Please check your internet connection and try again.
# Acetylcysteine
## Overview
Acetylcysteine (NAC) is a mucolytic agent and an antidote for acetaminophen overdose. It works by breaking disulfide bonds in mucus, reducing its viscosity, and replenishing intracellular glutathione stores.
## Primary Indications
* **Acetaminophen Overdose:** Treatment to prevent or reduce liver toxicity.
* **Mucolytic Agent:** To reduce the viscosity of pulmonary secretions in patients with conditions such as cystic fibrosis, chronic bronchitis, and emphysema.
## Adult Dosing
**Acetaminophen Overdose:**
* **Oral:** 140 mg/kg loading dose, followed by 70 mg/kg every 4 hours for 17 doses.
* **Intravenous (IV):** Protocol-dependent. A common regimen is a 150 mg/kg loading dose over 1 hour, followed by 50 mg/kg over the next 4 hours, and then 100 mg/kg over the subsequent 16 hours. Maximum doses vary by protocol.
* **Note:** Local protocols for IV acetylcysteine for acetaminophen overdose are highly variable and should be consulted.
**Mucolytic Agent:**
* **Inhaled:** 1 to 10 mL of a 10% or 20% solution every 2 to 6 hours as needed. Concentration and frequency are often guided by patient tolerance and response.
## Pediatric Dosing
**Acetaminophen Overdose:**
* Dosing is typically weight-based, similar to adults. Consult specific pediatric protocols for IV administration, which can vary significantly.
**Mucolytic Agent:**
* **Inhaled:** 10% solution: 1 to 2 mL every 2 to 6 hours. 20% solution: 1 mL every 2 to 6 hours. Neonates and infants may receive smaller volumes.
## Dose Adjustments
* **Renal Impairment:** No specific dose adjustment is typically recommended for inhaled or IV use in mild to moderate renal impairment. However, caution is advised, especially with IV administration, as data are limited.
* **Hepatic Impairment:** No specific dose adjustment is typically recommended, but caution and close monitoring are essential in severe hepatic impairment, especially during acetaminophen overdose treatment.
## Contraindications
* Known hypersensitivity to acetylcysteine.
* Caution in patients with asthma due to potential for bronchospasm with inhaled administration.
## Adverse Effects
* **Inhaled:** Bronchospasm, airway irritation, rhinorrhea, nausea, vomiting, stomatitis.
* **Intravenous:** Anaphylactoid reactions (rash, urticaria, pruritus, angioedema, bronchospasm, dyspnea), flushing, tachycardia, hypotension, fever.
## Key Drug Interactions
* **Activated Charcoal:** Can adsorb oral acetylcysteine, reducing its efficacy in acetaminophen overdose. Separate administration by at least 1 hour.
* **Nitroglycerin:** Potentiation of vasodilatory effects, leading to hypotension and headache.
## Monitoring
* **Acetaminophen Overdose:** Liver function tests (AST, ALT, bilirubin, INR), serum creatinine, glucose, and acetaminophen levels. Clinical assessment for signs of liver injury.
* **Mucolytic Use:** Pulmonary function, presence of bronchospasm, and patient tolerance.
## Clinical Pearls
* The odor of acetylcysteine is strong and sulfurous; this is normal.
* For IV administration in acetaminophen overdose, prompt initiation is critical for optimal liver protection.
* Dilute IV acetylcysteine for infusion as per institutional protocol to reduce the risk of adverse reactions.
* For inhaled use, consider bronchodilator pre-treatment if bronchospasm is a concern.
***
**Disclaimer:** This information is intended for healthcare professionals. Always consult the most current prescribing information and institutional protocols before administering any medication.
