Generic Medicine Info
Indications and Dosage
Adult: As 10% or 20% solution: 1-2 mL as often as every hour.
Child: Same as adult dose.

Adult: As 10% solution: 6-10 mL 3-4 times daily, may increase to 2-20 mL 2-6 hourly as necessary. As 20% solution: 3-5 mL 3-4 times daily, may increase to 1-10 mL 2-6 hourly as necessary.
Child: Same as adult dose.

Paracetamol poisoning
Adult: Initially, 150 mg/kg (Max: 16.5 g) in 200 mL diluent over 1 hour, followed by 50 mg/kg (Max: 5.5 g) in 500 mL diluent over 4 hours, then 100 mg/kg (Max: 11 g) in 1 L diluent over the next 16 hours.
Child: <20 kg: Initially, 150 mg/kg in 3 mL/kg diluent over 1 hour, followed by 50 mg/kg in 7 mL/kg diluent over 4 hours, then 100 mg/kg in 14 mL/kg diluent over 16 hours; 20-39 kg: Initially, 150 mg/kg in 100 mL diluent over 1 hour, followed by 50 mg/kg in 250 mL diluent over 4 hours, then 100 mg/kg in 500 mL diluent over 16 hours; ≥40 kg: Same as adult dose.

Dry eye associated with abnormal mucus production
Adult: As 5% solution: Instill 1 or 2 drops into the conjunctival sac of the affected eye(s) 3 or 4 times daily.

Paracetamol poisoning
Adult: As effervescent tab: Initially, 140 mg/kg followed by 17 maintenance doses of 70 mg/kg given 4 hourly.
Child: Same as adult dose.

Adult: As powder for oral solution: 200 mg tid. Max: 600 mg daily. As effervescent tab: 600 mg once daily.
Child: As powder for oral solution: 2-6 years 100 mg 2-4 times daily; >6 years 200 mg 2-3 times daily. As effervescent tab: >6 years 600 mg once daily.
Powd For Oral Susp: Should be taken with food. Dissolve in water before taking.
Effervescent granules or tab: Dissolve in a glass of water before use. IV: Dilute for IV infusion with dextrose 5%, NaCl or sterile water for inj. Inhalation: 20% solution may be diluted with NaCl 0.9% inj or inhalation solution, or sterile water for inj or inhalation. For admin via gastric tube, use water as diluent. Oral solution: Dilute the 20% solution with an orange juice, cola or any diet soft drinks to a final concentration of 5%.
Incompatible with some metals (e.g. Fe, copper), rubber, oxygen and oxidising substances, some antimicrobials (e.g. amphotericin B, ampicillin Na, erythromycin lactobionate) and some tetracyclines.
Use of oral powder for solution and effervescent tab in children below 2 years of age.
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.
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).
Inhalation/Respiratory/IV/Parenteral/PO: B
Patient Counseling Information
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.
Oral: Symptoms: Nausea, vomiting, diarrhoea, anaphylactoid reactions. Management: Symptomatic and supportive treatment. May administer antihistamines and steroids for anaphylaxis.
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.
Lab Interference
May cause interference with colorimetric assay method for the determination of salicylates and with tests for ketones in urine.
Description: 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).
Chemical Structure

Chemical Structure Image

Source: National Center for Biotechnology Information. PubChem Database. Acetylcysteine, CID=12035, (accessed on Jan. 20, 2020)

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. Ophthalmic soln: Store below 25°C.
MIMS Class
Antidotes & Detoxifying Agents / Cough & Cold Preparations / Other Eye Preparations
ATC Classification
V03AB23 - acetylcysteine ; Belongs to the class of antidotes. Used to neutralize paracetamol overdose.
R05CB01 - acetylcysteine ; Belongs to the class of mucolytics. Used in the treatment of wet cough.
S01XA08 - acetylcysteine ; Belongs to the class of other ophthalmologicals.
Acetadote Injection, Solution (Cumberland Pharmaceuticals, Inc.). DailyMed. Source: U.S. National Library of Medicine. Accessed 31/07/2018.

Acetylcysteine Inhalant (American Regent, Inc.). DailyMed. Source: U.S. National Library of Medicine. Accessed 02/08/2018.

Acetylcysteine Injection, Solution (APP Pharmaceuticals, LLC). DailyMed. Source: U.S. National Library of Medicine. Accessed 17/11/2014.

Acetylcysteine Solution (Fresenius Kabi USA, LLC). DailyMed. Source: U.S. National Library of Medicine. Accessed 17/11/2014.

Anon. Acetylcysteine. AHFS Clinical Drug Information [online]. Bethesda, MD. American Society of Health-System Pharmacists, Inc. Accessed 17/11/2014.

Anon. Acetylcysteine. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. Accessed 17/11/2014.

Buckingham R (ed). Acetylcysteine. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. Accessed 17/11/2014.

Cetylev Tablet, Effervescent (Arbor Pharmaceuticals). DailyMed. Source: U.S. National Library of Medicine. Accessed 31/07/2018.

Joint Formulary Committee. Acetylcysteine. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. Accessed 31/07/2018.

Disclaimer: This information is independently developed by MIMS based on Acetylcysteine from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2022 MIMS. All rights reserved. Powered by
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