chapter 37 respiratory drugs copyright © 2014 by mosby, an imprint of elsevier inc

Chapter 37

Respiratory Drugs

Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Diseases of the Lower Respiratory Tract

COPD Asthma (persistent and present most of the time

despite treatment) Emphysema Chronic bronchitis

Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 2

Recurrent and reversible shortness of breath Occurs when the airways of the lungs become

narrow as a result of: Bronchospasms Inflammation of the bronchial mucosa Edema of the bronchial mucosa Production of viscous mucus

Bronchial Asthma


Alveolar ducts/alveoli remain open, but airflow to them is obstructed

Symptoms Wheezing Difficulty breathing

Bronchial Asthma (cont’d)


Four categories Intrinsic (occurring in patients with no history of

allergies) Extrinsic (occurring in patients exposed to a known

allergen) Exercise induced Drug induced

Asthma


Status asthmaticus Prolonged asthma attack that does not respond to

typical drug therapy May last several minutes to hours Medical emergency

Asthma (cont’d)


Continuous inflammation and low-grade infection of the bronchi

Excessive secretion of mucus and certain pathologic changes in the bronchial structure

Often occurs as a result of prolonged exposure to bronchial irritants

Chronic Bronchitis


Air spaces enlarge as a result of the destruction of alveolar walls

Caused by the effect of proteolytic enzymes released from leukocytes in response to alveolar inflammation

The surface area where gas exchange takes place is reduced

Effective respiration is impaired

Emphysema


Bronchodilators These drugs relax bronchial smooth muscle, which

causes dilation of the bronchi and bronchioles that are narrowed as a result of the disease process

Three classes: beta-adrenergic agonists, anticholinergics, and xanthine derivatives

Pharmacologic Overview


Short-acting beta agonist (SABA) inhalers albuterol (Ventolin) levalbuterol (Xopenex) pirbuterol (Maxair) terbutaline (Brethine) metaproterenol (Alupent)

Long-acting beta agonist (LABA) inhalers arformoterol (Brovana) formoterol (Foradil, Perforomist) salmeterol (Serevent)

Bronchodilators: Beta-Adrenergic Agonists


Used during acute phase of asthmatic attacks Quickly reduce airway constriction and restore

normal airflow Agonists, or stimulators, of the adrenergic

receptors in the sympathetic nervous system Sympathomimetics

Bronchodilators: Beta-Adrenergic Agonists


Three typesNonselective adrenergics

Stimulate alpha, beta1 (cardiac), and beta2 (respiratory) receptors

Example: epinephrineNonselective beta-adrenergics

Stimulate both beta1 and beta2 receptors

Example: metaproterenol (Alupent)

Bronchodilators: Beta-Adrenergic Agonists (cont’d)


Three types (cont’d)Selective beta2 drugs

Stimulate only beta2 receptors

Example: albuterol (Proventil, others)

Bronchodilators: Beta-Adrenergic Agonists (cont’d)


Begins at the specific receptor stimulated Ends with dilation of the airways

Activation of beta2 receptors activates cyclic adenosine monophosphate (cAMP), which relaxes smooth muscle in the airway and results in bronchial dilation and increased airflow

Beta-Adrenergic Agonists: Mechanism of Action


Relief of bronchospasm related to asthma, bronchitis, and other pulmonary diseases

Used in treatment and prevention of acute attacks

Used in hypotension and shock Used to produce uterine relaxation to prevent

premature labor

Beta-Adrenergic Agonists: Indications


Alpha and beta (epinephrine) Insomnia Restlessness Anorexia Vascular headache Hyperglycemia Tremor Cardiac stimulation

Beta-Adrenergic Agonists: Adverse Effects


Beta1 and beta2 (metaproterenol) Cardiac stimulation Tremor Anginal pain Vascular headache Hypotension

Beta-Adrenergic Agonists: Adverse Effects (cont’d)


Beta2 (albuterol) Hypotension OR hypertension Vascular headache Tremor

Beta-Adrenergic Agonists: Adverse Effects (cont’d)


Ipratropium bromide (Atrovent) and tiotropium (Spiriva)

Slow and prolonged action Used to prevent bronchoconstriction NOT used for acute asthma exacerbations!

