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

1. Reversible small airway obstruction2. Progressive airway inflammation3. Increased airway responsiveness to variety of

stimuli4. = 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