Please check your internet connection and try again.
# Acetylcysteine
## Overview
Acetylcysteine is a mucolytic agent that breaks disulfide bonds in mucoproteins, decreasing the viscosity of mucus. It is also an antidote for acetaminophen overdose.
## Primary Indications
* **Acetaminophen Overdose:** Treatment of acetaminophen toxicity.
* **Mucolytic Agent:** To thin respiratory secretions in patients with conditions such as chronic bronchitis, emphysema, and cystic fibrosis.
## Adult Dosing
* **Acetaminophen Overdose:**
* **Loading Dose:** 150 mg/kg intravenously (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 patient weight and duration of treatment.
* Alternative oral regimens exist but are less preferred due to risk of vomiting and potential for decreased absorption.
* **Mucolytic Agent:**
* **Inhalation:** 1 to 10 mL of a 20% solution or 2 to 20 mL of a 10% solution via nebulizer every 2 to 6 hours.
* **Direct Instillation:** 1 to 2 mL of a 10% to 20% solution into the tracheostomy tube every 1 to 4 hours.
## Pediatric Dosing
* **Acetaminophen Overdose:** Dosing is the same as adult dosing (150 mg/kg IV over 1 hour, followed by 50 mg/kg IV over 4 hours, followed by 100 mg/kg IV over 16 hours).
* **Mucolytic Agent:**
* **Inhalation:** 1 to 2 mL of a 10% solution or 0.5 to 1 mL of a 20% solution via nebulizer every 2 to 6 hours.
## Dose Adjustments
No specific dose adjustments are routinely recommended for renal or hepatic impairment for either indication, but caution is advised.
## Contraindications
* Known hypersensitivity to acetylcysteine.
* Active hemorrhage (especially with oral administration for mucolytic effects).
## Adverse Effects
* **IV Administration:** Anaphylactoid reactions (bronchospasm, rash, pruritus, angioedema, hypotension), urticaria, angioedema, rash, fever, headache, nausea, vomiting.
* **Inhalation:** Bronchospasm, rhinorrhea, nausea, vomiting, stomatitis.
* **Oral Administration:** Nausea, vomiting, stomatitis.
## Key Drug Interactions
* **Activated Charcoal:** May bind acetylcysteine and reduce its systemic absorption when used for acetaminophen overdose. Separate administration by at least 1 hour.
* **Nitroglycerin:** Potentiated vasodilator effect. Monitor blood pressure.
## Monitoring
* **Acetaminophen Overdose:**
* Serum acetaminophen levels.
* Liver function tests (AST, ALT, bilirubin, PT/INR).
* Renal function (creatinine, BUN).
* Blood glucose.
* Electrolytes.
* Vital signs, especially for signs of anaphylactoid reaction.
* **Mucolytic Agent:**
* Respiratory status (breath sounds, oxygen saturation, work of breathing).
* For signs of bronchospasm.
## Clinical Pearls
* The IV preparation for acetaminophen overdose is a different concentration and formulation than the inhalation solution. Do not interchange.
* Anaphylactoid reactions are common with IV acetylcysteine and are often dose-related but not necessarily indicative of true IgE-mediated allergy. Slowing the infusion rate can often manage these reactions.
* For inhalation use, diluting the 20% solution to 10% may be preferred to reduce irritation.
* Hydration is important to help mobilize secretions.
**Disclaimer:** This information is intended for healthcare professionals. Always consult the current prescribing information and institutional protocols for definitive guidance, as drug information can change.
