Drugs that Affect the

Respiratory System

P. Andrews

Chemeketa Community College

Paramedic Program

Sp08

When do we consider respiratory medications?

• Asthma– Decreases pulmonary function– May limit daily activity– Presents with

• SOB

• Wheezing

• coughing

Asthma, cont.

• Has two components!– Bronchoconstriction– Inflammation

• Usually an allergic reaction

Categories of respiratory

meds

• Bronchodilators• Beta2 specific agonists

(short-acting)• Beta2 specific agonists

(long-acting)• Methylxanthines

• Anticholinergics• Glucocorticoids• Leukotriene

antagonists• Mast-cell membrane

stabilizer

Advantages of Nebulized Meds.

• Smaller doses

• Onset Rapid

• Targeted delivery

• Less side effects

Disadvantages of Inhaled Meds

• Variables in delivery

• Usage variables– User– Caregiver

• Requires delivery to lungs– Not always adequate depth of resp.

Remember This?

• Absorption

• Distribution

• Metabolism

• Elimination

Absorption and Distribution

• Absorption– Ionized drugs (Ipratropium)

• absorb poorly• Won’t distribute well to body• Mostly local effect• Used for AEROSOL

– Non-Ionized drugs (Atropine)• Absorb well• Distribute well• Systemic Effect• Poor Aerosol Drug

Quick Review of Receptors

– Sympathetic• Adrenergic

– Nor-epinephrine» Primary neurotransmitter

– Parasympathetic• Cholinergic

– Acetylcholine» Primary neurotransmitter

Muscarinic

• A drug that stimulates Acetylcholine at PARASYMPATHETIC nerve endings.

• When drugs refer to muscarinic or antimuscarinic action,– It ONLY acts on Parasympathetic sites!

Adrenergic Stimulation

• Alpha 1– Vasoconstriction– Increase Blood Pressure

• Beta 1– Increase Heart Rate– Increase Force of Heartbeat

• Beta 2– Bronchial Smooth Muscle Contraction

Adrenergic Bronchodilators

• Indication– Obstructive Airway Disease

• Asthma, Bronchitis, Emphysema

• Mode of Action– Adrenergic Receptors

• Alpha 1…vasoconstriction

• Beta 1…Increase HR

• Beta 2…Bronchodilate (Yeah!)

Adrenergic Bronchodilators

• Adverse Effects– Dizziness, – Nausea, – Tolerance, – Hypokalemia, – Tremors– H/A

Adrenergic Bronchodilators• Nonspecific agonists

– Epinephrine (rarely used)

• Beta2 Specific agonists – Short acting

– Albuterol (Ventolin, Proventil)

– Metaproterenol (Alupent)

– Terbutaline (Brethine)

Bronchodilators, cont.

• Inhaled Beta2 selective (long-acting)

– Salmeterol (Serevent)

Anticholinergic Bronchodilators

• Indication– Bronchoconstriction– Mainly in COPD

• Mode of Action– Competes at Muscarinic receptors– Blocks Acetylcholine at smooth muscle– Reduces Mucus Production

Anticholinergic Bronchodilators

• Adverse Effects– Watch for Cholinergic side effects– More with nebulized form than MDI

• Examples– Atrovent (ipratropium) – Combivent (mixed w/ Albuterol)– Robinul

Mucus Controlling Agents

• Indication– Excessive , thick secretions– As in COPD and TB– (also used in treating acetaminophen OD)

• Action– Lower viscosity of mucus

Mucus Controlling Agents

• Side effects– Irritation of Airway– Bronchospasm– Pharyngitis, voice change, laryngitis– Chest pain– Rash

• Considerations– Have suction ready – Anticipate cough

Mucus Controlling Agents

• Examples– Mucomyst

• COPD, TB

– Pumozyme• Cystic Fibrosis

– Nebulized Saline• Simple yet effective!

Inhaled Corticosteroids

• Indications– Asthma– Anti-Inflammatory MAINTENANCE– Require Hours to Act! Preventative drug

• Mode of Action– Modifies RNA/DNA action in Cells– Complicated Stuff

Inhaled Corticosteroids

• Adverse Effect– Small incidence with nebulized

• Oral doses have high incidence

• Considerations– Not valuable in Acute Care– Watch for these in Pt Drug Lists

Corticosteroids

• Examples– Beclovent, Vanceril– Azmacort– Aerobid– Flovent– Pulmicort

Glucocorticoids

• Indications– Prophylactic treatment of Asthma

– Hayfever

• Mode of Action– Lowers release of Histamine in Mast Cells

– Lowers release of Inflammatory Response• Prevents Bronchospasm, airway inflammation

– Acts in allergic and Non-allergic Asthma

Glucocorticoids

– Not a bronchodilator!• Not for use in acute setting• Controllers, not relievers

• Adverse Effects– Include

• H/A• Nausea• Diarrhea

Glucocorticoid

– Cromolyn sodium• Similar to glucocorticoids

• S/E only coughing or wheezing

Anti-inflammatory Agents, cont.

• Glucocorticoids - Injected– Methyprednisolone (Solu-Medrol)– Dexamethasone (Decadron)

Nasal Decongestants

• Alpha1 agonist

– Phenylephrine– Pseudoephedrine– Phenylpropanolamine

• Administered as mist or drops

• S/E – rebound congestion (use greater than 7 days)

Antihistamines• Blocks histamine receptors• Common 1st generation – cause sedation

– Chlor-Trimeton– Benadryl– Phenergan

• Common 2nd generation – does not cause sedation– Seldane– Claritin– Allegra

• Caution: thickens bronchial secretions – do not use in Asthma!

Cough Suppressants

• Antitussive meds – suppress cough stimulus in CNS– Codeine, hydrocodone

A couple of ‘odd’ ones

Epinephrine Racemic Epinephrine

(microNEFRIN)• Class

– Bronchodilator (adrenergic agonist)

• Action– Affects both beta1 and beta2 receptors sites.

Bronchodilation, reduces subglottic edema– Also increases pulse rate and strength– Also Alpha, vasoconstriction, Increased BP

Epinephrine

• Indications– Croup, Epigottitis

• Bronchospasm

• Absorption – absorption occurs following inhalation

• Half-life– unknown

Epinephrine

• Contraindications– Hypersensitivity

• Precautions– Watch for Rebound Worsening– Watch ECG for changes– Increases Myocardial O2 demand

• Side effects– Nervousness, restlessness, tremor– arrhythmias, hypertension, tachycardia

Epinephrine

• Interactions– Beta blockers may negate effects

• Route and dosage– Inhalation

• One time Only

• 2.2% nebulized (may vary)

• Considerations– Give ENROUTE and

– only if patient in Extreme Distress

Status Asthmaticus

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