Please check your internet connection and try again.
# Acetylcysteine
## Overview
Acetylcysteine is a mucolytic agent used to thin mucus secretions and as an antidote for acetaminophen overdose.
## Primary Indications
* **Acetaminophen Overdose:** To prevent or reduce liver toxicity.
* **Mucolytic:** To thin mucus in respiratory conditions such as COPD, cystic fibrosis, and pneumonia.
## Adult Dosing
* **Acetaminophen Overdose:**
* **Loading Dose:** 150 mg/kg IV over 1 hour.
* **Second Infusion:** 50 mg/kg IV over the next 1 hour.
* **Third Infusion:** 100 mg/kg IV over the next 16 hours.
* The total duration is typically 20 hours. Higher doses may be considered in cases of massive overdose or elevated acetaminophen levels at 24 hours.
* **Mucolytic:**
* **Oral/Nebulized:** 200 mg to 400 mg inhaled every 4 to 12 hours.
* **Intravenous (less common for mucolytic):** Dosing varies; consult specific protocols.
## Pediatric Dosing
* **Acetaminophen Overdose:** Dosing is the same as adults based on weight (150 mg/kg, 50 mg/kg, 100 mg/kg over respective infusions).
* **Mucolytic:**
* **Nebulized:** 10% solution: 3-5 mL every 2-6 hours. 20% solution: 2-3 mL every 2-6 hours.
* **Oral:** 50-100 mg/kg/day divided into 2-4 doses, up to a maximum of 600 mg/day.
## Dose Adjustments
No specific dose adjustments are typically required for hepatic or renal impairment for the acetaminophen overdose protocol, as the goal is to replete glutathione stores.
## Contraindications
* Hypersensitivity to acetylcysteine.
## Adverse Effects
* **IV Administration (Acetaminophen Overdose):** Anaphylactoid reactions (rash, pruritus, bronchospasm, angioedema), flushing, tachycardia, hypotension. Nausea and vomiting are common.
* **Nebulized Administration:** Bronchospasm (especially in asthmatics), stomatitis, nausea, vomiting, rhinorrhea.
## Key Drug Interactions
* **Activated Charcoal:** May adsorb oral acetylcysteine, reducing its absorption. Administer oral acetylcysteine at least 1 hour after activated charcoal.
* **Nitroglycerin:** May potentiate hypotensive effects.
## Monitoring
* **Acetaminophen Overdose:**
* Serum acetaminophen levels (at presentation, 4 hours post-ingestion, and subsequent levels as indicated).
* Liver function tests (ALT, AST, bilirubin, INR) at baseline and then every 24 hours for at least 72 hours, or until normalization.
* Renal function and electrolytes.
* Clinical status, vital signs.
* **Mucolytic:**
* Respiratory status, sputum production, and clearance.
* Bronchospasm.
## Clinical Pearls
* The IV formulation for acetaminophen overdose is critical and has a distinct protocol. Oral administration is generally reserved for mucolytic therapy.
* Anaphylactoid reactions are common with IV acetylcysteine and can be managed by slowing the infusion rate or administering antihistamines. Bronchospasm can be treated with bronchodilators.
* For nebulized acetylcysteine, patients with asthma may experience bronchoconstriction. Co-administration of a bronchodilator is often recommended.
* The smell of acetylcysteine is often described as unpleasant ("rotten eggs").
***
*This information is intended for clinical use and does not replace a thorough review of the most current prescribing information, including full prescribing details, contraindications, warnings, and precautions. Always verify with the official drug monograph or relevant clinical guidelines.*
