Respiratory Drugs Diseases of the Lower Respiratory Tract COPD o Asthma persistent and present most of the time despite treatment o Emphysema difficult to treat and maintain patient will die o Chronic bronchitis Bronchial Asthma 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 but airflow to them is obstructed Symptoms o Wheezing o Difficulty breathing o The asthma patient that is having difficulty breathing does NOT always have wheezing Asthma Four categories o 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 asthmaticus o Prolonged asthma attack that does not respond to typical drug therapy OR if no drug therapy is present o May last several minutes to hours o Medical emergency Chronic 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 irritants Emphysema 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 impaired Pharmacologic Overview Bronchodilators o These drugs relax bronchial smooth muscle which causes dilation of the bronchi and bronchioles that are narrowed as a result of the disease process o Three classes beta adrenergic agonists anticholinergics and xanthine derivatives Bronchodilators 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 system o Sympathomimetics One side effect is tremors Three types o 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 Action o Begins at the specific receptor stimulated o Ends with dilation of the airways Activation of beta2 receptors activates cyclic adenosine monophosphate cAMP which relaxes smooth muscle in the airway and results in bronchial dilation and increased airflow Indications o Relief of bronchospasm related to asthma bronchitis and other pulmonary diseases o Used in treatment and prevention of acute attacks o Used in hypotension and shock o Used to produce uterine relaxation to prevent premature labor Adverse Effects o Alpha and beta epinephrine Insomnia restlessness anorexia vascular headach hyperglycemia tremor and cardiac stimulation o Beta1 and beta2 metaproterenol Cardiac stimulation tremor anginal pain vascular headache hypotension o Beta2 albuterol Hypotension OR hypertension vascular headache and tremor Nursing Implications o Albuterol if used too frequently loses its beta2 specific actions at larger doses o As a result beta1 receptors are stimulated causing nausea increased anxiety palpitations tremors and increased heart rate o Ensure that patients take medications exactly as prescribed with no omissions or double doses o Inform patients to report insomnia jitteriness restlessness palpitations chest pain or any change in symptoms Anticholinergics 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 Action o Acetylcholine ACh causes bronchial constriction and narrowing of the airways o Anticholinergics bind to the ACh receptors preventing ACh from binding o Result bronchoconstriction is prevented airways dilate Adverse Effects o Dry mouth or throat Non pharmalogical interventions chewing on gum sucking on candy o Nasal congestion o Heart palpitations o Gastrointestinal distress o Headache o Coughing o Anxiety may have a little tremor Xanthine 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 Action o Increase levels of energy producing camp This is done by competitively inhibiting phosphodiesterase PDE the enzyme that breaks down cAMP o Result decreased cAMP levels smooth muscle relaxation bronchodilation and increased airflow Drug Effects o Cause bronchodilation by relaxing smooth muscle in the airways o Result relief of bronchospasm and greater airflow into and out of the lungs o Also cause CNS stimulation o 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 Indications o Dilation of airways in asthmas chronic bronchitis and emphysema o Mild to moderate cases of acute asthma o Adjunct drug in the management of COPD o Not used as frequently because of potential for drug interactions and variables related to drug levels in the blood Adverse Effects o Nausea vomiting anorexia o Gastroesophageal reflux during sleep o Sinus tachycardia extrasystole palpitations ventricular dysrhythmias o Transient increased urination o Hyperglycemia o Weight loss from aneroxia Nursing Implications Xanthine Derivatives o Contraindications history of PUD or GI disorders o Cautious use cardiac disease o Timed release preparations should not be crushed or chewed cause gastric irritation o Report to prescriber Nausea vomiting restlessness insomnia irritability and tremors o Cigarette smoking enhances xanthine metabolism o Interacting foods include charcoal broiled high protein and low carbohydrate foods These foods may reduce serum levels of xanthines through various