Learning Outcomes
By the end of this section, you should be able to:
- 24.3.1 Identify the characteristics of expectorant and mucolytic drugs used to treat respiratory disorders.
- 24.3.2 Explain the indications, actions, adverse reactions, and interactions of expectorant and mucolytic drugs used to treat respiratory disorders.
- 24.3.3 Describe nursing implications of expectorant and mucolytic drugs used to treat respiratory disorders.
- 24.3.4 Explain the client education related to expectorant and mucolytic drugs used to treat respiratory disorders.
Expectorants
Expectorants are a class of drugs that help to clear mucus from the airways when coughing. Expectorants can be stand-alone drugs or can be a part of combination cold and flu preparations. Expectorants do not suppress the cough like antitussives do, so they should only be used with productive coughs when it is necessary to loosen and clear mucus. Expectorants work by lubricating the airways, stimulating the cough reflex, and decreasing mucus viscosity so that it is easier to expel (Cleveland Clinic, 2021).
Guaifenesin
Guaifenesin is a common expectorant and is available over the counter without a prescription. It increases production of respiratory tract fluids to help liquefy mucus and make it easier to expel.
Adverse Effects and Contraindications
Guaifenesin does not cause many adverse effects, but dizziness, headache, nausea, and vomiting may occur.
Table 24.13 is a drug prototype table for expectorants featuring guaifenesin. It lists drug class, mechanism of action, adult and pediatric dosage, indications, therapeutic effects, drug and food interactions, adverse effects, and contraindications.
| Drug Class Expectorant Mechanism of Action Increases production of respiratory tract fluids to liquefy mucus |
Drug Dosage 200 mg orally every 4 hours. Extended-release tablets: 600–1200 mg orally every 12 hours. Maximum dose: 2400 mg daily. |
| Indications Productive coughs where there is a need to clear the airway of mucus Therapeutic Effects Thinner mucus that is easy to cough up and expel |
Drug Interactions Cimetidine Naltrexone Food Interactions No significant interactions |
| Adverse Effects Headache Dizziness Nausea Vomiting Urticaria |
Contraindications Hypersensitivity Children under age 12 (extended-release preparations) Caution: Pregnancy |
Mucolytics
Mucolytics also help clients to clear mucus from the airway. They differ from expectorants in that they are used to help high-risk respiratory clients cough up thick, tenacious mucus. Mucolytics directly break down the structure of mucus by breaking its protein bonds, helping to reduce the thickness and stickiness of mucus. Clients with tracheostomies often benefit from mucolytics. Mucolytics are also sometimes used to clear the airway in preparation for a bronchoscopy.
Acetylcysteine
Acetylcysteine is used to help clients clear thick, tenacious mucus from the airways. It is often used in clients with pneumonia, bronchitis, cystic fibrosis, and emphysema. It can also be used prior to bronchial studies, such as bronchoscopy, to help clear the airway and is also used as routine tracheostomy care. To manage respiratory symptoms, the medication is inhaled. Acetylcysteine is also administered orally or intravenously as the antidote for acetaminophen toxicity.
Side effects include tachycardia, nausea, and vomiting. Acetylcysteine is contraindicated in clients with hypersensitivity to it or those with peptic ulcer disease.
Dornase Alfa
Dornase alfa is another mucolytic used most often to lower the number of lung infections and help lung function in cystic fibrosis. Dornase alfa acts like an enzyme naturally found in the lungs to help thin out thick, sticky mucus. Removing mucus in these clients helps to reduce the number of infections that they may have by reducing the potential breeding ground for bacteria.
Dornase alfa can cause voice changes, hoarseness, and sore throat. It is contraindicated in those with hypersensitivity to the drug or to Chinese hamster ovary cell products used in the pharmaceutical industry.
Table 24.14 lists common mucolytics and typical routes and dosing for adult clients.
| Drug | Routes and Dosage Ranges |
|---|---|
| Acetylcysteine (Mucomyst) |
For removal of secretions in clients with cystic fibrosis, bronchitis, and other respiratory disorders: 1–2 mL of 10%–20% solution inhalant instilled into trachea as often as every hour. Prior to diagnostic studies: 2–3 administrations of 1–2 mL of 20% solution inhalant or 2–4 mL of 10% solution inhalant prior to procedure. For routine tracheostomy care: 1–2 mL of 10%–20% solution inhalant by direct instillation into tracheostomy every 1–4 hours. |
| Dornase alfa (Pulmozyme) |
2.5 mg of inhalant in nebulizer once daily. |
Adverse Effects and Contraindications
Mucolytics can cause tachycardia, nausea, and vomiting. Some clients may experience voice changes, hoarseness, and sore throat. Clients with hypersensitivity to mucolytics and those with peptic ulcer disease should avoid these drugs.
Table 24.15 is a drug prototype table for mucolytics featuring acetylcysteine. It lists drug class, mechanism of action, adult dosage, indications, therapeutic effects, drug and food interactions, adverse effects, and contraindications.
| Drug Class Mucolytic Mechanism of Action Reduces viscosity of pulmonary secretions |
Drug Dosage For removal of secretions in clients with cystic fibrosis, bronchitis, and other respiratory disorders: 1–2 mL of 10%–20% solution inhalant instilled into trachea as often as every hour. Prior to diagnostic studies: 2–3 administrations of 1–2 mL of 20% solution inhalant or 2–4 mL of 10% solution inhalant prior to procedure. Routine tracheostomy care: 1–2 mL of 10%–20% solution inhalant by direct instillation into tracheostomy every 1–4 hours. |
| Indications Adjunctive therapy for pneumonia, bronchitis, and cystic fibrosis Therapeutic Effects Thins pulmonary secretions and allows for easier clearance |
Drug Interactions Activated charcoal Food Interactions No significant interactions |
| Adverse Effects Fever Tachycardia Nausea Vomiting Pharyngitis Bronchospasm Dyspnea |
Contraindications Hypersensitivity Peptic ulcer disease Caution: Older adults with debilitation or severe respiratory insufficiency Asthma (IV form) |
Link to Learning
Respiratory Therapy Zone
This video from Respiratory Therapy Zone discusses the mucolytic agent acetylcysteine.
Safety Alert
Mucolytics
Because acetylcysteine commonly causes vomiting, it should be strictly avoided in clients with peptic ulcer disease, esophageal varices, and Mallory-Weis tears.
Nursing Implications
The nurse should do the following for clients who are taking expectorants and mucolytics:
- Prior to administering, assess the client’s medical history, current drug list, and allergies for potential interactions and contraindications.
- Assess the client’s respiratory status for signs of respiratory distress that indicate the need for additional evaluation and treatment. Also, identify the underlying reason for the cough to ensure the client is receiving the appropriate treatment.
- Assess the client’s cough including the frequency and amount and type of sputum.
- Educate the client on adverse effects of expectorants including headache, dizziness, nausea, and vomiting.
- Educate the client on adverse effects of mucolytics including fever, tachycardia, and pharyngitis.
- Monitor vital signs for tachycardia or fever for clients taking mucolytics.
- Clients receiving acetylcysteine should be monitored closely for bronchospasm, especially if they have asthma, because they are at higher risk for bronchospasm.
- Provide client teaching regarding the drug and when to call the health care provider. See below for client teaching guidelines.
Client Teaching Guidelines
The client taking an expectorant or mucolytic should:
- Take the drugs as prescribed and only for the time indicated.
- Be sure to drink fluids to help loosen secretions.
- Increase deep breathing exercises to assist with secretion movement.
- Report any adverse effects.
- Notify the health care provider if symptoms last longer than one week, become worse, or are accompanied by other symptoms.