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) Beta 2 Specific agonists – Short acting –Albuterol (Ventolin, Proventil) –Metaproterenol (Alupent) –Terbutaline (Brethine)

Bronchodilators, cont. Inhaled Beta 2 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 Alpha 1 agonist –Phenylephrine –Pseudoephedrine –Phenylpropanolamine Administered as mist or drops S/E – rebound congestion (use greater than 7 days)

Antihistamines Blocks histamine receptors Common 1 st generation – cause sedation –Chlor-Trimeton –Benadryl –Phenergan Common 2 nd 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 beta 1 and beta 2 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 O 2 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