Oral
As a mucolytic
Oral
Paracetamol poisoning
Inhalation
As a mucolytic
Endotracheal
As a mucolytic
Intravenous
Paracetamol poisoning
Ophthalmic
Dosage/Direction for Use
Oral As a mucolytic Oral Paracetamol poisoning Inhalation As a mucolytic Endotracheal As a mucolytic Intravenous Paracetamol poisoning Ophthalmic |
Contraindications
Use of oral powder for solution and effervescent tab in children below 2 years of age.
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Special Precautions
Patient with known or history of atopy and asthma, history of bronchospasm, history of. peptic ulcer disease, esophageal varices. Children. Pregnancy and lactation. Patient Counselling Ophthalmic: This drug may cause blurred vision, if affected, do not drive or operate machinery. Should not be used in patients who wear soft contact lenses. Monitoring Parameters Paracetamol poisoning: Monitor serum paracetamol levels, AST, ALT, bilirubin, prothrombin time, INR, serum creatinine, BUN, serum glucose, Hb, haematocrit and electrolytes.
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Adverse Reactions
Significant: Hypersensitivity reactions (e.g. urticaria, rash, hypotension, wheezing, dyspnoea); fluid overload resulting in hyponatraemia and seizures, decreased prothrombin time, acute flushing, skin erythema (IV); risk of upper gastrointestinal haemorrhage (oral); haemoptysis, rhinorrhoea, stomatitis (inhalation).
Cardiac disorders: Cardiac arrest.
Eye disorders: Ophthalmic: Itching, redness, eye irritation, blurred vision.
Gastrointestinal disorders: Nausea, vomiting.
General disorders and administration site conditions: Fever, sweating.
Investigations: Liver function disturbances.
Metabolism and nutrition disorders: Acidosis.
Musculoskeletal and connective tissue disorders: Arthralgia.
Nervous system disorders: Convulsion.
Respiratory, thoracic and mediastinal disorders: Respiratory arrest.
Vascular disorders: Hypo/hypertension, syncope.
Potentially Fatal: Serious hypersensitivity reactions (e.g. bronchospasm, angioedema), fluid overload resulting in hyponatraemia and seizures (IV). |
Overdosage
Oral: Symptoms: Nausea, vomiting, diarrhoea, anaphylactoid reactions. Management: Symptomatic and supportive treatment. May administer antihistamines and steroids for anaphylaxis.
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Drug Interactions
Build-up of bronchial secretions due to reduced cough reflex with antitussive drugs. Reduced effect with activated charcoal. May enhance the vasodilatory effects of nitroglycerin. May reduce the pharmacological effects of antibiotics.
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Lab Interference
May cause interference with colorimetric assay method for the determination of salicylates and with tests for ketones in urine.
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Action
Acetylcysteine exerts mucolytic action through its free sulfhydryl group which opens up the disulfide bonds in the mucoproteins, thus lowering mucous viscosity. It is a precursor of glutathione which serves as a substrate for the synthesis of glutathione in the body. In paracetamol toxicity, acetylcysteine acts as a hepatoprotective agent by restoring hepatic glutathione, serving as a glutathione substitute, and enhancing the nontoxic sulfate conjugation of paracetamol.
Synonyms: N-acetylcysteine.
Onset: Inhalation: 5-10 minutes. Duration: Inhalation: >1 hour. Absorption: Rapidly absorbed from the gastrointestinal tract. Bioavailability: 4-10% (oral). Time to peak plasma concentration: 1-2 hours (oral solution), 1-3.5 hours (effervescent tablet). Distribution: Crosses the placenta and detected in cord blood. Volume of distribution: 0.47 L/kg. Plasma protein binding: 66-87%. Metabolism: Metabolised in the liver and metabolism in the gut wall to form cysteine and disulfides; cysteine is further metabolised to form glutathione and other metabolites. Undergoes extensive first-pass metabolism. Excretion: Via urine (13-38%). Elimination half-life: 6.25 hours for total acetylcysteine (oral); 2-6 hours (IV). |
Storage
Endotracheal: Effervescent tab/unopened soln: Store 20-25°C. Oral soln/Soln for inhalation: Following exposure to air, store between 2-8°C and use within 96 hours. Inhalation: Oral soln/Soln for inhalation: Following exposure to air, store between 2-8°C and use within 96 hours. Ophthalmic: Ophthalmic soln: Store below 25°C. Oral: Effervescent tab/unopened soln: Store 20-25°C. Oral soln/Soln for inhalation: Following exposure to air, store between 2-8°C and use within 96 hours.
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ATC Classification
V03AB23 - acetylcysteine ; Belongs to the class of antidotes. Used to neutralize paracetamol overdose.
S01XA08 - acetylcysteine ; Belongs to the class of other ophthalmologicals. R05CB01 - acetylcysteine ; Belongs to the class of mucolytics. Used in the treatment of wet cough. |