ch. 54
Tucker Chapter 54: Drugs Acting on the Upper Respiratory Tract
Key Terms
Antihistamines: drugs that block the release or action of histamine, a chemical released during inflammation that increases secretions and narrows airways
Antitussives: drugs that block the cough reflex
Decongestants: drugs that decrease the blood flow to the upper respiratory tract and decrease the production of secretions
Expectorants: drugs that increase productive cough to clear the airways
Mucolytics: drugs that increase or liquefy respiratory secretions to aid the clearing of the airways
Rebound Congestion: process that occurs when the nasal passages become congested as the effect of a decongestant drug wears off; patients tend to use more drug to decrease the congestion, and a vicious circle of congestion, drug, and congestion develops, leading to abuse of the decongestant; also called rhinitis medicamentosa
Rhinitis Medicamentosa: reflex reaction to vasoconstriction caused by decongestants; a rebound vasodilation that often leads to prolonged overuse of decongestants; also called rebound congestion
ANTITUSSIVES
benzonatate
codeine
dextromethorphan
hydrocodone
DECONGESTANTS
Topical Nasal Decongestants
naphazoline
oxymetazoline
phenylephrine
tetrahydrozoline
xylometazoline
Oral Decongestants
Phenylephrine
Pseudoephed
Steroid Nasal Decongestants
beclomethasone
budesonide
flunisolide
fluticasone
triamcinolone
ANTIHISTAMINES First Generation
brompheniramine
carbinoxamine
chlorpheniramine
clemastine
cyproheptadine
dexchlorpheniramine
dimenhydrinate
hydroxyzine
meclizine
promethazine
triprolidine
Second Generation (Nonsedating)
azelastine
cetirizine
desloratadine
fexofenadine
levocetirizine
loratadine
EXPECTORANT
Guaifenesin
MUCOLYTICS
acetylcysteine
dornase alfa
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.
Antitussives are drugs that suppress the cough reflex. 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 after treatment may be a symptom of another disease process and should be investigated before any medication is given to alleviate it. 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. 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. 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 flu 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 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. Prototype Summary: Dextromethorphan Indications: Reduce symptoms of cough. Actions: Depresses the cough center in the medulla to control cough spasms. Pharmacokinetics: Route Onset Peak Duration Oral 25–30 min 2 h 3–6 h T1/2: 2 to 4 hours; metabolized in the liver and excreted in the urine. Adverse Effects: Dizziness, respiratory depression, nausea, dry mouth. 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. Key Points 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.This 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 often 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 often 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. therapeutic actions and indications Topical decongestants are sympathomimetics, meaning they imitate the effects of the sympathetic nervous system to cause vasoconstriction, leading to decreased edema and inflammation of the nasal membranes. They are available as nasal sprays that are used to relieve the discomfort of nasal congestion that accompanies the common cold, sinusitis, and allergic rhinitis. These drugs can also be used when dilation of the nares is desired to facilitate medical examination or to relieve the pain and congestion of otitis media. Opening the nasal passage allows better drainage of the eustachian tube, relieving pressure in the middle ear. ADMINISTERING NASAL MEDICATIONS Proper administration technique is important for assuring that drugs given nasally have the desired therapeutic effect. It is important to periodically check the nares for any signs of erosion or lesions, which could allow systemic absorption of the drug. Most patients prefer to self-administer nasal drugs, so patient teaching is important. Explain the technique, and then observe the patient using the technique. Nasal Spray Teach the patient to sit upright and press a finger over one naris to close it. Hold the spray bottle upright and place the tip of the bottle about half an inch into the open naris. Firmly squeeze the bottle to deliver the drug. Repeat with the other naris. The patient should be encouraged to refrain from blowing their nose soon after administration so as not to expel the medication. pharmacokinetics Because these drugs are applied topically, the onset of action is almost immediate and there is less chance of systemic effects. Although they are not generally absorbed systemically, any portion of these topical decongestants that is absorbed is metabolized in the liver and excreted in the urine. See Box 54.2 for tips on how to teach patients to use these medications. contraindications and cautions Caution should be used when there is any lesion or erosion in the mucous membranes that could lead to systemic absorption. Caution should also be used in patients with any condition that might be exacerbated by sympathetic activity, such as glaucoma, hypertension, diabetes, thyroid disease, coronary disease, or prostate problems, because these agents have adrenergic properties. Because there are no studies regarding the effects of these topical drugs in pregnancy or lactation, if used during pregnancy or lactation, caution is advised. Decongestants Decongestants decrease the overproduction of secretions by causing local vasoconstriction to the upper respiratory tract (Table 54.2). This 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 often 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 often 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. p. 961 p. 962 Table 54.2 Drugs in Focus: Decongestants Drug Name Usual Dosage Usual Indications Topical Nasal Decongestants naphazoline (Privine) Adult and pediatric (>12 y): 1–2 sprays into nostrils every 6 h as needed Relieves discomfort of nasal congestion associated with the common cold, sinusitis, and allergic rhinitis oxymetazoline (Afrin) Adult and pediatric (>6 y): 2–3 sprays or drops in each nostril b.i.d. Pediatric (2–5 y): 2–3 drops of 0.05% solution in each nostril b.i.d. Relieves discomfort of nasal congestion associated with the common cold, sinusitis, and allergic rhinitis phenylephrine (Coricidin) Adult and pediatric (>6 y): 1–2 sprays in each nostril q3–4h Pediatric (2–6 y): 2–3 drops of 0.125% solution in each nostril q4h as needed Relieves discomfort of nasal congestion associated with the common cold, sinusitis, and allergic rhinitis tetrahydrozoline (Tyzine) Adult and pediatric (>6 y): 2–4 drops in each nostril t.i.d. to q.i.d. Pediatric (2–6 y): 2–3 drops of 0.05% solution in each nostril q4–6h Relieves discomfort of nasal congestion associated with the common cold, sinusitis, and allergic rhinitis; relieves pressure of otitis media xylometazoline (Otrivin) Adult: 2–3 sprays or 2–3 drops in each nostril q8–10h (0.17% solution) Pediatric (2–12 y): 2–3 drops of 0.05% solution q8–12h Relieves