Nursing 220: Pharmacology Module III: Respiratory Drugs

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Nursing 220 PharmacologyModule III Respiratory
Drugs

• Presented by
• Ronda M. Overdiek, MSN, CCRN, RNC

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Overview

• Review anatomy, physiology, pathophysiology of
  respiratory system.
• Chapter 71
• Chapter 72

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Respiratory Drugs

• Anti-inflammatory Agents
• Anti-asthmatic Agents
• Bronchodilating Agents
• Mucokinetic Agents
• Antirhinitis Agents
• Antitussive Agents
• Oxygen Therapy

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Bronchial Obstruction

• Makes breathing difficult
• Interferes with gas exchange
• Problem caused by
• Airway inflammation
• Bronchospasm
• Excessive mucous secretions

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Airway InflammationAnti-inflammatory Agents

• Airway inflammation caused by
• Chemical/physical irritants, allergy, infection
• Inflammation is hallmark of chronic bronchitis
• Corticosteroids
• Anti-inflammatory agents treat acute/chronic
  airway inflammation
• Aerosolized, Intravenous, oral dosing

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Airway InflammationAnti-inflammatory Agents

• Action (Inhaled)
• Act locally to suppress the inflammatory response
  to the lung
• Decrease both the release and effects of
  inflammatory mediators from injured tissues
• Stabilize capillary membranes, making them less
  prone to leakage.
• Potentiate bronchodilating agents by increasing
  beta receptor responsiveness to their effects
• Promote mucokinesis (mobilization of mucus) by
  improving mucociliary activity and by altering
  mucous gland function to increase the water
  content of airway secretions

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Airway InflammationAnti-inflammatory Agents

• Uses
• Asthma, chronic bronchitis, COPD, cystic
  fibrosis, etc.
• Examples (Inhaled)
• Beclomethasone (Vanceril, Beclovent)
• Triamcinolone Acetonide (Azmacort)
• Flunisolide (Aerobid, Nasalide)
• Examples (oral)
• Prednisone
• Prednisolone

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Anti-Asthmatic Agents

• Similar to inhaled steroids in that their
  function is to limit inflammation.
• Unlike inhaled corticosteroids, which decrease
  signs and symptoms of established inflammation,
  these agents prevent airway inflammation from
  occurring.
• Prototypes
• Cromolyn Sodium (Intal)
• Nedocromil Sodium (Tilade)

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Anti-Asthmatic Agents

• Action
• Alter mast cell membrane permeability to calcium
  ions, preventing mast cell degranulation by
  decreasing membranes sensitivity to irritants.
• Pharmacokinetics
• Effective only when administered by inhalation
• Locally acting agents that are absorbed by
  respiratory mucosa
• Not useful for aborting an ongoing attack
  (prophylaxis of asthma)

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Bronchodilating Agents

• Bronchospasm
• Abrupt narrowing of the airways
• Bronchodilators
• Administered to counteract bronchospasm
• Classifications
• Sympathomimetics
• Methylxanthines
• Anticholinergics

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Bronchodilating AgentsSympathomimetics

• Sympathomimetics
• Stimulate beta2 receptors to increase production
  of cyclic AMP which relaxes bronchial smooth
  muscle, reducing airway resistance and improving
  ariflow.
• Classified as either
• Catecholamines (Epinephrine)
• Affect both alpha and beta receptors, causing
  significant cardiovascular side effects
• Deactivated by first pass effects of the liverpo
  doses are ineffective
• Noncatecholamine (Albuterol)
• Beta2 stimulants are longer lasting evoke less
  side effects
• More resistant to liver degradation, effective as
  po doses

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Bronchodilating AgentsSympathomimetics

• Adverse Effects
• Stimulate the cardiovascular and CNS
• Cause tachycardia, palpitations, increased blood
  pressure, cause/aggravate dysrhythmias, extend an
  acute MI, anxiety, agitation, restlessness,
  insomnia, tremors.
• Noncatecholamine bronchodilators generally elicit
  fewer and less severe adverse effects than
  catecholamines.