Anticholinergics


Acetylcholine (ACh) causes bronchial constriction and narrowing of the airways

Anticholinergics bind to the ACh receptors, preventing ACh from binding

Result: bronchoconstriction is prevented, airways dilate

Anticholinergics: Mechanism of Action


Dry mouth or throat Nasal congestion Heart palpitations Gastrointestinal distress Headache Coughing Anxiety

Anticholinergics: Adverse Effects


Plant alkaloids: caffeine, theobromine, and theophylline

Only theophylline is used as a bronchodilator Synthetic xanthines: aminophylline and

dyphilline

Xanthine Derivatives


Increase levels of energy-producing cAMP This is done by competitively inhibiting

phosphodiesterase (PDE), the enzyme that breaks down cAMP

Result: decreased cAMP levels, smooth muscle relaxation, bronchodilation, and increased airflow

Xanthine Derivatives: Mechanism of Action


Cause bronchodilation by relaxing smooth muscle in the airways

Result: relief of bronchospasm and greater airflow into and out of the lungs

Also cause CNS stimulation

Xanthine Derivatives: Drug Effects


Also cause cardiovascular stimulation: increased force of contraction and increased heart rate, resulting in increased cardiac output and increased blood flow to the kidneys (diuretic effect)

Xanthine Derivatives: Drug Effects (cont’d)


Dilation of airways in asthmas, chronic bronchitis, and emphysema

Mild to moderate cases of acute asthma Adjunct drug in the management of COPD Not used as frequently because of potential for

drug interactions and variables related to drug levels in the blood

Xanthine Derivatives: Indications


Nausea, vomiting, anorexia Gastroesophageal reflux during sleep Sinus tachycardia, extrasystole, palpitations,

ventricular dysrhythmias Transient increased urination Hyperglycemia

Xanthine Derivatives: Adverse Effects


Nonbronchodilating Newer class of asthma medications Currently available drugs

montelukast (Singulair) zafirlukast (Accolate) zileuton (Zyflo)

Leukotriene Receptor Antagonists (LTRAs)


Leukotrienes are substances released when a trigger, such as cat hair or dust, starts a series of chemical reactions in the body

Leukotrienes cause inflammation, bronchoconstriction, and mucus production

Result: coughing, wheezing, shortnessof breath

LTRAs: Mechanism of Action


LRTAs prevent leukotrienes from attaching to receptors on cells in the lungs and in circulation

Inflammation in the lungs is blocked, and asthma symptoms are relieved

LTRAs: Mechanism of Action (cont’d)


By blocking leukotrienes: Prevent smooth muscle contraction of the

bronchial airways Decrease mucus secretion Prevent vascular permeability Decrease neutrophil and leukocyte infiltration

to the lungs, preventing inflammation

LTRAs:Drug Effects


Prophylaxis and long-term treatment and prevention of asthma in adults and children 12 years of age and older

NOT meant for management of acute asthmatic attacks

Montelukast is also approved for treatment of allergic rhinitis

LTRAs: Indications


zileuton Headache, nausea, dizziness, insomnia, liver function

zafirlukast Headache, nausea, diarrhea, liver function

LTRAs: Adverse Effects


Antiinflammatory properties Used for chronic asthma Do not relieve symptoms of acute

asthmatic attacks Oral or inhaled forms

Inhaled forms reduce systemic effects May take several weeks before full

effects are seen

Corticosteroids


Stabilize membranes of cells that release harmful bronchoconstricting substances These cells are called leukocytes, or white

blood cells Increase responsiveness of bronchial smooth

muscle to beta-adrenergic stimulation

Corticosteroids: Mechanism of Action


beclomethasone dipropionate (Beclovent)

budesonide (Pulmicort Turbuhaler) dexamethasone sodium phosphate (Decadron

Phosphate Respihaler) flunisolide (AeroBid) fluticasone (Flonase) triamcinolone acetonide (Azmacort) ciclesonide (Omnaris)