discomfort of nasal congestion associated with the common cold, sinusitis, and allergic rhinitis; relieves pressure of otitis media Oral Decongestant phenylephrine (Neo-Synephrine Nasal) Adult and pediatric: Dose varies based on age and combination product Decreases nasal congestion associated with the common cold, and allergic rhinitis; relieves pain and congestion of otitis media pseudoephedrine (Sudafed) Adult: 60 mg PO q4–6h Pediatric (6–12 y): 30 mg PO q4–6h Pediatric (2–5 y): 15 mg PO q4–6h Pediatric (1–2 y): 0.02 mL/kg PO q4–6h Pediatric (3–12 mo): 3 drops/kg PO q4–6h Decreases nasal congestion associated with the common cold, and allergic rhinitis; relieves pain and congestion of otitis media Steroid Nasal Decongestants beclomethasone (Beconase AQ, Qnasl) Adult and pediatric: 1-2 inhalations in each nostril q.d. or b.i.d. Relieves symptoms of seasonal or perennial allergic and nonallergic (vasomotor) rhinitis; relieves inflammation following removal of nasal polyps budesonide (Rhinocort) Adult and pediatric (>6 y): 1 spray in each nostril daily Relieves symptoms of seasonal or perennial allergic and nonallergic (vasomotor) rhinitis; relieves inflammation following removal of nasal polyps flunisolide (generic) Adult: 2 sprays in each nostril b.i.d. Pediatric (6–14 y): 1 spray in each nostril t.i.d. to two sprays in each nostril b.i.d. Relieves symptoms of seasonal or perennial allergic and nonallergic (vasomotor) rhinitis; relieves inflammation following removal of nasal polyps fluticasone (Flonase Allergy Relief) Adult and pediatric (4–11 y): 2 sprays in each nostril daily Relieves symptoms of seasonal or perennial allergic and nonallergic (vasomotor) rhinitis; relieves inflammation following removal of nasal polyps triamcinolone (Nasacort Allergy 24 Hour) Adult: 2 sprays in each nostril every day Pediatric: 1 spray in each nostril daily Relieves symptoms of seasonal or perennial allergic and nonallergic (vasomotor) rhinitis; relieves inflammation following removal of nasal polyps therapeutic actions and indications Topical decongestants are sympathomimetics, meaning they imitate the effects of the sympathetic nervous system to cause vasoconstriction, leading to decreased edema and inflammation of the nasal membranes. They are available as nasal sprays that are used to relieve the discomfort of nasal congestion that accompanies the common cold, sinusitis, and allergic rhinitis. These drugs can also be used when dilation of the nares is desired to facilitate medical examination or to relieve the pain and congestion of otitis media. Opening the nasal passage allows better drainage of the eustachian tube, relieving pressure in the middle ear. Focus on Patient and Family Teaching ADMINISTERING NASAL MEDICATIONS Proper administration technique is important for assuring that drugs given nasally have the desired therapeutic effect. It is important to periodically check the nares for any signs of erosion or lesions, which could allow systemic absorption of the drug. Most patients prefer to self-administer nasal drugs, so patient teaching is important. Explain the technique, and then observe the patient using the technique. Nasal Spray Teach the patient to sit upright and press a finger over one naris to close it. Hold the spray bottle upright and place the tip of the bottle about half an inch into the open naris. Firmly squeeze the bottle to deliver the drug. Repeat with the other naris. The patient should be encouraged to refrain from blowing their nose soon after administration so as not to expel the medication. pharmacokinetics Because these drugs are applied topically, the onset of action is almost immediate and there is less chance of systemic effects. Although they are not generally absorbed systemically, any portion of these topical decongestants that is absorbed is metabolized in the liver and excreted in the urine. Contraindications and cautions Caution should be used when there is any lesion or erosion in the mucous membranes that could lead to systemic absorption. Caution should also be used in patients with any condition that might be exacerbated by sympathetic activity, such as glaucoma, hypertension, diabetes, thyroid disease, coronary disease, or prostate problems, because these agents have adrenergic properties. Because there are no studies regarding the effects of these topical drugs in pregnancy or lactation, if used during pregnancy or lactation, caution is advised. adverse effects Adverse effects associated with topical decongestants include local stinging and burning, which may occur the first few times the drug is used. If the sensation does not pass, use should be discontinued because it may indicate lesions or erosion of the mucous membranes. Use for longer than 3 to 5 days can lead to a rebound congestion (also called rhinitis medicamentosa), which occurs when the nasal passages become congested as the drug effect wears off. As a result, patients tend to use more drug to decrease the congestion, thus initiating a cycle of congestion–drug–congestion, which leads to abuse of the decongestant. Sympathomimetic effects (e.g., increased pulse and blood pressure; urinary retention) should be monitored because some systemic absorption may occur, though these effects are less likely with topical administration than with other routes. clinically important drug–drug interactions The use of topical nasal decongestants with other medications that affect the sympathetic nervous system should be monitored carefully. Prototype Summary: Tetrahydrozoline Indications: Symptomatic relief of nasal and nasopharyngeal mucosal congestion due to the common cold, hay fever, or other respiratory allergies. Actions: Sympathomimetic effects, partly due to release of norepinephrine from nerve terminals; vasoconstriction leads to decreased edema and inflammation of the nasal membranes. Pharmacokinetics: Route Peak Duration Topical (nasal spray) 5–10 min 6–10 h. T1/2: Unknown; metabolized in the liver and excreted in the urine; little is usually absorbed for systemic metabolism. Adverse Effects: Disorientation, confusion, light-headedness, nausea, vomiting, fever, dyspnea, and rebound congestion. Nursing Considerations for Patients Receiving Topical Nasal Decongestants Assessment: History and Examination Assess for possible contraindications or cautions: any history of allergy to the drug or a component of the drug vehicle; glaucoma, hypertension, diabetes, thyroid disease, coronary disease, and prostate problems, all of which could be exacerbated by the sympathomimetic effects; and pregnancy or lactation, which require cautious use of the drug. 