Mucolytics act directly on mucus, breaking down sticky, thick se-cretions so that they’re more easily eliminated.
Acetylcysteine is the only mucolytic used clinically in the UnitedStates for the patient with abnormal or thick mucus.
Inhaled acetylcysteine is absorbed from the pulmonary epitheli-um. When taken orally, the drug is absorbed from the GI tract.
Acetylcysteine is metabolized in the liver; its excretion is un-known.
Acetylcysteine decreases the thickness of respiratory tract secre-tions by altering the molecular composition of mucus. It also irri-tates the mucosa to stimulate clearance and restores glutathione, a substance that plays an important role in oxidation-reduction processes.
Glutathione’s enzymatic action in the liver reduces acetaminophen toxicity from overdose.
Mucolytics are used with other therapies to treat the patient with abnormal or thick mucus secretions, such as the patient with:
§ atelectasis caused by mucus obstruction, as may occur in pneu-monia, bronchiectasis, or chronic bronchitis
§ pulmonary complications related to cystic fibrosis.
Mucolytics may also be used to prepare the patient for bronchog-raphy and other bronchial studies.
Acetylcysteine is the antidote for acetaminophen overdose. How-ever, it doesn’t fully protect against liver damage caused by aceta-minophen toxicity.
Activated charcoal decreases acetylcysteine’s effectiveness. When using acetylcysteine to treat an acetaminophen overdose, remove activated charcoal from the stomach before administering. (See Adverse reactions to acetylcysteine.)