WK 10 Pharm 2 PDF - LECTURE NOTES PDF

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Chapter 37: Respiratory Drugs Lower Respiratory Tract Diseases: Asthma • Persistent and present most of the time despite treatment • Recurrent and reversible shortness of breath • Occurs when the airways of the lungs become narrow as a result of: o Bronchospasms o Inflammation of the bronchial mucosa o Edema of the bronchial mucosa o Production of viscous mucus • Alveolar ducts/alveoli remain open, airflow to them is obstructed • Symptoms o Wheezing o Difficulty breathing • Four categories o Intrinsic- pt with no history of allergies o Extrinsic – pt exposed to known allergen o Exercise induced o Drug induced • Status asthmaticus o Prolonged asthma attack that does not respond to typical drug therapy o May last several minutes to hours o Medical emergency

~use two types short acting and long acting (understand that)

• Long term control drugs: o Leukotriene receptor antagonists o Mast cell stabilizers o Inhaled corticosteroids o Anticholinergic agents o Long-acting beta2 agonists (LABAs) o LABAs in combination with inhaled corticosteroids • Quick relief drugs o Intravenous systemic corticosteroids o Short-acting inhaled beta2 agonists (rescue agents)

Mechanisms of Anti-Asthma Drugs Antiasthmatic Anticholinergics

Leukotriene receptor antagonists

Beta agonists and xanthine derivatives

Corticosteroids Mast cell stabilizers (cromolyn and nedocromil)

Mechanism in Asthma Relief Block cholinergic receptors, thus preventing the binding of cholinergic substances that cause bronchoconstriction and increase secretions. Modify or inhibit the activity of leukotrienes, which decreases arachidonic acid–induced inflammation and allergen-induced bronchoconstriction. Raise intracellular levels of cyclic adenosine monophosphate, which in turn produces smooth muscle relaxation, and relaxes and dilates the constricted bronchi and bronchioles. Prevent the inflammation commonly provoked by the substances released from mast cells. Stabilize the cell membranes of the mast cells in which the antigenantibody reactions take place, thereby preventing the release of substances such as histamine that cause constriction.

Lower Respiratory Tract Diseases: Chronic Obstructive Pulmonary Disease (COPD) • Chronic bronchitis o Continuous inflammation and low-grade infection of the bronchi o Excessive secretion of mucus and certain pathologic changes in the bronchial structure o Often occurs as a result of prolonged exposure to bronchial irritants- cigarette smoke • Emphysema o Air spaces enlarge as a result of the destruction of alveolar walls

o The surface area where gas exchange takes place is reduced ▪ Dead space o Appears to be caused by the effect of proteolytic enzymes released from leukocytes in response to alveolar inflammation o Effective respiration is impaired o Barrel chest

Bronchodilators • Important part of the pharmacotherapy for all respiratory diseases. • Relax the bronchial smooth muscle → dilation of the bronchi and bronchioles that are narrowed as a result of the disease process • Three classes o Beta-adrenergic agonists o Anticholinergics

o Xanthine derivatives

Beta-Adrenergic Agonists: Short and Long-Acting Examples • Short-acting beta agonist (SABA) inhalers o albuterol – beta 2- lungs- airways- dilate o levalbuterol o pirbuterol o terbutaline o metaproterenol • Long-acting beta agonist (LABA) inhalers- longer onset NEVER use for acute treatment ~after being able to treat the urgency use these for maintenance o arformoterol o formoterol o salmeterol o indacterol o vilanterol in conjunction ▪ fluticasone (Breo Ellipta) ▪ umeclidinium (anticholinergic; Anoro Ellipta)

Beta-Adrenergic Agonists • Used during acute phase of asthmatic attacks • Quickly reduce airway constriction and restore normal airflow • Three Types o Nonselective adrenergic agonists ▪ Stimulate alpha, beta1 (cardiac), and beta2 (respiratory) receptors ▪ Example: epinephrine • Available as prefilled syringes for pts. with severe allergic reactions o EpiPen and Auvi-Q o Nonselective beta-adrenergics ▪ Stimulate both beta1 and beta2 receptors ▪ Example: metaproterenol o Selective beta2 drugs

▪ Stimulate only beta2 receptors ▪ Example: albuterol and levalbuterol ~monitor HR for short acting

