Acetylcysteine
Indications
Acetylcysteine is used for:
Tuberculosis, Chronic emphysema, Paracetamol poisoning, Bronchiectasis, Pneumonia, Atelectasis, Cystic fibrosis, Tracheostomy care, during anaesthesia
Adult Dose
Oral
As a mucolytic
Adult: As effervescent granules or tablets: 200 mg tid.
Paracetamol poisoning
Adult: After gastric lavage or induction of emesis with ipecac syrup, admin loading dose of 140 mg/kg, followed by maintenance doses of 70 mg/kg every 4 hr for a total of 17 doses. 1st maintenance dose to be given 4 hr after the loading dose. Repeat dose if the patient vomits within 1 hr of admin. Continue therapy until paracetamol levels are not detectable and there is no evidence of hepatotoxicity.
Inhalation
As a mucolytic
Adult: 3-5 ml of a 20% solution or 6-10 ml of a 10% solution 3-4 times daily by nebulising through a face mask, mouth piece or tracheostomy. May increase to 1-10 ml of a 20% solution or 2-20 ml of a 10% solution every 2-6 hr if needed.
Endotracheal
As a mucolytic
Adult: Instill 1-2 ml of a 10-20% solution as often as every hrly.
Child Dose
Oral
As a mucolytic
Child: As effervescent granules or tablets: 2-7 yr: 200 mg bid; <2 yr: 200 mg daily.
Paracetamol poisoning
Child: After gastric lavage or induction of emesis with ipecac syrup, admin loading dose of 140 mg/kg, followed by maintenance doses of 70 mg/kg every 4 hr for a total of 17 doses. 1st maintenance dose to be given 4 hr after the loading dose. Repeat dose if the patient vomits within 1 hr of admin. Continue therapy until paracetamol levels are not detectable and there is no evidence of hepatotoxicity.
Inhalation
As a mucolytic
Child: 3-5 ml of a 20% solution or 6-10 ml of a 10% solution 3-4 times daily by nebulising through a face mask, mouth piece or tracheostomy. May increase to 1-10 ml of a 20% solution or 2-20 ml of a 10% solution every 2-6 hr if needed.
Endotracheal
As a mucolytic
Child: Instill 1-2 ml of a 10-20% solution as often as every hrly.
Renal Dose
Administration
Contra Indications
Acetylcysteine is contraindicated in those patients who are sensitive to it.
Precautions
Asthmatic patients, history of bronchospasm, peptic ulceration. Pregnancy, lactation.
Lactation: Unknown whether agent is excreted in milk; use with caution.
Pregnancy-Lactation
Pregnancy category: B
Lactation: Unknown whether agent is excreted in milk; use with caution
Interactions
Drug stability and safety of acetylcysteine when mixed with other drugs in a nebulizer have not been established.
Adverse Effects
Side effects of Acetylcysteine :
Flushing, fever, stomatitis, nausea, vomiting, rhinorrhoea, bronchospasm, anaphylactoid reactions, rashes. Rarely, blurred vision, bradycardia, syncope, thrombocytopenia, convulsions.
Potentially Fatal: Rarely, respiratory or cardiac arrest.
Mechanism of Action
Acetylcysteine may decrease the viscosity of secretions by splitting of disulphide bonds in mucoproteins. It also promotes the detoxification of an intermediate paracetamol metabolite which is used in the management of paracetamol overdosage.