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. Assess skin color and temperature to assess sympathetic response. Evaluate orientation and reflexes to evaluate CNS effects of the drug. Monitor pulse, blood pressure, and cardiac auscultation to assess cardiovascular (CV) and sympathomimetic effects. Evaluate respirations and adventitious breath sounds to assess the effectiveness of the drug and potential excess effect. Monitor urinary output to evaluate for urinary retention. Evaluate nasal mucous membrane to monitor for lesions that could lead to systemic absorption and to evaluate decongestant effect. Nursing Conclusions Nursing conclusions related to drug therapy might include Impaired comfort related to GI, CNS, or local effects of drug Altered sensory perception (kinesthetic) related to CNS effects (less likely with this route of administration) 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 Teach the patient the proper administration of the drug to ensure therapeutic effect. The patient should be instructed to clear the nasal passages before use. Some formulations are administered with the head upright; for others, the patient should tilt their head slightly forward. The medication should be sprayed into the open nostril. The patient should breathe in through their nose. It is recommended that the patient refrain from blowing their nose for several minutes after administration. Caution the patient not to use the drug for longer than 5 days and to seek medical care if signs and symptoms persist after that time to facilitate detection of underlying medical conditions that may require treatment. Caution the patient that these drugs are found in many OTC preparations and that care should be taken not to inadvertently combine drugs with the same ingredients, which could lead to overdose. Provide safety measures if dizziness or sedation occurs as a result of drug therapy, to prevent patient injury. Institute other measures to help relieve the discomfort of congestion (e.g., use of a humidifier, increased fluid intake, cool environment, avoidance of smoke-filled areas) 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 (relief of nasal congestion). Monitor for adverse effects (local burning and stinging; adrenergic effects such as increased pulse, blood pressure, urinary retention, cool and clammy skin). Evaluate the effectiveness of the teaching plan (patient can name drug, dosage, adverse effects to watch for and specific measures to avoid them, measures to take to increase the effectiveness of the drug, proper administration technique). Monitor the effectiveness of comfort and safety measures and adherence to the regimen. Oral Decongestants The oral decongestants currently available for use are pseudoephedrine and phenylephrine. therapeutic actions and indications Oral decongestants are drugs that are taken orally to decrease nasal congestion related to the common cold, sinusitis, and allergic rhinitis. They are also used to relieve the pain and congestion of otitis media. Opening of the nasal passage allows better drainage of the eustachian tube, relieving pressure in the middle ear. Oral decongestants shrink the nasal mucous membrane by stimulating the alpha-adrenergic receptors in the nasal mucous membranes. This shrinkage results in a decrease in membrane size, promoting drainage of the sinuses and improving airflow. pharmacokinetics Pseudoephedrine is generally well absorbed and reaches its peak level quickly, in 20 to 45 minutes. It is widely distributed in the body, metabolized in the liver, and primarily excreted in the urine. Phenylephrine is available in a nasal spray and combination products. contraindications and cautions Because these medications have adrenergic properties, caution should be used in patients with any condition that might be exacerbated by sympathetic activity, such as glaucoma, hypertension, diabetes, thyroid disease, coronary disease, and prostate problems. Because there are no adequate studies about use during pregnancy and lactation, such use should be reserved for situations in which the benefit to the patient outweighs any potential risk to the fetus or neonate. The ingredient pseudoephedrine has been used to make methamphetamine, so there are federal and state laws restricting sales amounts. Medications with pseudoephedrine are designated “behind-the-counter” instead of OTC. To procure a behind-the-counter medication, a patient does not need a prescription. However, the medications are sold in limited quantities and a pharmacist must allow access. This policy helps to limit the amount of pseudoephedrine that a person can buy. There are many cough and allergy OTC products that contain a combination of medications, so patients need to be able to read labels to be cautious when treating these symptoms without assistance from a provider and/or pharmacist. adverse effects associated with these decongestants include rebound congestion. Because these drugs may be taken systemically, adverse effects related to the sympathomimetic effects are more likely to occur, including feelings of anxiety, tenseness, restlessness, tremors, hypertension, arrhythmias, sweating, and pallor. Pseudoephedrine is found in many “behind-the-counter” cold and flu preparations, and phenylephrine is OTC, so care must be taken to avoid inadvertent overdose when more than one such drug is used. There are safety measures in place limiting access to pseudoephedrine clinically important drug–drug interactions Many behind-the-counter and OTC products, including cold remedies, allergy medications, and flu remedies, may contain pseudoephedrine or phenylephrine. Taking such products concurrently can cause serious adverse effects. Teach patients to read the labels to avoid inadvertent overdose. Prototype Summary: Pseudoephedrine Indications: Temporary relief of nasal congestion caused by the common cold, hay fever, and sinusitis; promotion of nasal and sinus drainage; relief of eustachian tube congestion. Actions: Sympathomimetic effects; causes vasoconstriction in mucous membranes of nasal passages resulting in their shrinkage, which promotes drainage and improvement in ventilation. Pharmacokinetics: Route Onset Duration Oral 30 min 4–6 h T1/2: 7 hours; metabolized in the liver and excreted in the urine. Adverse Effects: Anxiety, restlessness, headache, dizziness, drowsiness, vision changes, seizures, hypertension, arrhythmias, pallor, nausea, vomiting, urinary retention, respiratory difficulty. Nursing Considerations for Patients Receiving an Oral Decongestant Assessment: History and Examination Assess for possible contraindications or cautions: any history of allergy to the drug and pregnancy or lactation, which are contraindications to drug use; hypertension or coronary artery disease, which require cautious use; and hyperthyroidism, diabetes mellitus, or prostate enlargement, all of which could be exacerbated by these drugs. 