chapter 38 respiratory drugs - week 4 Flashcards
diseases of the lower respirotary tract
Chronic obstructive pulmonary disease
Asthma (persistent and present most of the time despite treatment)
Formerly known as emphysema and chronic bronchitis
bronchial asthma
- 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
- The alveolar ducts and alveoli remain open, but airflow to them is obstructed
Symptoms
Wheezing
Difficulty breathing
asthma
A sudden and dramatic onset is referred to as an asthma attack.
Prolonged asthma attack that does not respond to typical drug therapy is known as status asthmaticus.
staus asthmaticus
Prolonged asthma attack that does not respond to typical drug therapy
May last several minutes to hours
Medical emergency
copd (chronic obstrictive pulmonary disease)
Progressive respiratory disorder
Characterized by chronic airflow limitation, systematic manifestations, and significant comorbidities
chronic bronchitis`
Presence of cough and sputum for at least 3 months in each of 2 consecutive years
Separate disease from chronic obstructive pulmonary disease
broncho dilators
Bronchodilators
* Relax bronchial smooth muscle, which causes dilation of the bronchi and bronchioles that are narrowed as a result of the disease process
* Three classes: β-adrenergic agonists, anticholinergics, and xanthine derivatives
Short-acting ß-agonist (SABA) inhalers
salbutamol (Ventolin®)
Terbutaline sulphate (Bricanyl®)
Long-acting ß-agonist (LABA) inhalers
formoterol (Foradil®, Oxeze®)
salmeterol (Serevent®)
Long-acting ß-agonist and glucocorticoid steroid combination inhaler
budesonide/formoterol fumarate dihydrate (Symbicort®)
Use as a reliever or rescue treatment for moderate to severe asthma when symptoms worsen
bronchodilators: ß-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
ß-Adrenergic Agonists: Mechanism of Action
Begins at the specific receptor stimulated
Ends with dilation of the airways
Activation of ß2-receptors activates cyclic adenosine monophosphate, which relaxes smooth muscle in the airway and results in bronchial dilation and increased airflow.
ß-Adrenergic Agonists: Indications
Relief of bronchospasm related to asthma, chronic obstructive pulmonary disease (COPD), and other pulmonary diseases
Used in treatment and prevention of acute attacks
Used in hypotension and shock
ß-Adrenergic Agonists: Contraindications
Known drug allergy
Uncontrolled cardiac dysrhythmias
High risk of stroke (because of the vasoconstrictive drug action)
ß-Adrenergic Agonists: Adverse Effects
α and ß (epinephrine)
Insomnia
Restlessness
Anorexia
Vascular headache
Hyperglycemia
Tremor
Cardiac stimulation
ß1 and ß2
Cardiac stimulation, tachycardia
Tremor
Anginal pain
Vascular headache
ß2 (salbutamol)
Hypotension or hypertension
Vascular headache
Tremor
ß-Adrenergic Agonists: Interactions
Diminished bronchodilation when nonselective ß-blockers are used with the ß-agonist bronchodilators
Monoamine oxidase inhibitors
Sympathomimetics
Monitor patients with diabetes; an increase in blood glucose levels can occur.
ß-Adrenergic Agonists: Salbutamol Sulphate (Ventolin®)
Short-acting ß2-specific bronchodilating ß-agonist
Most commonly used drug in this class
Must not be used too frequently
Oral, parenteral, and inhalational use
Inhalational dosage forms include metered-dose inhalers as well as solutions for inhalation (aerosol nebulizers).
ß-Adrenergic Agonists: Salmeterol (Serevent®)
Long-acting ß2-agonist bronchodilator
Never to be used alone but in combination with an inhaled glucocorticoid steroid
Used for the maintenance treatment of asthma and COPD; salmeterol maximum daily dose (one puff twice daily) should not be exceeded.
Anticholinergics: Mechanism of Action
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
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
ipratropium (Atrovent®), tiotropium bromide monohydrate (Spiriva®)
Indirectly cause airway relaxation and dilation
Help reduce secretions in COPD patients
Indications: prevention of the bronchospasm associated with COPD; not for the management of acute symptoms
Anticholinergics: Adverse Effects
Dry mouth or throat
Nasal congestion
Heart palpitations
Gastrointestinal distress
Urinary retention
Increased intraocular pressure
Headache
Coughing
Anxiety
Anticholinergics: Ipratropium Bromide
Oldest and most commonly used anticholinergic bronchodilator
Available both as a liquid aerosol for inhalation and as a multidose inhaler
Usually dosed twice daily
Xanthine Derivatives
Plant alkaloids: caffeine, theobromine, and theophylline
Only theophylline and caffeine are currently used clinically.
