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,

Diseases commonly treated with Bronchodilators

•Asthma

http://www.whatsasthma.org

COPD

Chronic Bronchitis

Emphysema

Review of Glossary Terms:
Lilley pg. 542

•Alveoli:

•Antigen:

•Antibody:

•Asthma Attack:

•Bronchial asthma:

•Chronic Bronchitis:

•Emphysema:

ADDITIONAL TERMS

•Acute:

•Exacerbation:

BRONCHODILATOR CLASSIFICATIONS

Bronchodilators:

ü Xanthines Derivatives

ü 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.

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

•Relieves 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

•Adjunct agent in COPD- relieves pulmonary edema and dyspnea in left sided heart failure

•Aminophylline used to increase urinary output-diuresis

Lab Diagnostics
Cavanaugh Text: pg. 215

Side and Adverse Effects

•Nausea

•Vomiting

•Anorexia

•Gastroesophageal reflux

CARDIAC!!!!!!!! HIGH ALERT!!!!

•Sinus Tachycardia

•Palpitations

•Ventricular Dysrhythmias

•Hyperglycemia

•Increased urinary output

Interactions

•Allopurinol

•Erythromycin

•Flu Vaccine

•Oral Contraceptives

•Need blood levels monitored closely

Available Theophylline Preparations

–Oral

–Parenteral

(aminophylline infusion)

–Rectal

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 THESE DRUGS USED?

•During acute phase of asthmatic attack

•To quickly reduce airway constriction

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) (Example: epinephrine)

•Nonselective beta-adrenergic: stimulate both beta1 and beta2 (Example: Isuprel)

•Selective beta2: stimulate the beta2 (Example: albuterol)

Drug Effects

**SELECTIVE BETA2

•Beta2 stimulationà causes bronchodilation; also a decreased diastolic B/P, decreased K+ level

NONSELECTIVE ADRENERGIC

•Alpha & Beta- constriction of arterioles, dilation skeletal muscle arterioles

Mechanism of Action

•Begins with specific receptors stimulated and ends with the dilation of airways

•cAMP is activated when beta2-adrenergic is stimulated

•Smooth muscles relax and airflow increased

•Alpha receptors causes vasoconstriction-limits secretions

Therapeutic Uses

•Pulmonary disorders for relief of bronchospasm

•Nonselective: Used for hypotension and shock treatment and to relieve nasal congestion and stuffiness

Side and Adverse Effects

•Insomnia

•Restlessness

•Anorexia

•Cardiac simulation

•Tremors

•Vascular headaches

•Hypotension

Interactions

•Beta-agonist with nonselective beta- adrenergic blockerà antagonizes the bronchodilation effect

•Avoid MAO inhibitors

•Diabetics may need adjustments

–Why would this be necessary?

–Which type of beta agonists???

–Nonselective adrenergics such as epinephrine

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???

THE END