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Flashcards in Asthma & COPD Deck (43)
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drugs useful for treating asthma

1. B2 –agonists (albuterol, terbutaline, pirbuterol, levalbuterol, metaproterenol, bitolterol, formoterol, salmeterol)
2. Corticosteroids (beclomethasone, triamcinolone, flunisolide, fluticasone, budesonide, mometasone)
3. Cromolyn and Nedocromil
4. Muscarinic antagonists: ipratropium and tiotropium
5. Theophylline
6. Leukotriene antagonists (zafirlukast, montelukast, zileuton)
7. Omalizumab


B2 agonists drugs

short-acting (SABA): albuterol, levalbuterol, terbutaline, pirbuterol, bitolterol, metaproterenol
long-acting (LABA): salmeterol, formoterol


B2 agonists use

SABAs are the drugs of choice for mild asthma; these drugs have no anti-inflammatory effects and should never be used as the sole therapy for patients with chronic asthma; they are used for symptomatic relief from asthma but long-term 2 agonist use is controversial


B2 agonists moa

directly relax bronchial smooth muscle by acting on 2 receptors in the lungs; stimulation of this receptor activates adenylyl cyclase and increases cAMP, which in turn activates PKA which phosphorylates the MLCK and causes muscle relaxation; stabilizes mast cell membranes


B2 agonists kinetics

the short-acting agents have a rapid onset of action (5-15 min. inhaled, 15-30 min. oral) and provide relief for 4-6 hours; LABAs have a slower onset of action (about 1 hour) but provides relief for at least 12 hours; LABAs are not used for acute asthmatic attacks; given usually as metered-dose inhalers (MDI) and also by nebulizer; these drugs are not catecholamines so are not destroyed by catechol-O-methyl-transferase (COMT)


B2 agonists adverse

as selective 2 –agonists given in the form of inhalers, these drugs have few adverse effects; excessive doses can cause skeletal muscle tremor and cardiac stimulation; unnecessary use has been associated with the increase in asthma mortality


The use of orally administered 2 –agonists ...

has not gained wide acceptance due to the risk of systemic side effects such as muscle cramps, cardiac tachyarrhythmias, and metabolic disturbances; there are two situations where oral 2 –agonists are used frequently: in young children (<5 years old) who cannot manipulate a metered dose inhaler oral therapy with albuterol or metaproterenol syrups are well tolerated and effective, and second, oral therapy is effective in patients who experience irritation or enhanced cough or bronchospasms when using the inhaler



Inhaled: beclomethasone, triamcinolone, flunisolide, fluticasone, budesonide, mometasone
Systemic: methylprednisolone, prednisolone, prednisone



moderate to severe asthma; asthmatic patients who require inhaled 2 -agonists four or more times weekly are reviewed as candidates for inhaled corticosteroids; severe asthmatics may require systemic glucocorticoids for a short term



act on cytoplasmic glucocorticoid receptors and stimulate protein synthesis (4-12 hours before clinical response is seen); are anti-inflammatory; to be effective in controlling inflammation, these drugs must be taken continuously; these steroids have no direct effect on the airway smooth muscle; three main benefits from corticosteroids are 1) inhibition of inflammation at all levels, 2) reducing mucous production and hypersecretion, 3) increasing 2 receptor levels



a. the development of inhaled steroids have greatly reduced the need for systemic corticosteroid treatment;a large fraction (80-90%) of the inhaled dose is deposited in the mouth and pharynx, or is swallowed, and these steroids are absorbed from the gut and enter the systemic circulation through the liver
b. most inhaled corticosteroids undergo extensive first- pass metabolism so only a small portion of the drug reaches the systemic circulation; the 10-20% that is
not swallowed is deposited in the lungs


systemic corticosteroids

used in patients with severe exacerbation of asthma (status asthmaticus) and are given IV as methylprednisolone (Solu-Medrol) or orally; once the patient has improved, the dose of drug is gradually decreased leading to discontinuance in 1-2 weeks



a spacer is a large volume chamber that is attached to the metered-dose inhaler and is used to decrease the deposition of drug in the mouth; the chamber reduces the velocity of the injected aerosol and also serves as a type of filter to allow mainly small drug particles to be deposited in the mouth; the small particles are more likely to reach the target airway tissue

rinsing the mouth after inhalation can also decrease systemic absorption and the possibility of oropharyngeal candidiasis (thrush)



in the inhaled form, thrush may be a problem; when given orally or parenterally a number of adverse effects can be observed


