chapter 38 respiratory drugs - week 4 Flashcards

Question

Xanthine Derivatives:  Mechanism of Action

Answer 1

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

Answer 2

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)

Answer 3

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

Answer 4

Known drug allergy Uncontrolled cardiac dysthymias Seizure disorders Hyperthyroidism Peptic ulcers

Answer 5

Nausea, vomiting, anorexia Gastroesophageal reflux during sleep Sinus tachycardia, extrasystole, palpitations, ventricular dysrhythmias Transient increased urination Hyperglycemia

Answer 6

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)

Answer 7

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.

Answer 8

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

Answer 9

Nonbronchodilating Newer class of asthma medications Currently available drugs montelukast (Singulair®) zafirlukast (Accolate®)

Answer 10

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.

Answer 11

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

Answer 12

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

Answer 13

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

Answer 14

Both drugs (montelukast, zafirlukast) may lead to liver dysfunction. zafirlukast Headache, nausea, diarrhea

Answer 15

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

Answer 16

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.

Answer 17

beclomethasone dipropionate (Qvar®) budesonide (Pulmicort Turbuhaler®) fluticasone furoate (Avamys®) fluticasone propionate (Flovent Dickus®) ciclesonide (Omnaris®)

Answer 18

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

Answer 19

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

Answer 20

Pharyngeal irritation Coughing Dry mouth Oral fungal infections Systemic effects are rare because low doses are used for inhalation therapy.

Answer 21

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)

Answer 22

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).

Answer 23

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.

Answer 24

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.

Answer 25

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

Answer 26

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.

Answer 27

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.

Answer 28

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.

Answer 29

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.

Answer 30

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.