Synthetic xanthines: aminophylline
Xanthine Derivatives: Mechanism of Action
Increase levels of energy-producing cyclic adenosine monophosphate (cAMP)
This is done by competitively inhibiting phosphodiesterase, the enzyme that breaks down cAMP.
Result: decreased cAMP levels, smooth muscle relaxation, bronchodilation, and increased airflow
Xanthine Derivatives: Drug Effects
Cause bronchodilation by relaxing smooth muscle in the airways
Result: relief of bronchospasm and greater airflow into and out of the lungs
Also cause central nervous system stimulation
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: Indications
Dilation of airways in asthmas and COPD
Mild to moderate cases of acute asthma
Not for management of acute asthma attack
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: Contraindications
Known drug allergy
Uncontrolled cardiac dysthymias
Seizure disorders
Hyperthyroidism
Peptic ulcers
Xanthine Derivatives: Adverse Effects
Nausea, vomiting, anorexia
Gastroesophageal reflux during sleep
Sinus tachycardia, extrasystole, palpitations, ventricular dysrhythmias
Transient increased urination
Hyperglycemia
Xanthine Derivatives: Caffeine
Used without prescription as a central nervous system stimulant or analeptic to promote alertness (e.g., for long-duration driving or studying)
Cardiac stimulant in infants with bradycardia
Enhancement of respiratory drive in infants in Neonatal Intensive Care Units (NICUs)
Xanthine Derivatives: Theophylline
Most commonly used xanthine derivative
Oral and injectable (as aminophylline) dosage forms
Aminophylline: intravenous (IV) treatment of patients with status asthmaticus who have not responded to fast-acting ß-agonists such as epinephrine
Therapeutic range for theophylline blood level is 55 to 100 mmol/L.
Canadian Asthma Consensus guideline recommends levels between 28 to 55 mmol/L.
Nonbronchodilating Respiratory Drugs
Leukotriene receptor antagonists (montelukast, zafirlukast)
Corticosteroids (beclomethasone, budesonide, dexamethasone, flunisolide, fluticasone, ciclesonide, and triamcinolone)
Mast cell stabilizers: rarely used and no longer included in Canadian Asthma Management Continuum
Leukotriene Receptor Antagonists
Nonbronchodilating
Newer class of asthma medications
Currently available drugs
montelukast (Singulair®)
zafirlukast (Accolate®)
Leukotriene Receptor Antagonists: Mechanism of Action (1 of 2)
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, shortness
of breath
Leukotriene receptor antagonists 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.
Leukotriene Receptor Antagonists: Drug Effects
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
Leukotriene Receptor Antagonists: Indications
Prophylaxis and long-term treatment and prevention of asthma in adults and children
Montelukast safe in children 2 years of age and older
Zafirlukast safe in children 12 years of age and older
Not meant for management of acute asthmatic attacks
Montelukast is also approved for treatment of allergic rhinitis
Improvement with their use is typically seen in about 1 week
Leukotriene Receptor Antagonists: Contraindications
Known drug allergy
Previous adverse drug reaction
Allergy to povidone, lactose, titanium dioxide, or cellulose derivatives—important to note because these are inactive ingredients in these drugs
Leukotriene Receptor Antagonists: Adverse Effects
Both drugs (montelukast, zafirlukast) may lead to liver dysfunction.
zafirlukast
Headache, nausea, diarrhea
Corticosteroids (Glucocorticoids)
Anti-inflammatory properties
Used in treatment of pulmonary diseases
May be administered intravenously
Oral or inhaled forms
Inhaled forms reduce systemic effects.
May take several weeks before full
effects are seen
Corticosteroids: Mechanism of Action
Stabilize membranes of cells that release harmful bronchoconstricting substances
These cells are called leukocytes (white
blood cells).
Increase responsiveness of bronchial smooth muscle to ß-adrenergic stimulation
Dual effect of both reducing inflammation and enhancing the activity of ß-agonists
Corticosteroids have also been shown to restore or increase the responsiveness of bronchial smooth muscle to ß-adrenergic receptor stimulation, which results in more pronounced stimulation of the ß2-receptors by ß-agonist drugs such as salbutamol.