Beta-Adrenergic Agonists: Mechanism of Action • Activation of beta2 receptors activates cyclic adenosine monophosphate (cAMP) → relaxes smooth muscle in the airway → bronchial dilation and increased airflow

Beta-Adrenergic Agonists Indications • Relief of bronchospasm related to asthma, bronchitis, and other pulmonary diseases • Used in treatment and prevention of acute attacks • Used in hypotension and shock Contraindications • Known drug allergy • Uncontrolled HTN • Cardiac dysrhythmias • High risk of stroke o Related to vasoconstrictive drug action

Beta-Adrenergic Agonists: Adverse Effects • Alpha and beta (epinephrine) o Insomnia o Restlessness o Anorexia o Vascular headache o Hyperglycemia- especially with EPI o Tremor- short term monitor o Cardiac stimulation!- increase HR and BP(monitor)! • Beta1 and beta2 (metaproterenol) o Cardiac stimulation o Tremor o Anginal pain o Vascular headache o Hypotension

• Beta2 (albuterol) o Hypotension or HTN o Vascular headache o Tremor

Beta-Adrenergic Agonists: Interactions • Diminished bronchodilation when nonselective beta blockers are used with the beta agonist bronchodilators • Monoamine oxidase inhibitors and Sympathomimetics o Avoided bc of enhanced risk for hypertension • Monitor patients with diabetes; an increase in blood glucose levels can occur.

Beta-Adrenergic Drug Profiles Albuterol • Short-acting beta2-specific bronchodilating beta agonist • Most used drug in this class • Must not be used too frequently→ dose related effects may be seen→ loses its beta2- specific actions in larger dosages→ stimulated beta 1→ causing nausea, increased anxiety, palpitations, tremors, and increase HR • Oral and inhalational use o Including metered-dose inhalers (MDIs) • Levalbuterol prescribed as an albuterol alternative for patients with certain risk factors (e.g., tachycardia, including tachycardia associated with albuterol treatment) Salmeterol • Long-acting beta2 agonist bronchodilator • Never to be used for acute treatment • Used for the maintenance treatment of asthma and COPD and in conjunction with an inhaled corticosteroid o Long acting do not use alone • Should never be given more than twice daily nor should the maximum daily dose (one puff twice daily) be exceeded • AE: immediate hypersensitivity reactions, headache, hypertension, and neuromuscular and skeletal pain.

Beta-Adrenergic Agonists: Nursing Implications • Albuterol, if used too frequently, loses its beta2-specific actions at larger doses → stimulates beta1 receptors → 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 o Especially with long acting- important to educate!

Anticholinergics • Used to prevent bronchoconstriction/bronchospasm associated with COPD • NOT used for acute exacerbations! • Examples o ipratropium o tiotropium o aclidinium • Contraindication: allergy to atropine

Anticholinergics: Mechanism of Action • Acetylcholine (ACh) causes bronchial constriction and narrowing of the airways → anticholinergics bind to the ACh receptors → prevents ACh from binding →airways dilate preventing bronchoconstriction • Indirectly cause airway relaxation and dilation • Help reduce secretions in COPD patients

Anticholinergics: Adverse Effects • Dry mouth or throat • Nasal congestion • Heart palpitations

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Gastrointestinal (GI) distress Urinary retention Increased intraocular pressure Headache Coughing Anxiety

Anticholinergics: Ipratropium • Oldest and most commonly used anticholinergic bronchodilator • Available both as a liquid aerosol for inhalation and as a multidose inhaler • Freq assessment, vital signs -HR, BP • Usually dosed twice daily • Others: similar drugs with longer durations of action o Tiotropium- once a day o Aclidinium- twice a day o umeclidinium- once a day • popular combo- albuterol and ipratropium

Xanthine Derivatives • Plant alkaloids o Caffeine, theobromine, and theophylline o Only theophylline and caffeine are used as a bronchodilator

• Synthetic xanthines o aminophylline and dypilline

Xanthine Derivatives: Mechanism of Action • Cause bronchodilation by increasing levels of energyproducing cAMP → inhibiting phosphodiesterase (PDE), the enzyme that breaks down cAMP → increase cAMP levels, smooth muscle relaxation, bronchodilation, and increased airflow • Drug Effects: Cause bronchodilation by relaxing smooth muscle in the airways → relief of bronchospasm and greater airflow into and out of the lungs o CNS stimulation o CV stimulation →positive inotropic effect, positive chronotropic effect →increased cardiac output and blood flow to the kidneys (diuretic effect)