Inhaled Corticosteroids


Persistent asthma Often used concurrently with beta-adrenergic agonists

Inhaled Corticosteroids: Indications


Pharyngeal irritation Coughing Dry mouth Oral fungal infections Systemic effects are rare because low doses are

used for inhalation therapy

Inhaled Corticosteroids: Adverse Effects


roflumilast (Daliresp) Indicated to prevent coughing and excess mucus from

worsening and to decrease the frequency of life-threatening COPD exacerbations

Adverse effects include nausea, diarrhea, headache, insomnia, dizziness, weight loss, and psychiatric symptoms

Phosphodiesterase-4 Inhibitor


omalizumab (Xolair) Selectively binds to the immunoglobulin IgE, which in

turn limits the release of mediators of the allergic response

Omalizumab is given by injection Potential for producing anaphylaxis Monitor closely for hypersensitivity reactions

Monoclonial Antibody Antiasthmatic


Encourage patients to take measures that promote a generally good state of health so as to prevent, relieve, or decrease symptoms of COPD Avoid exposure to conditions that precipitate

bronchospasm (allergens, smoking, stress, air pollutants)

Adequate fluid intake Compliance with medical treatment Avoid excessive fatigue, heat, extremes in

temperature, caffeine

Nursing Implications


Encourage patients to get prompt treatment for flu or other illnesses, and to get vaccinated against pneumonia or flu

Encourage patients to always check with their physician before taking any other medication, including over-the-counter medications

Nursing Implications (cont’d)


Perform a thorough assessment before beginning therapy, including: Skin color Baseline vital signs Respirations (should be between 12 and 24

breaths/min) Respiratory assessment, including pulse oximetry Sputum production Allergies History of respiratory problems Other medications



Teach patients to take bronchodilators exactly as prescribed

Ensure that patients know how to use inhalers and MDIs, and have patients demonstrate use of the devices

Monitor for adverse effects



Classroom Response Question

Which medication will the nurse teach a patient with asthma to use when experiencing an acute asthma attack?

A.albuterol (Ventolin)

B.salmeterol (Serevent)

C.theophylline (Theo-Dur)

D.montelukast (Singulair)


Monitor for therapeutic effects Decreased dyspnea Decreased wheezing, restlessness, and anxiety Improved respiratory patterns with return to normal

rate and quality Improved activity tolerance Decreased symptoms and increased ease of

breathing



Albuterol, if used too frequently, loses its beta2-specific actions at larger doses

As a result, beta1 receptors are stimulated, causing nausea, increased anxiety, palpitations, tremors, and increased heart rate

Nursing Implications: Beta-Adrenergic Agonists


Ensure that patients take medications exactly as prescribed, with no omissions or double doses

Inform patients to report insomnia, jitteriness, restlessness, palpitations, chest pain, or any change in symptoms

Nursing Implications: Beta-Adrenergic Agonists (cont’d)



A patient with chronic bronchitis calls the office for a refill of his albuterol inhaler. He just had the prescription filled 2 weeks ago, but he says it is empty. When asked, he tells the nurse, “I use it whenever I need it, but now when I use it I feel so sick. I’ve been needing to use it more often.” What is the most appropriate action by the nurse?A.The nurse should confirm the pharmacy location for the needed refill.

B.The nurse should ask the patient to come to the office for an evaluation of his respiratory status.

C.The nurse should tell the patient not to use this drug too often.

D.The nurse should consult the prescriber for a different inhaler prescription.


