Respiratory DrugsDiseases of the Lower Respiratory Tract- COPDo Asthma (persistent and present most of the time despite treatment)o Emphysema – difficult to treat and maintain, patient will dieo Chronic bronchitisBronchial Asthma- Recurrent and reversible shortness of breath- Occurs when the airways of the lungs become narrow as a result of:o Bronchospasmso Inflammation of the bronchial mucosao Edema of the bronchial mucosao Production of viscous mucus- Alveolar ducts/alveoli remain open, but airflow to them is obstructed- Symptomso Wheezingo Difficulty breathingo The asthma patient that is having difficulty breathing does NOT always have wheezing Asthma- Four categorieso Intrinsic (occurring in patients with no history of allergies)o Extrinsic (occurring in patients exposed to a known allergen) o Exercise induced o Drug induced If having an asthma attack, treat with epinephrine - Status asthmaticuso Prolonged asthma attack that does not respond to typical drug therapy OR if no drug therapy is present o May last several minutes to hourso Medical emergencyChronic Bronchitis- 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 irritantsEmphysema- 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 impairedPharmacologic Overview- Bronchodilatorso These drugs relax bronchial smooth muscle, which causes dilation of the bronchi and bronchioles that are narrowed as a result of the disease processo Three classes: beta-adrenergic agonists, anticholinergics, and xanthine derivativesBronchodilators: Beta-Adrenergic Agonists- Short-acting beta agonist (SABA) inhalers o albuterol (Ventolin) o levalbuterol (Xopenex) – side effects are less- Long-acting beta agonist (LABA) inhalers o salmeterol (Serevent)- 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 systemo Sympathomimetics- One side effect is tremors - Three typeso Nonselective adrenergics Stimulate alpha, beta1 (cardiac), and beta2 (respiratory) receptors Example: epinephrine- Curative for emergencies o Nonselective beta-adrenergics Stimulate both beta1 and beta2 receptors Example: metaproterenol (Alupent)o Selective beta2 drugs Stimulate only beta2 receptors Example: albuterol (Proventil, others)- Mechanism of Actiono Begins at the specific receptor stimulatedo Ends with dilation of the airways Activation of beta2 receptors activates cyclic adenosine monophosphate (cAMP), whichrelaxes smooth muscle in the airway and results in bronchial dilation and increased airflow- Indicationso Relief of bronchospasm related to asthma, bronchitis, and other pulmonary diseaseso Used in treatment and prevention of acute attackso Used in hypotension and shocko Used to produce uterine relaxation to prevent premature labor- Adverse Effectso Alpha and beta (epinephrine) Insomnia, restlessness, anorexia, vascular headach, hyperglycemia, tremor, and cardiacstimulationo Beta1 and beta2 (metaproterenol) Cardiac stimulation, tremor, anginal pain, vascular headache, hypotensiono Beta2 (albuterol) Hypotension OR hypertension, vascular headache, and tremor- Nursing Implicationso Albuterol, if used too frequently, loses its beta2-specific actions at larger doseso As a result, beta1 receptors are stimulated, causing nausea, increased anxiety, palpitations, tremors, and increased heart rateo Ensure that patients take medications exactly as prescribed, with no omissions or double doseso Inform patients to report insomnia, jitteriness, restlessness, palpitations, chest pain, or any change in symptomsAnticholinergics- Ipratropium bromide (Atrovent) and tiotropium (Spiriva)- Slow and prolonged action- Used to prevent bronchoconstriction- NOT used for acute asthma exacerbations!o ALWAYS drying to a patient – complain of dry mouth - Mechanism of Actiono Acetylcholine (ACh) causes bronchial constriction and narrowing of the airwayso Anticholinergics bind to the ACh receptors, preventing ACh from bindingo Result: bronchoconstriction is prevented, airways dilate- Adverse Effectso Dry mouth or throat Non-pharmalogical interventions: chewing on gum, sucking on candy o Nasal congestiono Heart palpitationso Gastrointestinal distresso Headacheo Coughingo Anxiety – may have a little tremorXanthine Derivatives- Plant alkaloids: caffeine, theobromine, and theophylline- Only theophylline is used as a bronchodilator- Synthetic xanthines: aminophylline and dyphilline o Critical respiratory problems when the other medicines don’t work - Mechanism of Actiono Increase levels of energy-producing camp This is done by competitively inhibiting phosphodiesterase (PDE), the enzyme that breaks down cAMPo Result: decreased cAMP levels, smooth muscle relaxation, bronchodilation, and increased airflow- Drug Effectso Cause bronchodilation by relaxing smooth muscle in the airwayso Result: relief of bronchospasm and greater airflow into and out of the lungso Also cause CNS stimulationo 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)o Patient’s heart rate WILL increase- Indicationso Dilation of airways in asthmas, chronic bronchitis, and emphysemao Mild to moderate cases of acute asthmao Adjunct drug in the management of COPDo Not used as frequently because of potential for drug interactions and variables related to drug levels in the blood- Adverse Effectso Nausea, vomiting, anorexiao Gastroesophageal reflux during sleepo Sinus tachycardia, extrasystole, palpitations, ventricular dysrhythmiaso Transient increased urinationo Hyperglycemiao Weight loss from aneroxia - Nursing Implications: Xanthine Derivatives o Contraindications: history of PUD or GI disorderso Cautious use: cardiac diseaseo Timed-release preparations should not be crushed or chewed (cause gastric irritation)o Report to prescriber: Nausea, vomiting, restlessness, insomnia, irritability and tremorso Cigarette smoking enhances xanthine