Acetyl Cysteine
Synonym :
N-Acetyl Cysteine
Mechanism :
Acetylcysteine is the N-acetyl derivative of the naturally-occurring amino acid, cysteine. The compound is a white crystalline powder with the molecular formula C5H9NO3S5 a molecular weight of 163.2, and chemical name of N-acetyl-L-cysteine.
Acetylcysteine has mucolytic function which is related to the sulfhydryl group in the molecule. This group "opens" disulfide linkages in mucus thus lowering the viscosity.
Indication :
- Acetaminophen toxicity
- Post liver transplant
- Acute liver failure
- Adjunctive therapy in patients with abnormal or viscid mucous secretions in bronchopulmonary diseases, pulmonary complications of surgery, and cystic fibrosis.
- Meconium ileus
Contraindications :
In patients with a prior history of hypersensitivity to any of the ingredients. Also, in asthmatics and patients with history of bronchospasm.
Dosing :
Only the 72-hour oral and 21-hour IV regimens are FDA approved.
Paracetamol overdose: (ideally within 8-10 hours following ingestion)
IV: Loading dose of 150 mg/kg IV in D5W infused over 1 hour, followed by 50 mg/kg in D5W infused over 4 hours and then 100 mg/kg IV in D5W infused over 16 hours.
Oral: 75 mg/kg orally every 4 hours for next 2-3 days.
Acute liver failure:
IV:
100 mg/kg/d IV infusion upto 72 hours.
Mucolytic:
Administer aerosolized bronchodilator 10-15 minutes prior to acetylcysteine nebulization.
1-11 months: 1-2 mL of 20% or 2-4 mL of 10% solution by nebulizer every 6-8 hours as when required.
12 months-11 years: 3-5 mL of 20% or 6-10 mL of 10% solution by nebulizer every 6-8 hours.
>11 years: 6-10 ml of 10% solution or 3-5 ml of 20% solution by nebulizer every 6-8 hours.
Adverse Effect :
Anaphylaxis and hypersensitivity reactions causing flushing, urticaria, angioedema, nausea, vomiting, tachycardia, hypotension, bronchospasm, chest tightness, disagreeable odour, drowsiness, fever, hemoptysis, increased volume of bronchial secretions.
Interaction :
There are no significant drug interactions with acetylcysteine however caution must be taken while administering it with:
Auranofin, activated charcoal and Gold sodium thiomalate: May decrease the efficacy of acetylcysteine.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
| 20-50 | Dose as in normal renal function |
| 10-20 | Dose as in normal renal function |
| <10 | Dose as in normal renal function. |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Likely to be Dialysed. Dose as in normal renal function |
| HD | Dialysed. Dose as in normal renal function |
| HDF/High flux | Dialysed. Dose as in normal renal function |
| CAV/VVHD | Likely to be Dialysed. Dose as in normal renal function |
Hepatic Dose :
Although there is a 3-fold increase in acetylcysteine plasma concentrations in patients with cirrhosis, no dosage adjustments are recommended.