Chapter 9 Respiratory Drugs

Terms to Define Asthma Bronchospasm Status Asthmaticus Metered dose inhaler (MDI) Spacer Nebulizer Bronchodilator

Asthma Inflammatory disease in which inflammation causes the airways to tighten Reversible condition Intermittent attacks are precipitated by specific triggering events Causes a decrease in the amount of oxygen and carbon dioxide exchanged

Asthma An asthmatic lung compared to a normal lung More sensitive Responds to lower doses of allergens Studies strongly support genetic predisposition to developing asthma

Characteristics of Asthma Reversible small airway obstruction Progressive airway inflammation Increased airway responsiveness to variety of stimuli = wheezing, dyspnea, acute & chronic cough

Asthma Attack: First Response Triggered by an antigen-antibody reaction Causes degranulation of mast cells which release histamine Result: bronchospasm and increased mucus production that plugs the small airways

Asthma Attack: Second Response Bronchoconstriction with delayed, sustained reactions Causes self-sustaining inflammation

Asthmatic Response

Devices Used in Asthma Therapy Metered dose inhaler (MDI) Contains medication and compressed air Delivers specific amount of medication with each puff Spacer Used with MDIs to get medication into lungs instead of depositing on back of throat

Nebulizers Uses stream of air that flows through liquid medication to make a fine mist for inhalation Very effective Must be cleaned and taken care of to reduce risk of contamination Used for young children

Short-Acting Inhaled Bronchodilators albuterol Relaxes bronchial smooth muscle with little effect on heart rate, duration of 3 to 6 hours

ProAir/Albuterol (Bronchodilator) Works by widening the airways in the lungs Indicated usage: Tx or prevent breathing problems in patients with Asthma Prevent breathing problems with exercise

Proventil/Albuterol (Bronchodilator) bronchodilator that relaxes muscles in the airways and increases air flow to the lungs Exercise induced bronchospasm Prevent bronchospasm in people with reversible obstructive airway disease

Ventolin/Albuterol (Bronchodilator) a bronchodilator that relaxes muscles in the airways and increases air flow to the lungs Indicated usage Prevent bronchospasm for people with reversible obstructive airway disease Prevent exercise induced bronchospasm

Dispensing Issues of albuterol Proventil HFA and ProAir HFA cannot be interchanged If Rx for an albuterol inhaler, any of the 3 brands can be used

Asthma Agents: Leukotriene Inhibitors Leukotrienes Increase edema, mucus, and vascular permeability Substances can pass through blood vessels 100 to 1,000 times more potent than histamine Block synthesis of, or the body’s inflammatory responses to, leukotrienes

Montelukast/Singulair (Leukotriene Inhibitor) Indicated for prophylaxis and chronic treatment of asthma Do not use to treat acute attacks Approved for use in adults and children 12 months and older Once-daily dosage Also used to treat seasonal allergies

Asthma Agents: Corticosteroids Anti-inflammatory agents that suppress the immune response Used for more difficult cases of asthma Usually prescribed on alternate-day basis or as tapering doses when short-term therapy is indicated Many patients with asthma still not using

Primary Side Effects of Corticosteroids Oral candidiasis Irritation and burning of nasal mucosa Hoarseness Dry mouth

Side Effects of Long-Time Use of Oral Corticosteroids Growth of facial hair in females Breast development in males “Buffalo hump,” “moon face” Edema Weight gain Easy bruising

Corticosteroids Always use lowest effective dose Add salmeterol to inhaled corticosteroids if needed to decrease the dose of corticosteroid needed for control

Dispensing Issues of Corticosteroids Patient should rinse mouth with water after using inhalers to prevent oral candidiasis Patient should be taught how to correctly use these medications

fluticasone (Flonase, Flovent) Corticosteroid Flonase (Flovent) is same drug in nasal spray Flonase Flovent comes in 3 strengths Lowest for mild asthma Highest to wean patients off oral corticosteroids 1 to 2 weeks to reach maximum benefit

fluticasone-salmeterol (Advair Diskus) Combines corticosteroid (anti-inflammatory) and a beta-2 agonist Indicated for maintenance therapy in patients 12 years and older Available in powder for inhalation Should not be used with a spacer

Nasal Corticosteroids Most effective monotherapy for allergic rhinitis Must be used daily Can cause nasal irritation and bleeding; direct spray away from septum Local infections of Candida albicans may occur in nose with long term use

mometasone furoate (Nasonex) (nasal corticosteroids) Depresses release of endogenous chemical mediators of inflammation Reverses dilation and permeability of vessels in area Children over 12 can use to prevent symptoms of allergic rhinitis

Methylprednisolone/Medrol Steroid- prevents the release of substances in the body that cause inflammation Tx- allergic disorders

Promethazine/Phenergan (antihistamine) Blocks effects of histamine (which triggers inflammatory response) Treat allergy symptoms

Fexofenadine/Allegra (Antihistamine) Blocks the effect of histamine in the body Tx allergy symptoms