Acetylcysteine
Rx
Therapeutic ClassMucolytic & Antidote
Common Dose600 mg / 200 mg IV
RouteOral, IV, Inhalation
PregnancyUse with caution
Indications ▼
Acetaminophen (Paracetamol) overdose
Chronic obstructive pulmonary disease (COPD) with thick mucus
Cystic fibrosis for mucus clearance
Bronchitis or respiratory infections with viscous secretions
Prevention of contrast-induced nephropathy (IV route)
Mechanism & Pharmacokinetics ▼
Mechanism: Breaks disulfide bonds in mucoproteins, reducing mucus viscosity. Acts as a glutathione precursor in liver, replenishing stores and detoxifying NAPQI in acetaminophen overdose.
Pharmacokinetics: Well absorbed orally (bioavailability ~10%), distributed widely in tissues. IV form bypasses first-pass metabolism. Metabolized in liver to cysteine and other metabolites. Half-life ~5.6 hours. Excreted in urine.
Dosage & Administration ▼
| Patient Group | Dose | Frequency / Duration |
|---|---|---|
| Adults (Oral) | 600 mg | Once or twice daily |
| IV for Paracetamol Overdose | 150 mg/kg in 200 mL D5W over 60 min, then 50 mg/kg in 500 mL over 4 hours, then 100 mg/kg in 1000 mL over 16 hours | Single course |
| Pediatric | 10–20 mg/kg per dose | 3–4 times daily |
Side Effects ▼
Nausea, vomiting
Diarrhea
Rash or pruritus
Fever, headache
Rare: Anaphylactoid reactions, bronchospasm (especially IV)
Contraindications ▼
Hypersensitivity to acetylcysteine or excipients
Severe asthma or bronchospasm (caution with inhalation)
Known hypersensitivity to IV excipients
Drug Interaction ▼
Activated charcoal may reduce oral absorption
May increase effectiveness of certain chemotherapy drugs
Concurrent use with nitrates or antihypertensives may potentiate hypotensive effect
Pregnancy & Lactation ▼
Use only if clearly needed
Generally considered safe during breastfeeding at recommended doses
Clinical / Research Summary ▼
Therapeutic Role: Acetylcysteine is a mucolytic agent used to reduce the viscosity of mucus in respiratory disorders such as chronic bronchitis, COPD, cystic fibrosis, and bronchiectasis. It is also used as an antidote for acetaminophen (paracetamol) overdose to prevent hepatotoxicity.
Mechanism-Based Evidence: Acetylcysteine acts by breaking disulfide bonds in mucoproteins, reducing mucus viscosity and facilitating expectoration. In acetaminophen toxicity, it replenishes hepatic glutathione stores and enhances detoxification of the toxic metabolite NAPQI.
Clinical Effectiveness: Clinical studies show improved airway clearance, reduced frequency of exacerbations in chronic respiratory conditions, and significantly decreased risk of liver damage when administered promptly after acetaminophen overdose.
Safety Profile: Generally well tolerated. Common side effects include nausea, vomiting, rash, and mild gastrointestinal discomfort. Rare adverse events include bronchospasm, hypotension (IV use), or hypersensitivity reactions.
Research Directions: Studies are ongoing to assess its role in preventing contrast-induced nephropathy, its antioxidant effects in respiratory diseases, and optimized dosing strategies for intravenous and inhaled formulations.
Patient Counseling Points ▼
Take oral form with a full glass of water
Avoid self-medication for overdose management
Report rash, breathing difficulty, or hypotension immediately
Store IV solutions per instructions, inspect for precipitation
Storage & Handling ▼
Store below 25°C, protect from light
Keep dry and out of reach of children
Do not freeze IV solutions
Brand Names (Bangladesh & Global) ▼
Medical Disclaimer: This clinical summary is for educational purposes only. Always consult a qualified healthcare provider before use.
.png)
