Respiratory Drugs

1. Mucolytic Drugs
Drugs Affecting the Mucomyst (acetylecysteine)
MOA: Decreases viscosity of mucous by
Respiratory System breaking specific bonds in the mucous
molecule. Blocks formation of toxic
metabolites in Acetaminophen overdose.
Uses: Relief of abnormal viscous mucous
that decrease airflow and gas exchange
Review A&P and Know key terms (inhalation).
Prevention of hepatotoxicity due to
acetaminophen overdose (PO).
Mucomyst Expectorants
Adverse Effects: Anorexia, N&V – smells like Example: Robitussin (guaifenesin)
rotten eggs. Bronchospasm. MOA:
Nursing Measures: Warn about smell. Reduces adhesiveness and decreases
Instruct to report N&V, dyspnea. Wash surface tension of mucous making it easier to
nebulizer after use – causes a sticky coating. be expectorated.
Be sure patient coughs and clears airway Uses: Expectorant
prior to administering. Be sure patient is able
to clear airway after dose or use suction. Nursing Measures: Instruct to take each
dose with glass of water and increase intake
of water.
Decongestants Antitussives
Examples: Neosynepherine, Afrin, (nasal Examples: Codeine (central acting narcotic)
sprays. Sudafed (PO). Tessalon (local anesthesia of stretch
MOA: Reduce congestion and edema by receptors in lungs) Swallow whole.
constricting arterioles to reduce blood flow to MOA: Suppress cough by depression of the
nasal mucosa.
cough center in the medulla or the cough
Uses: Rhinitis associated with respiratory receptors in the throat, trachea or lungs.
infections and allergies.
Contraindications: Hypertension, heart Contraindicated in supportive lung disease
disease, glaucoma. where pus that needs to be expectorated.
Caution re: rebound congestion with sprays. Uses: Dry cough that interferes with sleep.
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2. Antihistamines Antihistamines
Block action of histamine by occupying Uses: Allergic rhinitis, rash and pruitus in
H1receptors, the same receptors as anaphylaxis.
histamine. They prevent edema, itching and Adverse Effects: 1st generation – sedation,
bronchoconstriction associated with the anticholinergic effects. 2nd generation – less
action of histamine. sedation.
Examples: 1st generation: Benadryl Contraindications: glaucoma, pregnancy,
urinary obstruction.
(diphenhydramine) (prototype), Tavist
(clemastine) 2nd generation: Claritin Nursing Measures: Teach to avoid alcohol
and other CNS depressants. D/C 72 hr.
(loratadine), Allerga (fexofenadine)
prior to allergy testing.
Bronchodilator & Antiasthma Drugs Proventil (albuterol)
Adernergic bronchodilators MOA: Short acting beta 2-adernergic agonist relaxes
Examples: Epinephrine (SC or inhaled) bronchial smooth muscles to relieve bronchospasms
and reduce airway resistance.
MOA: Stimulates beta 2 receptors to relax
Uses: Acute asthma attacks (reliever) – inhalation
bronchospasms, constricts bronchial
onset in 5 – 10 min.
arterioles and blocks histamine to reduce
congestion and edema and increase tidal Adverse Effects: tremors, nausea, palpatations.
volume and vital capacity. Nursing Measures: Teach the short acting beta2
agonits lose their brochodilating effects with
Most all OTC asthma inhalers contain
overuse. Teach how to use inhaler.
epinephrine.
Uses: Asthma, anaphylaxis, cardiac arrest.
Serevent (salmeterol) Anticholinergic Bronchodilators
MOA: Long acting beta 2 agonist acts to Example: Atrovent (ipratropium)
relax bronchospasms and reduce airway MOA: When given by inhalation, anticholinergics
resistance. block the action of acetylcholine in bronchial smooth
muscles and reduces intracellular GMP, a
Uses: Prophylaxis (controller) of acute bronchoconstrictor.
bronchoconstriction. Slower onset up to 20 Uses: Emphysema, chronic bronchitis, COPD, acts
min., duration 12 hours or more. synergistically with beta 2 agonists to improve lung
function up to 15% in asthma.
Adverse Effects: Cough, nervousness, N, HA,
dizziness.
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3. Xanthine Bronchodilators Antiinflammatory Asthma Drugs
Examples: Short acting - Aminophylline Leukotrine modifiers:
(theophylline), Long acting – Theo-Dur
Example: Singular (montelukast)
MOA: Directly relax bronchial smooth muscles.
Stimulate the respiratory center which strengthens MOA: Occupy receptors to prevent leukotrien
diaphragmatic contractions and prevents fatigue in from acting on tissues and causing
COPD. bronchoconstriction and mucous production.
Uses: Asthma uncontrolled by other drugs, COPD. Uses: Prophylaxis and chronic treatment of
Adverse Effects: tachycardia, N,V,D,GI bleed, asthma. (controller). May decrease need for
restlessness.
beta 2 agonists.
Nursing Measures: Check levels (5-15 mcg/ml.)
Adverse Effects: HA, N, infection.
Corticosteroids Corticosteroids
Examples: Prednisone (PO) Azmacort Uses: Acute, severe asthma given IV, PO if
(triamcinolone), Pulmocort (budesonide), repeated inhalations are not effective.
Flovent (fluticasone) Chronic asthma (inhalers), COPD.
MOA: Suppress inflammation by inhibiting Adverse Effects: GI bleeding, edema.
movement of fluids and protein into tissues,
migration and function of neutrophils and May be given for 7-10 days for acute attacks.
eosinophils, synthesis of histamine in mast Taper if over a week.
cells, and production of inflammatory sub.
such as prostaglandins, interleukins,
leukotrienes. They also increase the number
(4 hr) and sensitivity (2 hr) of beta2 receptors.
Mast Cell Stablilzers
Examples: Fivent (cromolyn) and Tilade (nedocromil)
MOA: Antiinflammatory effect by inhibiting release of
histamine and other mediators of inflammation. No
effect on bronchodilation.
Uses: Prophylaxis of acute asthma attacks. Not
used much since leukotrine modifiers available.
Adverse Effects: Generally well tolerated.
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