Cromolyn and Nedocromil use

Are effective as prophylactic antiinflammatory agents, but are not useful in managing an acute asthma attack because they are not direct bronchodilators
Therapeutic use: mild to moderate asthma; pretreatment with either drug prevents exercise-induced and allergen-induced asthma; especially useful in children due to effectiveness and few side effects (better than corticosteroids)


Cromolyn and Nedocromil moa

these drugs inhibit pulmonary mast cell degranulation in response to a variety of stimuli which, in turn, prevents the release of histamine and other granular contents


Cromolyn and Nedocromil kinetics & adverse

Pharmacokinetics: both drugs are given by inhalation (MDI)
Adverse effects: usually infrequent and minor; rare instances of anaphylaxis, laryngeal edema, headache, rash, and nausea have been reported (cromolyn is touted as the “least toxic drug” used to treat asthma; adverse effects in 0.01% of patients)


Muscarinic Antagonists drugs

Ipratropium (SAMA) and tiotropium (LAMA) are antimuscarinics


Muscarinic Antagonists use

variable among asthma patients and is often assessed on an individual basis; differences in parasympathetic tone probably account for the differences; useful in patients unable to take 2 –agonists; not used for acute asthma attacks


Muscarinic Antagonists moa

blocks muscarinic receptors (M1, M2, M3) thereby reducing parasympathetic flow and blocking contraction of bronchial smooth muscle; tiotropium differs by blocking only M1, M3 receptors


Muscarinic Antagonists kinetics & adverse

Pharmacokinetics: given as an inhaler; slow onset; is sometimes used in combination with a 2 –agonist (albuterol) in a drug called Combivent or Duoneb for COPD; usually given on a regular basis 4 times a day
Adverse effects: minimal since very little systemic absorption occurs



Previously was the primary drug used in asthma therapy but has now been largely replaced by 2 –agonists and corticosteroids; is part of a family of compounds known as the xanthines of which caffeine is a member


Theophylline use

limited use in asthma patients; not recommended for acute attacks; given chronically, may reduce asthma symptoms and reduce the need for inhaled 2-agonists and/or inhaled corticosteroids; sustained-release form is effective for nocturnal asthma


Theophylline moa

inhibition of phosphodiesterase III (PDE III) found in airway smooth muscle, and PDE IV found in inflammatory cells which results in increased cAMP; the net effect is to relax bronchial smooth muscle and to prevent release of cytokines from inflammatory cells; blocks adenosine receptors


Theophylline kinetics & adverse

Pharmacokinetics: a variety of factors influence the pharmacokinetics of theophylline including food, smoking, age, and other drugs; given orally, rectally, or parenterally
Adverse effects: theophylline and caffeine have a number of physiological effects on the CNS and the cardiovascular system, and have diuretic actions; GI effects are most prominent


Leukotriene antagonists (zafirlukast, montelukast, zileuton) moa

act by blocking the leukotriene receptor – cys-LT1 (zafirlukast, montelukast) or by blocking the 5-lipoxygenase enzyme (zileuton) and inhibiting the formation of leukotrienes; leukotrienes, like histamine, are local inflammatory mediators and bronchoconstrictors


Leukotriene antagonists (zafirlukast, montelukast, zileuton) use

alternatives to inhaled steroids in mild asthmatics or as adjuncts to inhaled steroids in severe asthmatics (montelukast used in kids age 1 and over and adults; zafirlukast children age 5 and older; zileuton age 12 and over)


Leukotriene antagonists (zafirlukast, montelukast, zileuton) kinetics & adverse

Pharmacokinetics: given orally (may improve compliance)
Adverse effects: headache is the main adverse effect (13% of patients)



is a monoclonal antibody that inhibits the immune response (anti IgE) in moderate to severe allergen-induced asthma; the product appears safe and effective in patients
12 and older; it is given as an injection under the skin very two to four weeks; anaphylaxis and a slight increased risk for cancer have been reported as side effects


Choice of drugs for exercise-induced asthma

inhaled 2 agonists have the highest efficacy and are the agents of choice for prophylactic therapy
cromolyn is preferred is patients intolerant to inhaled 2 agonists