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. Assess skin color and lesions to monitor for adverse reactions. Evaluate orientation, reflexes, and affect to monitor CNS effects of the drug. Monitor blood pressure, pulse, and auscultation to assess CV stimulations. Evaluate respiration and adventitious sounds to monitor drug effectiveness. Monitor urinary output to evaluate for urinary retention. Nursing Conclusions Nursing conclusions related to drug therapy might include Impaired comfort related to GI, CNS, or skin effects of the drug Altered tissue perfusion related to sympathomimetic actions of the drug Altered sensory perception (kinesthetic) 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 Note that these drugs are found in many behind-the-counter and OTC products, especially combination cold and allergy preparations; care should be taken to prevent inadvertent overdose or excessive adverse effects. Provide safety measures as needed if CNS effects occur, to prevent patient injury. Monitor pulse, blood pressure, and cardiac response to the drug, especially in patients who are at risk for adverse effects with sympathetic stimulation, to detect adverse effects early and arrange to reduce dose or discontinue the drug. Encourage the patient not to use these drugs for longer than 1 week and to seek medical evaluation if symptoms persist after that time to encourage the detection of underlying medical conditions that could be causing these symptoms and to arrange for appropriate treatment. 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 (improvement in nasal congestion). Monitor for adverse effects (sympathomimetic reactions, including increased pulse, blood pressure, pallor, sweating, arrhythmias, feelings of anxiety, tension, urinary retention, constipation). 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 comfort and safety measures and adherence to the regimen. Steroid Nasal Decongestants Topical nasal steroid decongestants include beclomethasone (Beconase AQ and others), budesonide (Rhinocort), flunisolide (generic), fluticasone (Flonase Allergy Relief), and triamcinolone (Nasacort Allergy 24 Hour). therapeutic actions and indications Topical nasal steroid decongestants are used for the treatment of allergic rhinitis and to relieve inflammation after the removal of nasal polyps. They are first-line medications for nasal congestion. The exact mechanism of action of topical steroids is not known. Their anti-inflammatory action results from their ability to produce a direct local effect that blocks many of the complex reactions responsible for the inflammatory response. pharmacokinetics The onset of action is not immediate, and these drugs may actually require up to 1 week to cause any changes. If no effects are seen after 3 weeks, the drug should be discontinued. Because these drugs are not generally absorbed systemically, their pharmacokinetics are not reported. If they were to be absorbed systemically, they would have the same pharmacokinetics as other steroids contraindications and cautions Because nasal steroids block the inflammatory response, their use is contraindicated in the presence of acute infections. Increased incidence of Candida albicans infection has been reported with their use related to the anti-inflammatory and anti-immune activities associated with steroids. Caution should be used in any patient who has an active infection, including tuberculosis, because systemic absorption would interfere with the inflammatory and immune responses. Patients using nasal steroids should avoid exposure to any airborne infection, such as chickenpox or measles. As with all drugs, caution should always be used when taking these drugs during pregnancy or lactation, but because the systemic absorption of these drugs is minimal, they are often used during pregnancy and lactation. adverse effects Because they are applied topically, there is less chance of systemic absorption and associated adverse effects. The most common adverse effects are local burning, irritation, stinging, dryness of the mucosa, and headache. Because healing is suppressed by steroids, patients who have recently experienced nasal surgery or trauma should be monitored closely until healing has occurred. clinically important drug–drug interactions The steroid nasal decongestants are applied topically and thus do not typically interact with other systemic medications. However, concurrent nasal medications should not be administered without discussion with a health care provider. Prototype Summary: Flunisolide Indications: Relief of the symptoms of seasonal or perennial allergic and nonallergic (vasomotor) rhinitis; relief of inflammation following removal of nasal polyps. Actions: Anti-inflammatory action, which results from the ability to produce a direct local effect that blocks many of the complex reactions responsible for the inflammatory response. Pharmacokinetics: Route Onset Peak Duration Topical (nasal spray) Fast <30 min 10–30 min 4–6 h T1/2: Not generally absorbed systemically. Adverse Effects: Local burning, irritation, stinging, dryness of the mucosa, headache, increased risk of infection. Nursing Considerations for Patients Receiving Steroid Nasal Decongestants Assessment: History and Examination Assess for possible contraindications or cautions: any history of allergy to steroid drugs or any components of the drug, which would be a contraindication, and acute infection, which would require cautious use. 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. Perform an intranasal examination to determine the presence of any lesions that would increase the risk of systemic absorption of the drug. Monitor temperature to monitor for the possibility of acute infection. Nursing Conclusions Nursing conclusions related to drug therapy might include Impaired comfort related to local effects of the drug Infection risk related to suppression of inflammatory reaction 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 Teach the patient how to administer these drugs properly, which is important to ensure effectiveness and prevent systemic effects. A variety of preparations are available, including sprays and aerosols. Advise the patient about the proper administration technique for whichever preparation is recommended. Have the patient clear the nasal passages before using the drug to improve its effectiveness. Encourage the patient to continue using the drug regularly, even if results are not seen immediately, because benefits may take 2 to 3 weeks to appear. Monitor the patient for the development of acute infection that would require medical intervention. Encourage the patient to avoid areas where airborne infections could be a problem because steroid use decreases the effectiveness of the immune and inflammatory responses. 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 (relief of nasal congestion). Monitor for adverse effects (local burning and stinging). 