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Bronchodilating AgentsMethylxanthines

• Methylxanthines
• CNS excitation (cardiac stimulation)
• Smooth muscle relaxants (bronchodilators)
• Vasodilation, diuresis
• Prototype Theophylline
• Bronchodilation
• Narrow therapeutic range (nausea, anxiety,
  palpitations, dysrhythmias, convulsions, death)
• P.O. form most frequently used, IV form in
  emergencies only (give slowlydeath can result
  w/rapid infusion)
• Aminophylline Each molecule of Amino dissociates
  to yield two molecules of theophylline
• Decrease the frequency and severity of asthma
  attacks

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Bronchodilating AgentsAnticholinergics

• Anticholinergics
• Decrease activity of the parasympathetic nervous
  system on bronchial smooth muscle
• Muscarinic antagonistpromotes bronchodilation
• Prototype Ipratroprium Bromide (Atrovent)
• Uses
• Controls bronchospasm in patients with chronic
  bronchitis, COPD, and selected cases of asthma
• Useful for patients who are unresponsive to other
  forms of treatment

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Mucokinetic Agents

• Mucolytics
• Agents that dissolves mucus
• Prototype Acetylcysteine (Mucomyst)
• Breaks strong disulfide bondsreplaces them with
  weaker bonds
• Expectorants
• Produce thinner secretions that are more easily
  expectorated by stimulating mucus glands to
  secrete thinner, less viscous mucus.
• Prototype
• Guaifenesin (Robitussin)
• Uses
• Chronic lung infections (cystic fibrosis,
  bronchiectasis)
• Caution Asthma patientspotential for generating
  allergy

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Using the Nursing Process

• Assessment
• Why is patient taking this drug?
• What other drugs is patient taking?
• Baseline s/s of respiratory distress, auscultate
  breath sounds, laboratory data (sputum culture,
  blood gases, pulmonary function tests).
• Assess own knowledge of drug

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Using the Nursing Process

• Nursing Diagnosis
• Ineffective airway clearance
• Impaired gas exchange
• Ineffective breathing pattern
• Planning
• Patient specific, based on nursing diagnosis

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Using the Nursing Process

• Intervention (Administration)
• Seven Rights
• Aerosol delivery methods
• Patient teaching
• Evaluation
• Was the outcome what you planned?
• Change in physical exam
• Evaluate for toxicity

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Question 1

• Mr. Keenes, a 33-year-old patient with asthma,
  complains of anxiety and shakiness, nausea, and
  palpitations after taking his TheoDur (an
  extended-release theophylline preparation).
  Which of the following actions is LEAST
  appropriate for the nurse to take?
• Check the appropriateness of Mr. Keeness dosage
• Ask the physician to authorize a check of her
  serum theophylline level
• Reassure Mr. Keenes that these effects are normal
  and that they will disappear after a few doses
• Review the importance of swallowing (not chewing)
  extended-release products

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Question 2

• When evaluating the effectiveness of expectorant
  therapy, the nurse will anticipate the following
  outcome
• Wheezing will be absent from all lung fields
• Respiratory rate and depth will increase
• Blood gases will be within normal limits
• Sputum clearance is increased

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Antirhinitis Agents

• Rhinitis inflammation of the nasal passages
  caused by allergies, infections, chemical, or
  physical irritants.
• Antihistamines
• Help relieve symptoms of rhinitis caused by
  allergy
• Decongestants
• Provide relief for nonallergic rhinitis

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Antirhinitis Agents

• Antihistamines
• Agents that compete with histamine for space on
  histaminic receptors
• Do NOT inhibit the release of histamine
• DO antagonize most of the effects
• Decrease capillary permeability
• Reverse vasodilation present at the site of
  inflammation
• Uses
• Allergic rhinitis (hay fever), sinusitis,
  conjunctivitis
• Treat motion sickness, sedatives
• Vital reversal of anaphylactic shock
• Examples
• Diphenhydramine (Benadryl), terfenadine
  (Seldane), loratadine (Claritin), cetirizine
  hydrochloride (Zyrtec), fexofenadine (Allegra).

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Decongestants

• Decongestants
• Stimulate alpha-adrenergic receptors in the nasal
  arterioles, restricting blood flow, further
  reducing leakage of fluid from capillaries into
  tissues, decreasing pressure on lymph vessels
  which facilitates lymph drainage removing
  accumulated fluid from the tissues.
• Use
• Treat stuffiness and post nasal drip associated
  with the common cold, fu, or nonallergic
  sinusitis.

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Antitussive Agents

• Antitussive Agents
• Decrease the intensity and frequency of coughing
  episodes
• Suppress the cough centers stimulation
  threshold, making it less responsive to incoming
  impulses from the irritant receptors.
• Examples
• Codeine, hydrocodone, benzonatate (Tessalon
  Perles), dextromethorphan (Robitussin DM)

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Oxygen Therapy

• Oxygen
• Provides tissues with sufficient oxygen
• Uses
• Patients with decreased cardiac output, reduced
  blood-oxygen carrying capacity, or decreased
  partial pressure of oxygen in arterial blood,
  patients w/increased oxygen demands.

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Question

• The patient who requires narcotic antitussive
  therapy to control a cough should be instructed
• To limit fluid intake
• To take a decongestant preparation along with the
  antitussive
• To avoid alcohol while on this therapy
• To avoid caffeinated beverages

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Questions?