Contraindications: history of PUD or GI disorders

Cautious use: cardiac disease Timed-release preparations should not be

crushed or chewed (cause gastric irritation)

Nursing Implications: Xanthine Derivatives


Report to prescriber: Nausea Vomiting Restlessness Insomnia Irritability Tremors

Nursing Implications: Xanthine Derivatives (cont’d)


Be aware of drug interactions with cimetidine, oral contraceptives, allopurinol, certain antibiotics, influenza vaccine, others

Cigarette smoking enhances xanthine metabolism

Interacting foods include charcoal-broiled, high-protein, and low-carbohydrate foods These foods may reduce serum levels of xanthines

through various metabolic mechanisms

Nursing Implications: Xanthine Derivatives (cont’d)


Ensure that the drug is being used for chronic management of asthma, not acute asthma

Teach the patient the purpose of the therapy Improvement should be seen in about

1 week

Nursing Implications: LTRAs


Advise patients to check with prescriber before taking over-the-counter or prescribed medications to determine drug interactions

Assess liver function before beginning therapy and throughout

Teach patient to take medications every night on a continuous schedule, even if symptoms improve

Nursing Implications: LTRAs (cont’d)


Teach patients to gargle and rinse the mouth with lukewarm water afterward to prevent the development of oral fungal infections

If a beta-agonist bronchodilator and corticosteroid inhaler are both ordered, the bronchodilator should be used several minutes before the corticosteroid to provide bronchodilation before administration of the corticosteroid

Nursing Implications: Inhaled Corticosteroids


Teach patients to monitor disease with a peak flow meter

Encourage use of a spacer device to ensure successful inhalations

Teach patient how to keep inhalers and nebulizer equipment clean after uses

Nursing Implications: Inhaled Corticosteroids (cont’d)


For any inhaler prescribed, ensure that the patient is able to self-administer the medication Provide demonstration and return demonstration Ensure that the patient knows the correct time

intervals for inhalers Provide a spacer if the patient has difficulty

coordinating breathing with inhaler activation Ensure that the patient knows how to keep track of

the number of doses in the inhaler device

Inhalers: Patient Education



A patient is prescribed two different types of inhaled medications for treatment of chronic obstructive pulmonary disease (COPD). After administering the first medication, how long should the nurse wait to administer the second medication?

A.One minute

B.Five minutes

C.Ten minutes

D.Fifteen minutesCopyright © 2014 by Mosby, an imprint of Elsevier Inc. 59

Case Study

The nurse is providing teaching to a group of individuals with chronic obstructive pulmonary disease (COPD) at a community center. Which statement by one of the attendees indicates that further teaching is needed?A.“If I develop a puffy face, I will stop taking methylprednisolone (Medrol) immediately.”B. “I will inform my prescriber of any weight gain of 2 pounds or more in 24 hours or 5 pounds or more in 1 week.”C.“I use omalizumab (Xolair) to control my asthma but not for an acute asthma attack.”D.“When taking theophylline (Theo-Dur), I will advise my prescriber if I experience epigastric pain.”


Case Study

One of the attendees expresses concern regarding her granddaughter’s asthma. The attendee tells the nurse that she is afraid that she will not know which of her granddaughter's medications to give first in case of an asthma attack. Which medication should the nurse inform the attendee to administer first for an acute asthma attack?A. ipratropium (Atrovent) B. albuterol (Proventil)C. budesonide (Pulmicort Turbuhaler)D. montelukast (Singulair)


Case Study

One of the attendees tells the nurse that he has asthma and is being treated with a short-acting inhaled beta2 agonist. The nurse identifies this treatment as which step of the stepwise therapy for the treatment of asthma?A. Step 1 B. Step 2C. Step 3D. Step 4


chapter 37 respiratory drugs copyright © 2014 by mosby, an imprint of elsevier inc

Documents

imprint of elsevier

respiratory drugs copyright

impaired emphysema copyright

bronchial structure

bronchial mucosa edema

bronchial smooth muscle

alveolar inflammation

respiratory receptors