Inhaled Corticosteroids
beclomethasone dipropionate (Qvar®)
budesonide (Pulmicort Turbuhaler®)
fluticasone furoate (Avamys®)
fluticasone propionate (Flovent Dickus®)
ciclesonide (Omnaris®)
Inhaled Corticosteroids: Indications
Primary treatment of bronchospastic disorders to control the inflammatory responses that are believed to be the cause of these disorders
Persistent asthma
Often used concurrently with the ß-adrenergic agonists
Systemic corticosteroids are generally used only to treat acute exacerbations or severe asthma.
IV corticosteroids: acute exacerbation of asthma or other COPD
Inhaled Corticosteroids: Contraindications
Drug allergy
Not intended as sole therapy for acute asthma attacks
Hypersensitivity to glucocorticoids
Patients whose sputum tests are positive for Candida organisms
Patients with systemic fungal infection
Inhaled Corticosteroids: Adverse Effects
Pharyngeal irritation
Coughing
Dry mouth
Oral fungal infections
Systemic effects are rare because low doses are used for inhalation therapy.
Inhaled Corticosteroids: Drug Interactions
Drug interactions are more likely to occur with systemic (versus inhaled) corticosteroids.
May increase serum glucose levels, possibly requiring adjustments in dosages of antidiabetic drugs
May raise the blood levels of the immunosuppressants cyclosporine and tacrolimus; itraconazole may reduce clearance of the steroids
phenytoin, phenobarbital, and rifampin
Greater risk of hypokalemia with concurrent diuretic use (e.g., furosemide, hydrochlorothiazide)
Phosphodiesterase Type 4 Inhibitor
roflumilast (Daxas®)
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 (anxiety and depression).
Monoclonal Antibody Antiasthmatic
omalizumab (Xolair®)
Selectively binds to immunoglobulin E, 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.
Nursing Implications bronchodilators
Encourage patients to take measures that promote a generally good state of health so as to prevent, relieve, or decrease symptoms of COPD.
Avoiding exposure to conditions that precipitate bronchospasm (allergens, smoking, stress, air pollutants).
Maintaining an adequate fluid intake
Complying with medical treatment
Avoiding excessive fatigue, heat, extremes in temperature, and caffeine.
Teach patients to take bronchodilators exactly as prescribed.
Ensure that patients know how to use inhalers and metered-dose inhalers, and have patients demonstrate the use of the devices.
Monitor for adverse effects.
nursing assessment bronchodilators
Perform a thorough assessment before beginning therapy, including:
Skin colour
Baseline vital signs
Respirations (should be between 12 and 20 breaths/min)
Respiratory assessment, including pulse oximetry
Sputum production
Allergies
History of respiratory problems
Other medications
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
Nursing Implications: ß-Adrenergic Agonists
Salbutamol, if used too frequently, loses its ß2-specific actions at larger doses.
As a result, ß1-receptors are stimulated, causing nausea, increased anxiety, palpitations, tremors, and increased heart rate.
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: Xanthine Derivatives (1 of 3)
Contraindications: history of peptic ulcer disease or gastrointestinal disorders
Cautious use: cardiac disease
Timed-release preparations should not be crushed or chewed (causes gastric irritation).
Report to prescriber
Nausea
Vomiting
Restlessness
Insomnia
Irritability
Tremors
Be aware of drug interactions with cimetidine, oral contraceptives, allopurinol, certain antibiotics, influenza vaccine, and 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: Leukotriene Receptor Antagonists
Ensure that the medication is being used for long-term management of asthma, not acute asthma.
Teach the patient the purpose of the therapy.
Improvement should be seen in about 1 week.
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 therapy.
Teach patients to take medications every night on a continuous schedule, even if symptoms improve.
Nursing Implications: Inhaled Corticosteroids
Teach patients to gargle and rinse the mouth with lukewarm water afterward to prevent the development of oral fungal infections.
If a ß-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.
Teach patients to monitor disease with a peak flow meter.
Encourage the use of a spacer device to ensure successful inhalations.
Teach the patient how to keep inhalers and nebulizer equipment clean after use.
inhaler patient education
For any inhaler prescribed, ensure that the patient is able to self-administer the medication.
Provide a demonstration and a 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.
