Drugs that Affect the Respiratory System P. Andrews Chemeketa Community College Paramedic Program...
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Transcript of Drugs that Affect the Respiratory System P. Andrews Chemeketa Community College Paramedic Program...
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
•