Transcript Drugs that Affect the Respiratory System

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.
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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?
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Absorption
Distribution
Metabolism
Elimination
Absorption and
Distribution
• Absorption
– Ionized drugs (Ipratropium)
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absorb poorly
Won’t distribute well to body
Mostly local effect
Used for AEROSOL
– Non-Ionized drugs (Atropine)
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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
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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
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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
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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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