV acetylcysteine but are usually not a reason to discontinue therapy. Manage symptomatically.
* Ensure adequate hydration when using acetylcysteine for mucolytic effects.
* If a patient experiences bronchospasm with nebulized acetylcysteine, consider co-administration with a bronchodilator.
***
**Disclaimer:** This information is intended for healthcare professionals and does not replace individual clinical judgment. Always consult the most current prescribing information and relevant guidelines before initiating or modifying therapy.
