Lower Respiratory Tract Drugs

COPD 

• Emphysema, chronic bronchitis

• Caused by chronic inflammation in respiratory tract due to exposure to irritants (tobacco smoke, environmental pollutants)

• Treatment: Limit exposure to irritants; increase PO fluid intake; breathing exercises; medications—same as asthma treatment

ASTHMA

• Reactive airway disorder—bronchospasm, difficulty breathing

• Mast cell overreactivity—histamine, cytokines, eosinophils released which causes airway edema, smooth muscle constriction, oversecretion of mucus

• Treatment: Avoidance of triggers; management of allergies; avoidance of drugs (ASA, NSAIDS, Beta blockers) that can worsen symptoms

ALPHA & BETA ADRENERGIC AGONISTS

• Albuterol (Proventil, Ventolin)
• Used for bronchodilation
• Stimulates Beta receptors
• Side effects: Beta 1 stimulation (tachycardia, nervousness)
• Terbutaline—similar drug (also used for preterm labor)
• Levobuterol (Xopenex)—similar to albuterol; fewer cardiac side effects; expensive
• Isoproterenol (Isuprel)—Beta 1 & Beta 2 stimulation
• Can be given by IV for severe asthma attacks

• Epinephrine (Adrenalin)
• Stimulates Alpha 1, Beta 1, Beta 2 receptors
• Produces bronchodilation
• Tachycardia, elevates blood pressure; risk of arrhythmias

ANTICHOLINERGICS

• Ipratropium (Atrovent)—Prototype drug
• Prevents bronchoconstriction (end result = bronchodilation)
• Side effects: decreased SLUDGE (dry mouth common)
• Use before inhaled steroid if using dual therapy
• Combination with albuterol=Combivent inhaler

METHYLXANTHINES

• Theophylline (Theo-Dur) & aminophylline—chemically related
• Similar to caffeine—side effects similar
• Narrow therapeutic window
• Not recommended in people with cardiac, renal, hepatic disease or seizures
• Long-acting; mostly used in maintenance of stable asthma

LEUKOTRIENE RECEPTOR ANTAGONISTS

• Montelukast (Singulair)—Prototype drug
• For maintenance/prophylactic therapy of asthma
• Administered by PO route; long-acting
• Decreases inflammatory response; decreases bronchoconstriction
• Few serious side effects; not indicated for acute asthmatic attacks

GLUCOCORTICOIDS (AKA STEROIDS)

• Indicated for acute exacerbations of COPD or asthma
• Action: Decreases inflammatory response
• Many side effects: Elevated blood glucose, increased risk of infection; high doses must be tapered over 1-2 weeks (risk of adrenal suppression); weight gain; fluid retention; osteoporosis & cataracts with long-term therapy
• Systemic effects less with inhaled corticosteroids
• Most common side effect with inhaled: thrush
• Prevent thrush by rinsing mouth after each use

CROMOLYN & NEDOCROMIL

• Cromolyn (Intal)—Prophylactic treatment of asthma
• Chronic therapy; available by PO route
• Inhibits release of histamine
• Side effects:  rebound bronchospasm if abruptly discontinued
• Commonly used in children with asthma

Upper Respiratory System Drugs

Upper Respiratory Disorders:
 Involves nasopharynx, pharynx, larynx, sinuses: Colds, rhinitis, sinusitis, pharyngitis

• ANTIHISTAMINES
• Block H1 and/or H2 receptors 
• Side effects: Decreased SLUDGE (anticholinergic), drowsiness
• Prototype drug: Diphenhydramine (Benadryl)—1st generation—PO, injectable (can be used for emergencies)
• 2nd generation antihistamines: Cetirizine (Zyrtec), fexofenadine (Allegra), loratidine (Claritin)—available only by PO

• DECONGESTANTS
• Alpha adrenergic effects
• Administered by nasal spray, PO
• Drugs: Ephedrine, pseudoephedrine (Sudaphed), phenylephrine (Neo-Synephrine), oxymetazoline (Afrin)—spray
• Side effects: Rebound congestion with overuse of spray; systemic: elevated BP, elevated blood glucose; dysrhythmias; avoid stimulants

• INTRANASAL GLUCOCORTICOIDS
• Systemic side effects rare; may cause nasal dryness
• Drugs: Fluticasone (Flonase), Triamcinolone (Nasacort)

• ANTITUSSIVES
• Suppress cough reflex
• Prototype drug: Dextromethorphan (Robitussin, Delsym)
• Available OTC
• Intoxication at high doses

• EXPECTORANTS
• Liquify sputum for easier production with coughing
• Need to increase PO fluid itake
• Drug: Guaifenesin (Robitussin, Mucinex)

Test 2 outline for respiratory meds

Bronchodilators:

• Anticholinergic: ipatropium(atrovent), itotropium(spiriva)
• first line unless contraindicated, dry mouth is the side effect
• Beta-2 agonist: albuterol, levalbuterol
• work faster than anticholinergic, best for emergencies, stimulate CNS is the side effects
• Methylxantines: Theodur, it also increases mucociliary action
• side effects: toxicity possible, n/v, seizures, insomnia

 Corticosteroids: decrease inflammation, increase sensitivity to cathecolamines

• Systemic: Prednisone, Hydrocortisone, Methylprednisolone
• Many side effects such as hyperglcemia,infection, tachycardia, easy bruising, weight gain
• Inhaled: fluticasone, beclamethasone
• for COPD maintenance, less side effects than systemic; rinse mouth after each use to prevent oral thrush

AntiHistamines:

• 1st generation: Benadryl; sedating, drowsiness, dry mouth
• 2nd generation: Claritin, Allegra; less sedating than 1st gen

Mucolytics: decrease thickness of mucous i.e Mucinex