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 comfort and safety measures and adherence to the regimen. Key Points Decongestants cause local vasoconstriction, thereby reducing blood flow to the mucous membranes of the nasal passages and sinus cavities. Rebound vasodilation (rhinitis medicamentosa) is an adverse effect of excessive or long-term decongestant use. Topical nasal decongestants are preferred for patients who need to avoid the systemic adrenergic effects associated with oral decongestants. Topical nasal steroid decongestants block the inflammatory response and are preferred for patients with allergic rhinitis. Antihistamines block the release or action of histamine, a chemical released during inflammation that increases secretions and narrows airways. Antihistamines are found in multiple OTC preparations that are designed to relieve respiratory symptoms and to treat symptoms of allergies. When choosing an antihistamine, the individual patient’s reaction to the drug is usually the governing factor. Because first-generation antihistamines have greater anticholinergic effects with resultant drowsiness, a person who needs to be alert should be given one of the second-generation, less-sedating antihistamines. In some people, the second-generation antihistamines are also sedating, so care must be taken until the patient knows what response will occur. Because of their OTC availability, these drugs are often misused to treat colds and influenza First-generation antihistamines include brompheniramine (J-Tan and others), carbinoxamine (Karbinal ER), chlorpheniramine (Aller-Chlor and others), clemastine (Dayhist Allergy), cyproheptadine (generic), dexchlorpheniramine (generic), dimenhydrinate (Dimentabs and others), diphenhydramine (Benadryl and others), hydroxyzine (Vistaril and others), meclizine (Antivert), promethazine (Phenergan), and triprolidine (generic). Second-generation antihistamines include azelastine (Astelin, Astepro), cetirizine (Zyrtec), desloratadine (Clarinex), fexofenadine (Allegra), levocetirizine (Xyzal), loratadine (Claritin), and olopatadine (Patanase). Therapeutic Actions and Indications Antihistamines selectively block the effects of histamine at the histamine-1 receptor sites, decreasing the allergic response. They also have anticholinergic and antipruritic effects. Antihistamines are used for the relief of symptoms associated with seasonal and perennial allergic rhinitis, allergic conjunctivitis, uncomplicated urticaria, and angioedema. They are also used for the amelioration of allergic reactions to blood or blood products, for relief of discomfort associated with dermographism, and as adjunctive therapy in anaphylactic reactions. They are most effective for symptoms of itching, sneezing, and rhinorrhea. Some can be used to treat or prevent motion sickness and insomnia. Other uses that are being explored include relief of exercise- and hyperventilation-induced asthma and histamine-induced bronchoconstriction in asthmatics. They are most effective if used before the onset of symptoms. Pharmacokinetics Antihistamines are well absorbed orally with an onset of action ranging from 1 to 3 hours. They are generally metabolized in the liver, with excretion in the feces and urine. These drugs cross the placenta and enter human milk (see “Contraindications and Cautions”). Contraindications and Cautions Antihistamines are contraindicated during pregnancy or lactation unless the benefit to the patient clearly outweighs the potential risk to the fetus or baby. Some of the medications have higher safety profiles than others, so medication labels should be evaluated to determine risk of use during pregnancy and/or lactation. Some should be used with caution, and there may need to be dosage adjustment for patients with renal or hepatic impairment, which could alter the metabolism and excretion of the drug. Special care should be taken when some of the first-generation antihistamines are used by a patient with a history of arrhythmias or prolonged QT intervals because fatal cardiac arrhythmias have been associated with the use of certain antihistamines and drugs that increase QT intervals, including erythromycin Following reports of serious and even fatal adverse effects when OTC cough and cold medicines were used in children under the age of 2 years, the FDA held meetings to evaluate the safety and efficacy of the use of these products in young children. The evidence continues to be evaluated, and current recommendations include the following: Do not give OTC cough and cold products to children younger than 2 years of age unless specifically instructed to do so by a health care provider. Cough medications that contain the opioids codeine and hydrocodone are not recommended for children younger than 18 years of age. Do not give your child OTC cough and cold medicines made for adults; look for children’s, infant’s, or pediatric use on the label. Always check the active ingredients on the drug label. Be careful if you are giving your child more than one cough and cold medicine; many contain the same active ingredients, and overdose can occur. Carefully follow the directions in the “Drug Facts” section of the label and follow the directions for how often you can give the drug. Use the measuring spoons or cups that come with the medicine; do not use household spoons, which can vary widely in the amount of medicine they hold. Use OTC cough and cold medicines with child-proof caps and keep them out of the reach of children to avoid possible overdose. Consult your health care provider; these drugs only treat signs and symptoms and do not cure any disease; contact your health care provider if the symptoms get worse. Do not use these products to make your child sleepy. Tell any health care provider taking care of your child the names of any OTC products that you are giving your child. Nondrug approaches to handling the symptoms of a cold include using a humidifier, making sure the child drinks plenty of fluids, use of a bulb syringe aspirator in younger children, use of saline nasal spray or drops to help with congestion, appropriate use of analgesics to help with any pain or discomfort, and positioning to promote drainage of fluids. If your child does not improve or continues to have a fever, consult your health care provider. Adverse Effects The adverse effects most often seen with antihistamine use are drowsiness and sedation (see “Critical Thinking Scenario” for additional information), though second-generation antihistamines are less sedating in many people. The anticholinergic effects that can be anticipated include drying of the respiratory and GI mucous membranes, GI upset and nausea, arrhythmias, dysuria, urinary hesitancy, and skin eruption and itching associated with dryness. Clinically Important Drug–Drug Interactions Drug–drug interactions vary among the antihistamines; for example, anticholinergic effects may be prolonged if diphenhydramine is taken with an MAO inhibitor, and the interaction of fexofenadine with ketoconazole or erythromycin may raise fexofenadine concentrations to toxic levels. Concurrent use with other CNS depressants can increase the sedative effect of the antihistamines. For more information, consult a nursing drug handbook or package insert for individual details. PATIENT TEACHING FOR K.E. Antihistamines are commonly used to treat the signs and symptoms of various allergic reactions. Because these drugs work throughout the body, their use can cause many systemic effects (e.g., dry mouth, dizziness, drowsiness, constipation). Some of the antihistamines have less risk for adverse effects compared to others. Take this drug only as prescribed. Do not increase the dose if symptoms are not relieved. Instead, consult your health care provider. Common effects of this drug include Drowsiness, dizziness: Do not drive or operate dangerous machinery if this occurs. Use caution to prevent injury. GI upset, nausea, vomiting, heartburn: Taking the drug with food may help this problem. Dry mouth: Frequent mouth care and sucking sugarless lozenges may help. thickening of the mucus, difficulty coughing, tightening of the chest: Use a humidifier, or if you do not have one, place pans of water throughout the house to increase the humidity of the room air; avoid smoke-filled areas; drink plenty of fluids. Report any of the following to your health care provider: difficulty breathing, rash, hives, difficulty voiding, abdominal pain, visual changes, and disorientation or confusion. Avoid the use of alcoholic beverages while you are taking this drug. Serious drowsiness or sedation can occur if these are combined. Avoid the use of any OTC medication without first checking with your health care provider. Several of these medications contain drugs that can interfere with the effectiveness of this drug, or they can contain similar drugs and you could experience toxic effects. Tell any doctor, nurse, or other health care provider involved in your care that you are taking this drug. Take this drug only as prescribed. Do not give this drug to anyone else, and do not take similar preparations that have been prescribed for someone else. Keep this drug and all medications out of the reach of children. Prototype Summary: Diphenhydramine Indications: Symptomatic relief of perennial and seasonal rhinitis, vasomotor rhinitis, allergic conjunctivitis, urticaria, and angioedema; also used for treating motion sickness and parkinsonism and as a nighttime sleep aid and to suppress coughs. Actions: Competitively blocks the effects of histamine at histamine-1 receptor sites; has atropinelike antipruritic and sedative effects. Pharmacokinetics: Route Onset Peak Duration Oral 15–30 min 1–4 h 4–7 h IM 20–30 min 1–4 h 4–8 h IV Rapid 30–60 min 4–8 h T1/2: 2.5 to 7 hours; metabolized in the liver and excreted in the urine. Adverse Effects: Drowsiness, sedation, dizziness, epigastric distress, thickening of bronchial secretions, urinary retention, rash, bradycardia. Nursing Considerations for Patients Receiving Antihistamines Assessment: History and Examination Assess for possible contraindications or cautions: any history of allergy to antihistamines, pregnancy or lactation, or prolonged QT interval, which are contraindications or cautions to the use of the drugs; and renal or hepatic impairment, which may require cautious use of the drug. 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. Assess the skin color, texture, and lesions to monitor for anticholinergic effects or allergy. Evaluate orientation, affect, and reflexes to monitor for changes due to CNS effects. Assess respirations and adventitious sounds to monitor for drug effects. Evaluate liver and renal function tests to monitor for factors that could affect the metabolism or excretion of the drug. Nursing Conclusions Nursing conclusions related to drug therapy might include Impaired comfort related to GI, CNS, or skin effects of the drug Altered sensory perception (kinesthetic) related to CNS effects Safety risk due to dizziness and/or sedation 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 Administer the drug on an empty stomach 1 hour before or 2 hours after meals to increase the absorption of the drug; the drug may be given with meals if GI upset is a problem. Note that the patient may have poor response to one of these agents but an effective response to another; the prescriber may need to try several different agents to find the one that is most effective. Because of the drying nature of antihistamines, patients often experience dry mouth; suggest sugarless candies or lozenges to relieve some of this discomfort. Provide safety measures as appropriate if CNS effects occur to prevent patient injury. Increase humidity and hydration to decrease the problem of thickened secretions and dry nasal mucosa. Provide skin care as needed if skin dryness and lesions become a problem to prevent skin breakdown. Caution the patient to avoid an excessive dose and to check OTC drugs for the presence of antihistamines, which are found in many OTC preparations and could cause toxicity. Caution the patient to avoid alcohol and other CNS depressants while taking these drugs because concurrent use can increase sedation. 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 (relief of the symptoms of allergic rhinitis). Monitor for adverse effects (skin dryness, GI upset, sedation and drowsiness, constipation, thickened secretions, glaucoma). 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 comfort and safety measures and adherence to the regimen. Key Points Antihistamines selectively block the effects of histamine at the histamine-1 receptor sites, decreasing the allergic response. Antihistamines are used for the relief of symptoms associated with seasonal and perennial allergic rhinitis, allergic conjunctivitis, uncomplicated urticaria, and angioedema. Patients taking antihistamines may have dryness of the skin and mucous membranes. The nurse should encourage them to drink plenty of fluids, use a humidifier if possible, avoid smoke-filled rooms, and use good skin care and moisturizers. Some first-generation antihistamines should be avoided with any patient who has a prolonged QT interval because serious cardiac complications and even death have occurred. Expectorants Expectorants increase productive cough to clear the airways. They liquefy lower respiratory tract secretions, reducing the viscosity of these secretions and making it easier for the patient to cough them up. Expectorants are available in many OTC combination preparations, making them widely available to the patient without advice from a health care provider. Currently, the only available expectorant sold outside of the combination formulations is guaifenesin (Mucinex). Therapeutic Actions and Indications Guaifenesin enhances the output of respiratory tract fluids by reducing the adhesiveness and surface tension of these fluids, allowing easier movement of the less viscous secretions. The results of this thinning of secretions are a more productive cough and enhanced patency of the respiratory airways. Pharmacokinetics Guaifenesin is rapidly absorbed with an onset of 30 minutes and a duration of 4 to 6 hours. Sites of metabolism and excretion have not been reported. Contraindications and Cautions This drug should not be used in patients with a known allergy to the drug to prevent hypersensitivity reactions, and it should be used with caution in pregnancy and lactation because of the potential for adverse effects on the fetus or baby and with persistent coughs, which could be indicative of underlying medical problems. Adverse Effects The most common adverse effects associated with expectorants are GI symptoms (e.g., nausea, vomiting, anorexia). Some patients experience headache, dizziness, or both. A rash may be a sign of an allergic reaction. The most important consideration in the use of these drugs is diagnosing the cause of the underlying cough. Prolonged use of OTC preparations could result in the masking of important symptoms of a serious underlying