Bronchodilators Lilley Pharmacology Text: Chapter 35 Original PPT modified by: Anita A. Kovalsky, R.N., M.N.Ed. Professor of Nursing Original by: Professor Edwards,

Review of Glossary Terms: Lilley pg. 542 Alveoli: Antigen: Antibody: Asthma Attack: Bronchial Asthma: Chronic Bronchitis: Emphysema: ADDITIONAL TERMS Acute: Exacerbation:

Diseases commonly treated with Bronchodilators Asthma http://www.whatsasthma.org COPD Chronic Bronchitis Emphysema

BRONCHODILATOR CLASSIFICATIONS Bronchodilators: Xanthines Derivatives Beta-Agonists

Xanthine Derivatives (Refer to Prototype List in syllabus, pg. 19) Prototype Drugs: Theophylline- Theo-dur Aminophylline

How Do These Drugs Work? Relieve Bronchoconstriction Cause bronchodilatation

Mechanism of Action Cause bronchodilation by: Increasing the levels of the energy producing substance called cAMP Inhibiting PDE the enzyme that breaks down *cAMP…. Subsequently, this causes smooth muscle relaxation and broncchodilation; also inhibits release of chemical mediators such as histamine, etc. *cAMP = cyclic adenosine monophosphate

Mechanism of Action contd. Slow onset of action, so used more as preventative measure, however, also used as a continuous IV infusion to treat reversible bronchospasm in COPD clients who have an exacerbation of symptoms

Drug Effects Relieve bronchopasms by causing airways to dilate, thereby improving air passage into and out of lungs Stimulates CNS: Increases contractility of heart (+ inotropic) Increases heart rate (+chrontropic) Increases cardiac output, thereby causing a…. Diuretic effect…what would cause this???????

Therapeutic Uses Dilate airways in asthma, chronic bronchitis and emphysema Adjunctive agent for treatment of pulmonary edema and dyspnea in left-sided heart failure by increasing cardiac output and increasing bloodflow to kidneys diuresis

Lab Diagnostics Cavanaugh Text: pg. 215 Aminophylline/Theophylline Levels: 10-18ug/ml WNL (within normal limits) >20ug/ml TOXIC LEVEL

Side and Adverse Effects Nausea Vomiting Anorexia Gastroesophageal reflux CARDIAC!!!!!!!! HIGH ALERT!!!! Sinus Tachycardia Palpitations Ventricular Dysrhythmias Hyperglycemia (transient) Increased urinary output (transient)

Interactions Allopurinol Cimetidine Erythromycin Flu Vaccine Oral Contraceptives Need blood levels monitored closely

Available Theophylline Preparations Oral Parenteral (aminophylline infusion) Rectal

Prototype Drugs: (Brand name in parentheses) Beta-Agonists or Sympathomimetic Bronchodilators (Refer to Prototype List in syllabus, pg. 19 Also listed in Lilley, pg. 548) Prototype Drugs: (Brand name in parentheses) - Albuterol (Proventil) Beta2 Selective OTHERS: -Ephedrine -Epinephrine (Adrenalin, Primatene, Bronkaid) -Terbutaline (Brethine)

When are Beta-Agonists used? During acute phase of asthmatic attack To quickly reduce airway constriction and cause bronchodilation WHY ARE THEY CALLED AGONISTS???? AGONISTS or stimulators of SNS receptors-----> SYMPATHOMIMETIC ACTION WHAT IS THE PRIMARY MECHANISM OF ACTION?? Imitate the effects of norepinephrine on receptors Stimulate beta2-adrenergic receptors in the lungs causing dilation within the airways of the lungs (Example: Albuterol/Proventil)

Specific Receptors Refer to Lilley text, pg. 547 Nonselective adrenergic: stimulate the alpha, beta1 (cardiac), and beta2- (respiratory) receptors (Example: epinephrine) Nonselective beta-adrenergic: stimulate both beta1 and beta2 receptors (Example: Isuprel) Selective beta2: stimulate the beta2 receptors (Example: albuterol)

Drug Effects **SELECTIVE BETA2 Beta2 stimulation causes bronchodilation; also a decreased diastolic B/P, decreased K+ level

Mechanism of Action Begins with specific receptors stimulated and ends with the dilation of airways cAMP is activated when a beta2-adrenergic receptor is stimulated Smooth muscles relax and airflow increased

Therapeutic Uses of Beta-Agonists Pulmonary disorders for relief of bronchospasm Nonselective: Used for hypotension and shock treatment and to relieve nasal congestion and stuffiness

Bronchodilators: Beta-Agonists Side Effects Alpha-Beta Beta1 and Beta2 Beta2 (epinephrine) (isoproterenol) (albuterol) Insomnia cardiac stimulation hypotension restlessness tremor vascular headache anorexia anginal pain cardiac stimulation vascular headache tremor vascular headache

Interactions Beta-agonist with nonselective beta-adrenergic blocker (beta-blocker) antagonizes the bronchodilation effect!!! Avoid MAO inhibitors

Available Selected Beta-Agonist Preparations PO SC Inhaler Nebulizer IM

Nursing Considerations for Bronchodilators Does the client have cardiac disease?? If so, which type of bronchodilator should be the drug of choice?? Does the client have diabetes?? If the client is receiving a xanthine, what blood levels should be monitored???

A client is receiving IV aminophylline for a severe exacerbation of COPD. Which of the following would you expect when evaluating for a therapeutic response to the medication? A. Drowsiness B. Increased heart rate C. Dilatation of bronchioles D. Increased respiratory rate

Which of the following side effects is associated with the use of xanthine derivatives? A. Bradycardia B. Palpitations C. Increase in appetite D. Constriction of bronchioles

Overview of Drugs Affecting the Respiratory System Bronchodilators Xanthine derivatives Beta-agonists Anticholinergics Antileukotriene agents Corticosteroids Mast cell stabilizers

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