Acetylcysteine is used as an adjunct therapy in conditions where thick, sticky mucus or mucopurulent secretions are present. These include chronic bronchopulmonary diseases such as chronic obstructive pulmonary disease (COPD), emphysema with bronchitis, chronic asthmatic bronchitis, and bronchiectasis. It is also indicated in acute respiratory conditions like asthma with mucus plugging, bronchitis, bronchopneumonia, tracheobronchitis, bronchiolitis, as well as pulmonary complications of cystic fibrosis and post-surgical lung complications.

Acetylcysteine is a mucolytic agent that decreases the thickness of mucus by breaking disulfide bonds in mucoproteins, making secretions easier to clear from the respiratory tract. It also exhibits antisecretory effects, helping to open airways and improve breathing. In addition, Acetylcysteine has antioxidant properties—it neutralizes harmful free radicals and acts as a precursor to glutathione, an important antioxidant in the body. Through this action, it helps protect respiratory tissues from oxidative damage and inflammation.

Effervescent tablet or Dispersible tablet: Adults and children above 6 years: One effervescent tablet of Acetylcysteine 600 mg a day (preferably in the evening). The duration of treatment should be 5 to 10 days in the acute treatment, whereas it may be continued in the chronic states for several months, according to the advice of the physician. Dissolve the tablets in a glass containing a small quantity of water, mixing it, if necessary, with a spoon. A palatable solution is thus obtained, which can be drunk directly from the glass.

Effervescent Granules:

• Adults and children above 6 years: 1 sachet Acetylcysteine 200 mg or 2 sachets Acetylcysteine 100 mg, 2-3 times a day.
• Children (2-6 years of age): 1 sachet Acetylcysteine 100 mg from 2 to 4 times a day, according to the age.

The duration of treatment should be 5 to 10 days in the acute treatment, whereas it may be continued in the chronic states for several months, according to the advice of the physician.

Dissolve the contents of the sachets in a glass containing a small quantity of water; mixing it, if necessary, with a spoon. A palatable solution is thus obtained, which can be drunk directly from the glass.

Nebuliser Solution: The 20% solution may be diluted to a lesser concentration with either Sodium Chloride for injection, Sodium Chloride for inhalation, sterile water for injection, or sterile water for inhalation.

• Adult: 5-10 ml of 10% or 20% solution by Nebuliser every 6-8 hr PRN.
• Children: 1-11 months: 1-2 ml of 20% or 2-4 ml of 10% solution by Nebuliser every 6-8 hr PRN.
• 12 months-11 years: 3-5 ml of 20% or 6-10 ml of 10% solution by Nebuliser every 6-8 hr PRN.
• Below 12 years: 5-10 ml of 10/20% solution by Nebuliser every 6-8 hr PRN.

** Diagnostic Bronchograms: 1-2 ml of 20% or 2-4 ml of 10% solution 2-3 times by Nebulisation or by instillation intratracheally prior to procedure.

** Nebulisation tent or croupette: This form of administration requires very large volumes of the solution, occasionally as much as 300 ml during a single treatment period. If a tent or croupette must be used, the recommended dose is the volume of acetylcysteine (using 20%) that will maintain a very heavy mist in the tent or croupette for the desired period. Administration for intermittent or continuous prolonged periods, including overnight, may be desirable.

** Direct Instillation: When used by direct instillation, 1-2 ml of a 20% solution may be given as often as every hour. When used for the routine nursing care of patients with tracheostomy, 1-2 ml of a 20% solution may be given every 1-4 hours by instillation into the tracheostomy.

The thiol group of Acetylcysteine may reduce the effectiveness of certain antibiotics such as ampicillin, tetracyclines, macrolides, cephalosporins, aminoglycosides, and amphotericin. When taken with amoxicillin, it may increase the antibiotic concentration in tissues; therefore, both drugs should be taken at least 2 hours apart. Acetylcysteine may also enhance the effects of nitroglycerin, including vasodilation and inhibition of platelet aggregation.

Acetylcysteine is contraindicated in patients with known hypersensitivity to the drug. Since it contains aspartame, it should not be used in individuals with phenylketonuria.

Although not everyone experiences side effects, Acetylcysteine may cause reactions in some individuals. Rarely, severe allergic reactions such as anaphylactic shock and serious skin reactions may occur. Oral use may sometimes lead to shortness of breath, stomach discomfort, or bronchospasm. Common side effects include headache, increased heart rate, mouth inflammation, itching, rash (urticaria), nausea, vomiting, abdominal pain, fever, low blood pressure, diarrhea, and ringing in the ears.

During pregnancy and breastfeeding, Acetylcysteine should be used only after consulting a physician or pharmacist.

Patients with bronchial asthma should be closely monitored, and treatment should be stopped immediately if bronchospasm occurs. Caution is required in patients with a history of peptic ulcer. Due to its sodium content, it should be used carefully in patients on a restricted sodium diet. A sulfur-like odor may be present, which is normal and does not indicate product deterioration. It is advisable not to mix this solution with other medications.

Overdose of Acetylcysteine may result in nausea, vomiting, and diarrhea.

Acetylcysteine belongs to the class of antidotes, cough expectorants, and mucolytic agents.

Store in a cool, dry place, protected from light.