View
216
Download
0
Embed Size (px)
Citation preview
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
•