disorder. These drugs should not be used for more than 1 week; if the cough persists, encourage the patient to seek health care. Clinically Important Drug–Drug Interactions There are no known significant drug interactions with guaifenesin. However, patients should be cautioned that there may be drug interactions with other medications that guaifenesin is combined with in OTC formulations. Prototype Summary: Guaifenesin Indications: Symptomatic relief of respiratory conditions by thinning mucous secretions, promoting ability to expel mucous and decrease respiratory congestion. Actions: Enhances the output of respiratory tract fluid by reducing the adhesiveness and surface tension of the fluid, facilitating the removal of viscous mucus. Pharmacokinetics: Route Onset Peak Duration Oral 30 min Unknown 4–6 h T1/2: Unknown; metabolism and excretion are also unknown. Adverse Effects: Nausea, vomiting, headache, dizziness, rash. Nursing Considerations for Patients Receiving Expectorants Assessment: History and Examination Assess for possible contraindications or cautions: any history of allergy to the drug; persistent cough due to smoking, asthma, or emphysema, which would be cautions to the use of the drug; and productive cough lasting more than a week, which would indicate an underlying problem that should be evaluated. 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. Assess the skin for the presence of rash to monitor for any sign of allergic reaction. Monitor temperature to assess for an underlying infection. Assess respirations and adventitious sounds to evaluate the respiratory response to the drug effects. Monitor orientation and affect to monitor CNS effects of the drug. Nursing Conclusions Nursing conclusions related to drug therapy might include Impaired comfort related to GI, CNS, or skin effects of the drug Altered sensory perception (kinesthetic) 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 Caution the patient not to use these drugs for longer than 1 week and to seek medical attention if the cough persists after that time to evaluate for any underlying medical condition and to arrange for appropriate treatment. Advise the patient to take small, frequent meals to alleviate some of the GI discomfort associated with these drugs. Advise the patient to avoid driving or performing dangerous tasks if dizziness and drowsiness occur, to prevent patient injury. Alert the patient that these drugs may be found in OTC preparations and that care should be taken to avoid excessive doses. 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 (improved effectiveness of cough). Monitor for adverse effects (skin rash, GI upset, CNS effects). 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 comfort and safety measures and adherence to the regimen. Key Points Expectorants are drugs that liquefy respiratory tract secretions. They are used for the symptomatic relief of respiratory conditions in which thick mucus exacerbates cough and decreases airway patency. Guaifenesin is the only expectorant currently available. Care should be taken to avoid inadvertent overdose when using OTC and/or combination products that contain this drug. Mucolytics increase or liquefy respiratory secretions to aid the clearing of the airways in high-risk respiratory patients who are coughing up thick, tenacious secretions. Patients may be suffering from conditions such as chronic obstructive pulmonary disease (COPD), cystic fibrosis, pneumonia, or tuberculosis. Mucolytics include acetylcysteine (generic) and dornase alfa (Pulmozyme). Therapeutic Actions and Indications Acetylcysteine is used orally or intravenously to protect liver cells from being damaged during episodes of acetaminophen toxicity because it normalizes hepatic glutathione levels and binds with a reactive hepatotoxic metabolite of acetaminophen. Acetylcysteine affects the mucoproteins in the respiratory secretions by splitting apart disulfide bonds that are responsible for holding the mucus material together. The result is a decrease in the tenacity and viscosity of the secretions. Dornase alfa is a mucolytic prepared by recombinant DNA techniques that selectively break down respiratory tract mucus by separating extracellular DNA from proteins. It is used in cystic fibrosis, which is characterized by thick, tenacious mucous production. Pharmacokinetics The medication may be administered by nebulization or by direct instillation into the trachea via an endotracheal tube or tracheostomy. Acetylcysteine is metabolized in the liver and excreted somewhat in the urine. It is not known whether it crosses the placenta or enters human milk. Dornase alfa is metabolized by proteases, and its half-life is 3 to 4 hours. Contraindications and Cautions The medications are contraindicated in patients who have history of hypersensitivity reactions to the medications or components in the medications. Caution should be used with patients who have asthmaMucolytics Mucolytics (Table 54.5) increase or liquefy respiratory secretions to aid the clearing of the airways in high-risk respiratory patients who are coughing up thick, tenacious secretions. Patients may be suffering from conditions such as chronic obstructive pulmonary disease (COPD), cystic fibrosis, pneumonia, or tuberculosis. Mucolytics include acetylcysteine (generic) and dornase alfa (Pulmozyme). Therapeutic Actions and Indications Acetylcysteine is used orally or intravenously to protect liver cells from being damaged during episodes of acetaminophen toxicity because it normalizes hepatic glutathione levels and binds with a reactive hepatotoxic metabolite of acetaminophen. Acetylcysteine affects the mucoproteins in the respiratory secretions by splitting apart disulfide bonds that are responsible for holding the mucus material together. The result is a decrease in the tenacity and viscosity of the secretions. See Table 54.5 for usual indications. Dornase alfa is a mucolytic prepared by recombinant DNA techniques that selectively break down respiratory tract mucus by separating extracellular DNA from proteins. It is used in cystic fibrosis, which is characterized by thick, tenacious mucous production. See Table 54.5 for usual indications. See Box 54.5 for information about targeted treatment of cystic fibrosis. Pharmacokinetics The medication may be administered by nebulization or by direct instillation into the trachea via an endotracheal tube or tracheostomy. Acetylcysteine is metabolized in the liver and excreted somewhat in the urine. It is not known whether it crosses the placenta or enters human milk. Dornase alfa is metabolized by proteases, and its half-life is 3 to 4 hours. Contraindications and Cautions The medications are contraindicated in patients who have history of hypersensitivity reactions to the medications or components in the medications. Caution should be used with patients who have asthma due to potential for bronchospasm. There are no adequate human studies to evaluate risk during pregnancy or lactation, but there has been no evidence of fetal harm in animal studies. Adverse Effects Adverse effects most associated