Xanthine Derivatives: Indications Dilation of airways in asthmas or 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 • Slow onset of action

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Xanthine Derivative: Contraindications • • • • •

Drug known allergy Uncontrolled cardiac dysrhythmias 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 ~ overdose/ toxicity treatment with repeated administration of od activated charcoal

Xanthine Derivatives • Caffeine o Used without prescription as a CNS stimulant or analeptic to promote alertness (for long-duration driving or studying) o Cardiac stimulant in infants with bradycardia o Enhancement of respiratory drive-in infants • Theophylline o Most used xanthine derivative o Oral, rectal, injectable (as aminophylline), and topical dosage forms o Aminophylline: intravenous (IV) treatment of patients with status asthmaticus who have not responded to fast-acting beta agonists (epinephrine) o Therapeutic range for theophylline blood level is 10 to 20 mcg/mL (most clinicians now advise levels between 5 and 15 mcg/mL)

Xanthine Derivatives: Nursing Implications • Contraindications: history of PUD or GI disorders • Cautious use: cardiac disease • Timed-release preparations should not be crushed or chewed → causes gastric irritation • Report to prescriber: o Nausea o Vomiting o Restlessness o Insomnia o Irritability

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o Tremors Be aware of drug interactions with cimetidine, oral contraceptives, allopurinol, certain antibiotics, influenza vaccine o Increase therapeutic level → decrease med dose Cigarette smoking enhances xanthine metabolism o Levels the system to quick→ increase dose to maintain therapeutic level Food and beverage that contain caffeine (chocolate, coffee, cola, cocoa, tea) exacerbate CNS stimulation Interacting foods include charcoal-broiled, high-protein, and low-carbohydrate foods o May reduce serum levels of xanthines through various metabolic mechanisms Careful monitoring with older adults bc of increased risk for AE due to decrease drug metabolism

Leukotriene Receptor Antagonists (LTRAs) • Nonbronchodilating • Leukotriene is a substance that cause inflammation→ going to stop inflammation • Newer class of asthma medications • Currently available drugs o montelukast o zafirlukast o zileuton

Leukotrienes & LTRAs • Leukotrienes are substances released when a trigger, such as cat hair or dust, starts a series of chemical reactions in the body o Leukotrienes → inflammation, bronchoconstriction, and mucus production → coughing, wheezing, shortness of breath • LTRAs mechanism of action → prevent leukotrienes from attaching to receptors on cells in the lungs and circulation→ inflammation in lungs is blocked → relieving asthma symptoms

LRTAs: Drug Effects • By blocking leukotrienes: o Prevent smooth muscle contraction of the bronchial airways o Decrease mucus secretion o Prevent vascular permeability ▪ When we have inflammatory process we have increase permeability and fluid leaks out→ don’t want that o Decrease neutrophil and leukocyte infiltration to the lungs → preventing inflammation

LRTAs: Indications & Contraindications Indications • Prophylaxis and long-term treatment and prevention of asthma in adults and children 12 years and older • NOT meant for management of acute asthmatic attacks • Montelukast is approved for treatment of allergic rhinitis o Dosed once a day • Improvement with use is typically seen in 1 week Contraindications • Known drug allergy • Previous adverse drug reaction • Allergy to povidone, lactose, titanium dioxide, or cellulose derivatives o These are inactive ingredients in these drugs

LRTAs: Adverse Effects • zileuton o Headache, nausea, dizziness, insomnia • zafirlukast and montelukast o Headache, nausea, diarrhea

LRTAs: Nursing Implications • 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 o Educated pt. that just bc sees improvement in 2-3 days does not mean they can stop it yet • Advise patients to check with prescriber before taking over-thecounter (OTC) 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 • Emphasize that drugs are indicated for prevention, NOT treatment of acute asthmatic attacks. • Take montelukast at night

