Learning Objectives

Upon completion of this chapter, you will be able to:

1. Outline the underlying physiological events that occur with upper respiratory disorders.

2. Discuss the use of drugs that act on the upper respiratory tract across the lifespan.

3. Describe the therapeutic actions, indications, pharmacokinetics, contraindications, most common adverse effects, and important drug–drug interactions associated with drugs acting on the upper respiratory tract.

4. Compare and contrast the prototype drugs with other agents in their class and with other classes of drugs that act on the upper respiratory tract.

5. Outline the nursing considerations, including important teaching points, for patients receiving drugs acting on the upper respiratory tract.

Key Terms

Drug List

The drugs that are described in this chapter affect the respiratory system to treat symptoms of allergic or nonallergic rhinitis as well as cough and other symptoms from the common cold, influenza, and other respiratory disorders. They are designed for symptom relief and to keep the respiratory airways patent. They are not designed to treat or cure infection. Figure 54.1 displays the sites of action of these drugs. Figure 54.2 shows the structures of the upper respiratory tract.

Antitussives

Antitussives are drugs that suppress the cough reflex (Table 54.1). Many disorders of the respiratory tract, including the common cold, sinusitis, pharyngitis, and pneumonia, are accompanied by an uncomfortable, unproductive cough. Persistent coughing can be exhausting and can cause muscle strain and further irritation of the respiratory tract. A cough that occurs without the presence of any active disease process or persists aft er treatment may be a symptom of another disease process and should be investigated before any medication is given to alleviate it. Box 54.1 discusses the use of antitussives and other drugs acting on the upper respiratory tract in various age groups.

Therapeutic Actions and Indications

The traditional antitussives include codeine (generic), hydrocodone (generic), and dextromethorphan (generic), which act directly on the medullary cough center of the brain to depress the cough reflex. Because they are centrally acting, they are not the drugs of choice for anyone who has a head injury or who could be impaired by central nervous system (CNS) depression. Codeine and hydrocodone are opioid agonists that are primarily indicated for pain relief (see Chapter 26). They are used as cough suppressant medications in several combination formulations (Tuxarin ER, Hycodan, and others). They are controlled substances, designated schedule II when used alone and schedule V when used in combination and low amounts.

Other antitussives have a direct effect on the respiratory tract. Benzonatate (Tessalon) acts as a local anesthetic on the respiratory passages, lungs, and pleurae, blocking the effectiveness of the stretch receptors that stimulate a cough reflex.

Pharmacokinetics

Codeine, hydrocodone, and dextromethorphan are rapidly absorbed, metabolized in the liver, and excreted in the urine. They cross the placenta and enter human milk. Benzonatate is metabolized in the liver and excreted in the urine. These drugs should not be used during pregnancy and lactation (see “Contraindications and Cautions”).

Contraindications and Cautions

Antitussives are contraindicated in patients who need to cough to maintain the airways (e.g., postoperative patients and those who have undergone abdominal or thoracic surgery) to avoid respiratory distress. Careful use is recommended for patients with asthma and emphysema because cough suppression in these patients could lead to an accumulation of secretions and a loss of respiratory reserve. Caution should also be used in patients who are hypersensitive to or have a history of addiction to narcotics (codeine, hydrocodone). Codeine and hydrocodone are narcotics and have addiction potential. Patients who need to drive or be alert should use codeine, hydrocodone, and dextromethorphan with extreme caution because these drugs can cause sedation and drowsiness. These drugs should not be used during pregnancy and lactation because of the potential for adverse effects on the fetus or baby, including sedation and CNS depression.

Adverse Effects

Traditional antitussives have a drying effect on the mucous membranes and can increase the viscosity of respiratory tract secretions. Because they affect centers in the brain, these antitussives are associated with CNS adverse effects, including respiratory depression, drowsiness, and sedation. Other common side effects are nausea, vomiting, and constipation (Fig. 54.3). There is risk of addiction and dependence with the opioid substances. Locally acting antitussives are associated with gastrointestinal (GI) upset, headache, feelings of congestion, and sometimes dizziness. However, when taken at recommended doses, the adverse effects are generally mild.

Clinically Important Drug–Drug Interactions

Dextromethorphan should not be used with monoamine oxidase (MAO) inhibitors; hypotension, fever, nausea, myoclonic jerks, and coma could occur. Concurrent use of the opioid medications with other medications or substances (like alcohol) can increase the risk of respiratory depression, sedation, coma, and even death.

Box 54.1 Focus on Drug Therapy Across the Lifespan

UPPER RESPIRATORY TRACT AGENTS

Children

These drugs are used frequently with children. Most of these agents have established pediatric guidelines. Care must be taken when these drugs are used with children because the risk of adverse effects, including sedation, confusion, and dizziness, is common with children. Cough and cold medications should not be used in children under 4 years of age and should be used with extreme caution in children 4 to 6 years of age.

Because many of these agents are available in OTC cold, flu, and allergy remedies, it is important to educate parents about reading labels and following dosing guidelines to avoid potentially serious accidental overdose. Parents should always be asked specifically whether they are giving the child an OTC or herbal remedy.

Parents should also be encouraged to implement nondrug measures to help the child cope with the upper respiratory problem—drinking plenty of fluids, using a humidifier, avoiding smoke-filled areas and contact with known allergens or irritants, and washing hands frequently during cold and fl u season.