with mucolytic drugs include GI upset, stomatitis, rhinorrhea, bronchospasm, and occasionally a rash. Clinically Important Drug–Drug Interactions There are no known drug interactions with acetylcysteine or dornase alfa. Targeted Treatment of Cystic Fibrosis Between 2012 and 2019, several medications were approved by the FDA for treatment of cystic fibrosis. Ivacaftor (Kalydeco) and combination medications that include ivacaftor (Orkambi, Symdeko, and Trikafta) are designed as targeted treatment for patients with cystic fibrosiis. Ivacaftor is a cystic fibrosis transmembrane conductance regulator (CFTR) that facilitates increased chloride transport at the surface of epithelial cells in multiple organs. In cystic fibrosis patients taking this drug, the end result was improved lung function. Ivacaftor is approved for patients 4 months of age and older who have a type of CFTR gene mutation that is responsive to ivacaftor. If the patient’s genotype is not known, tests should be run to attempt to detect a CFTR mutation. The FDA has approved a cystic fibrosis mutation test that can be used to determine the appropriateness of this drug. It is an oral agent and needs to be used with caution in patients with liver impairment or those also using CYP3A inhibitors. The most common adverse effects include abdominal pain, rash, nausea, dizziness, headache, and sore throat. A serious but rare effect can be the development of noncongenital lens opacities/cataracts in pediatric patients. Prototype Summary: Acetylcysteine Indications: Mucolytic adjunctive therapy for abnormal, viscid, or inspissated mucous secretions in acute and chronic bronchopulmonary disorders; to lessen hepatic injury in cases of acetaminophen toxicity. Actions: Splits links in the mucoproteins contained in the respiratory mucus secretions, decreasing the viscosity of the secretions; protects liver cells from acetaminophen effects. Pharmacokinetics: Route Onset Peak Duration Instillation, inhalation 1 min 5–10 min 2–3 h Oral 30–60 min 1–2 h Unknown T1/2: 6.25 hours; metabolized in the liver and excreted in the urine. Adverse Effects: Nausea, stomatitis, urticaria, bronchospasm, rhinorrhea. Nursing Considerations for Patients Receiving Mucolytics Assessment: History and Examination Assess for possible contraindications or cautions: any history of allergy to the drugs and the presence of acute bronchospasm, which are contraindications to the use of these drugs. 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. Assess skin color and lesions to monitor for adverse reactions. Monitor blood pressure and pulse to evaluate cardiac response to drug treatment. Evaluate respirations and adventitious sounds to monitor drug effectiveness. Nursing Conclusions Nursing conclusions related to drug therapy might include Impaired comfort related to GI, CNS, or skin effects of the drug Altered sensory perception (kinesthetic) related to CNS effects Ineffective airway clearance related to bronchospasm 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 Avoid combining with other drugs in the nebulizer to avoid the formation of precipitates and the potential loss of effectiveness of either drug. Dilute the concentrate with sterile water for injection if buildup becomes a problem that could impede drug delivery. Note that patients receiving acetylcysteine by face mask should have the residue wiped off the face mask and off the face with plain water to prevent skin breakdown. Review use of the nebulizer with patients receiving dornase alfa at home to ensure the most effective use of the drug. Patients should be cautioned to store the drug in the refrigerator, protected from light. Caution cystic fibrosis patients receiving dornase alfa about the need to continue all therapies for their cystic fibrosis because dornase alfa is only a palliative therapy that improves respiratory symptoms and other therapies are still needed. 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 (improvement of respiratory symptoms and loosening of secretions). Monitor for adverse effects (CNS effects, skin rash, bronchospasm, and GI upset). 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 comfort and safety measures and adherence to the regimen. Key Points Mucolytics work to break down mucus to aid high-risk respiratory patients in coughing up thick, tenacious secretions. Dornase alfa is specific for the treatment of patients with cystic fibrosis, which is characterized by a thick, tenacious mucus production that can block airways. SUMMARY Antitussives are drugs that suppress the cough reflex. They can act centrally to suppress the respiratory cough center or locally to increase secretion and buffer irritation or to act as local anesthetics. These drugs should not be used longer than 1 week; patients with persistent cough after that time should seek medical evaluation. Decongestants are drugs that cause local vasoconstriction and, therefore, decrease the blood flow to the irritated and dilated capillaries of the mucous membranes lining the nasal passages and sinus cavities. An adverse effect that may accompany frequent or prolonged use of topical decongestants is rebound vasodilation, called rhinitis medicamentosa. The reflex reaction to vasoconstriction is a rebound vasodilation, which can lead to prolonged overuse of decongestants. Topical nasal decongestants are preferable in patients who need to avoid systemic adrenergic effects. Oral decongestants are associated with more systemic adrenergic effects and require caution in patients with CV disease, hyperthyroidism, or diabetes mellitus. Nasal steroid decongestants block the inflammatory response from occurring. These drugs, which take several days to weeks to reach complete effectiveness, are preferred therapy for patients with allergic rhinitis. The antihistamines selectively block the effects of histamine at the histamine-1 receptor sites, decreasing the allergic response. Antihistamines are used for the relief of symptoms associated with seasonal and perennial allergic rhinitis, allergic conjunctivitis, uncomplicated urticaria, or angioedema. Patients taking antihistamines may react to dryness of the skin and mucous membranes. The nurse should encourage them to drink plenty of fluids, use a humidifier, if possible, avoid smoke-filled rooms, and use good skin care and moisturizers. Some first-generation antihistamines should be avoided with any patient who has a prolonged QT interval because serious cardiac complications and even death have occurred. Expectorants are drugs that liquefy lower respiratory tract secretions. They are used for the symptomatic relief of respiratory conditions characterized by cough in conjunction with thick viscous mucus. Mucolytics work to break down mucus to aid high-risk respiratory patients in coughing up thick, tenacious secretions. Many of the drugs that act on the upper respiratory tract are found in various OTC cough and allergy preparations. Many of these preparations are a combination of medications. Patients need to be advised to always read the labels carefully to avoid inadvertent overdose and toxicity.