Corticosteroids (Glucocorticoids) Antiinflammatory properties Used for chronic asthma Do not relieve symptoms of acute asthmatic attacks Oral or inhaled forms o Inhaled forms reduce systemic effects • May take several weeks before full effects are seen • Most commonly used systemic corticosteroids for respiratory illness include prednisone (oral) and methylprednisolone (IV)

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Corticosteroids: Mechanism of Action • Stabilize membranes of cells that release harmful bronchoconstricting substances (leukocytes or white blood cells) • Increase responsiveness of bronchial smooth muscle to betaadrenergic stimulation • Dual effect of both reducing inflammation and enhancing the activity of beta agonists • Shown to restore in increase the responsiveness of bronchial smooth muscle to beta-adrenergic receptor stimulation →

more pronounced stimulation of beta2 receptors by beta agonist drugs (albuterol)

Inhaled Corticosteroids beclomethasone dipropionate budesonide ciclesonide flunisolide fluticasone o (vent)oral inhaler and (ase) nasal inhaler • mometasone • triamcinolone acetonide • • • • •

Corticosteroids: Indications • Treatment of bronchospastic disorders to control the inflammatory response that cause these disorders • Used for persistent asthma • Often used concurrently with beta-adrenergic agonists • Systemic corticosteroids are used only to treat acute exacerbations or severe asthma • IV corticosteroids: acute exacerbation of asthma or COPD • Not used for long periods of times

Corticosteroids: Contraindications Drug allergy Not intended as sole therapy for acute asthma attacks Hypersensitivity to glucocorticoids Patients whose sputum tests positive for Candida organisms o Immunocompromised pts. HIV, cancer • Patients with systemic fungal infection • • • •

Inhaled Corticosteroids: Adverse Effects • • • •

Pharyngeal irritation Coughing Dry mouth Oral fungal infections o Educate to rinse mouth!

o Clean nostrils- if nasal inhaler • Systemic effects are rare because low doses are used for inhalation therapy o High-doses IV or oral can affect any of the organ systems o Sysmtemic drug effects involve adrenocortical insufficiency, endocrine effects, CNS effects, dermatologic, and connective tissue effects • Adrenal suppression may occur when switching from systemic to inhaled o Need to reduce systemic gradually and not switch to quickly

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 • Cyclosporine and tacrolimus • Itraconazole • Phenytoin, phenobarbital, and rifampin

Inhaled Corticosteroids: Nursing Implications • Teach patients to gargle and rinse the mouth with lukewarm water afterward to prevent the development of oral fungal infections • 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 • 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

Phosphodiesterase-4 Inhibitor roflumilast • Indicated to prevent coughing and excess mucus from worsening and to decrease the frequency of life-threatening COPD exacerbations • NOT intended to treat bronchospasm • Adverse effects include nausea, diarrhea, headache, insomnia, dizziness, weight loss, and psychiatric symptoms • Not used freq. in hospital setting but physicians office

Monoclonial Antibody Antiasthmatic omalizumab, mepolizumab, reslizumab • Add-on therapy for treatment of asthma • Selectively binds to the immunoglobulin IgE, which in turn limits the release of mediators of the allergic response • Given by injection • Potential for producing anaphylaxis • Monitor closely for hypersensitivity reactions

o 4 hours after injection, respiratory- airway, vital signs

Nursing Implications: All Respiratory Drugs • Encourage patients to take measures that promote a generally good state of health to prevent, relieve, or decrease symptoms of COPD o Avoid exposure to conditions that precipitate bronchospasm (allergens, smoking, stress, air pollutants) o Adequate fluid intake o Compliance with medical treatment o Avoid excessive fatigue, heat, extremes in temperature, caffeine • 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 OTC medications • Perform a thorough assessment before beginning therapy, including: o Skin color o Baseline vital signs o Respirations (should be between 12 and 24 breaths/min) o Respiratory assessment, including pulse oximetry o Sputum production o Allergies o History of respiratory problems o Other medications o Smoking history • 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 • Monitor for therapeutic effects o Decreased dyspnea o Decreased wheezing, restlessness, and anxiety o Improved respiratory patterns with return to normal rate and quality o Improved activity tolerance

o Decreased symptoms and increased ease of breathing

Inhalers: Patient Education • Ensure that the patient can self-administer the medication o Provide demonstration and return demonstration o Ensure that the patient knows the correc...