Adults

Adults may inadvertently overdose on these agents when taking multiple OTC preparations to help them get through a cold or flu. They need to be questioned specifically about the use of OTC or herbal remedies before any of these drugs are advised or administered. Adults can also be encouraged to use nondrug measures to help them cope with the signs and symptoms.

The safety for the use of many of these drugs during pregnancy and lactation has not been established. There is a potential for adverse effects on the fetus related to blood flow changes and direct drug effects when the drugs cross the placenta. The drugs may enter human milk and may also alter fluid balance and milk production. It is advised that caution be used if one of these drugs is prescribed when the patient is breast or chestfeeding.

Older Adults

Older adults are frequently prescribed one of these drugs. It is common for older adults to develop adverse effects associated with the use of these drugs, including sedation, confusion, and dizziness. Safety measures may be needed if these effects interfere with the patient’s mobility and balance.

Older adults also are more likely to have renal and/or hepatic impairment related to underlying medical conditions, which could interfere with the metabolism and excretion of these drugs. The dose for older adults may need to be started at a lower level if there is renal and/or hepatic impairment. The patient should be monitored closely, and dose adjustment should be based on the patient’s response.

These patients also need to be alerted to the potential for medication interactions when using OTC preparations and should be advised to check with their health care provider before beginning any OTC drug regimen.

Nursing Considerations for Patients Receiving Antitussives

Assessment: History and Examination

Assess for possible contraindications or cautions: any history of allergy to any component of the drug or drug vehicle to avoid allergic reactions; cough that persists longer than 1 week or is accompanied by other signs and symptoms, which could indicate a serious underlying medical condition that should be addressed before suppressing symptoms; and pregnancy or lactation because of the potential for adverse effects on the fetus or baby.
Perform a physical examination to establish baseline data for assessing the effectiveness of the drug and the occurrence of any adverse effects associated with drug therapy.
Monitor temperature to evaluate for possible underlying infection.
Assess respirations and adventitious sounds to assess drug effectiveness and to monitor for accumulation of secretions.
Evaluate orientation and affect to monitor for CNS effects of the drug.

Nursing Conclusions

Nursing conclusions related to drug therapy might include

Ineffective airway clearance related to suppression of the cough reflex
Altered sensory perception related to CNS effects
Knowledge deficit regarding drug therapy

Planning

The patient will receive the best therapeutic effect from the drug therapy.
The patient will have limited adverse effects from the drug therapy.
The patient will have an understanding of the drug therapy, adverse effects to anticipate, and measures to relieve discomfort and improve safety.

Intervention With Rationale

Ensure that the drug is not taken any longer than recommended to prevent serious adverse effects and increased respiratory tract problems.
Arrange for further medical evaluation for coughs that persist or are accompanied by high fever, rash, or excessive secretions to detect the underlying cause of the cough and to arrange for appropriate treatment of the underlying problem.
Provide other measures to help relieve cough (e.g., humidity, cool temperatures, fluids, use of topical lozenges) as appropriate.
Provide thorough patient teaching, including the drug name and prescribed dosage, measures to help avoid adverse effects, warning signs that may indicate problems, and the need for periodic monitoring and evaluation, to enhance patient knowledge about drug therapy and to promote adherence.
Offer support and encouragement to help the patient cope with the disease and the drug regimen.

Evaluation

Monitor patient response to the drug (control of nonproductive cough)
Monitor for adverse effects (respiratory depression, dizziness, sedation, GI symptoms).
Evaluate the effectiveness of the teaching plan (patient can name drug, dosage, adverse effects to watch for and specific measures to avoid them, and measures to take to increase the effectiveness of the drug.)
Monitor the effectiveness of other measures to relieve cough.

● Antitussive drugs suppress the cough reflex by acting centrally to suppress the respiratory cough center or locally as an anesthetic or to increase secretion and buffer irritation.

● Antitussive drugs can cause CNS depression, including drowsiness and sedation.

● Antitussive drugs should be used with caution in any situation in which coughing could be important for clearing the airways.

Decongestants

Decongestants decrease the overproduction of secretions by causing local vasoconstriction to the upper respiratory tract (Table 54.2). Th is vasoconstriction leads to a shrinking of swollen mucous membranes and tends to open clogged nasal passages, providing relief from the discomfort of a blocked nose and promoting drainage of secretions and improved airflow. An adverse effect that accompanies frequent or prolonged use of these drugs is a rebound congestion, technically called rhinitis medicamentosa. The reflex reaction to vasoconstriction is a rebound vasodilation, which oft en leads to prolonged overuse of decongestants.

Decongestants are usually adrenergics or sympathomimetics (see Chapter 30). Topical steroids are also used as decongestants, though they take several weeks to become effective and are more oft en used in cases of chronic rhinitis.

Topical Nasal Decongestants

Topical nasal decongestants include naphazoline (Privine), oxymetazoline (Afrin and others), phenylephrine (Coricidin and many others), tetrahydrozoline (Tyzine), and xylometazoline (Otrivin). Many of these are available as over-the-counter (OTC) preparations. The choice of a topical nasal decongestant varies among people. Some patients may have no response to one and respond well to another.