Respiratory Meds Flashcards
A 20-year-old male with moderate to severe asthma is taking an inhaled corticosteroid and a long acting beta-agonists but his symptoms are still poorly controlled. His physician recommends adding theophylline and reviews the common side effects of the drug. Which of the following side effects is NOT commonly associated with theophylline?
A. Hepatotoxicity
B. Nervousness
C. Tachycardia
D. Tremor
A. Hepatotoxicity. Patients taking theophylline should be counseled that they may experience tremors, nervousness and tachycardia. Theophylline has a narrow therapeutic index and patients with a toxic serum drug level may have hypokalemia, hyperglycemia, nausea, vomiting, cardiac arrhythmias, as well as seizures. Hepatotoxicity is not commonly associated with theophylline. Zileuton, another asthma medication, has risk of hepatotoxicity.
An 8-year-old female with exercise induced asthma is prescribed albuterol to use both as prophylaxis before exercise, as well as a rescue inhaler during acute exacerbations. What is the mechanism of action of this drug?
A. Beta-1 receptor agonist
B. Beta-2 receptor agonist
C. Beta-3 receptor agonist
C. Non-selective beta receptor agonist
B. Beta-2 Agonist. The beta-2 receptor mediates bronchodilation. Albuterol is a selective, short acting beta-2 agonist (SABA) used to treat acute asthma exacerbations. Salmeterol and formoterol are long acting beta-2 agonists used as daily controller inhalers. Terbutaline is also a selective beta-2 agonist which treats bronchoconstriction in asthma patients.
Which of the following medications has prolonged duration of action and can be used as maintenance therapy to prophylax against asthma symptoms?
A. Albuterol
B. Ipratropium bromide
C. Methylprednisolone
D. Salmeterol
D. Salmeterol is an inhaled long acting beta-2 agonist, which is useful as maintenance treatment of moderate to severe asthma. Long-acting beta-2 agonists, such as salmeterol and formoterol, have a long duration of action and are used as daily controller inhalers.
Which of the following best describes the mechanism of action of omalizumab?
A. Antagonizes LTD4 receptors
B. Binds to IgE
C. Inhibits lipoxygenase
D. Inhibits phosphodiesterase
B. Omalizumab is an anti-IgE monoclonal antibody which targets the Fc portion of IgE. Omalizumab binds free serum IgE and prevents mast cell sensitization and degranulation. This drug is administered subcutaneously and is indicated for moderate to severe persistent asthma in patients with evidence of allergic sensitization, demonstrated by a positive skin test, for example, and whose symptoms are inadequately controlled with inhaled corticosteroids.
Which of the following correctly describes loratadine’s mechanism of action?
A. Antagonizes H2 receptors on bronchial smooth muscle
B. Inhibits histamine from binding to the H1 receptor
C. Inhibits H2 receptors on gastric parietal cells
D. Inhibits mast cell degranulation
B.
By what mechanism does 1st generation H1-blockers cause dizziness and hypotension?
A. Antagonizing alpha-1 receptors
B. Antagonizing muscarinic receptors
C. Antagonizing serotonin receptors
C. Stimulating beta-1 receptor
A. Alpha-1 adrenergic receptors are responsible for mediating sympathetic nervous system responses including vascular smooth muscle contraction. 1st generation H1 blockers (e.g. chlorpheniramine, diphenhydramine, hydroxyzine, and promethazine) are known to cause dizziness and hypotension by antagonizing the alpha-1 receptors. Both the H1 and alpha-1 receptors are coupled to Gq protein.
Activation of the H1 receptor mediates all of the following physiological reactions EXCEPT:
A. Increased bronchial smooth muscle contraction
B. Increased gastric acid secretion
C. Increased mucus production
D. Increased vascular permeability
B. Enterochromaffin cells release histamine which bind the H2 receptors in the gastric parietal cells. Activation of the H2 receptor increases gastric acid secretion by using the coupled Gs protein to stimulate cAMP production and activate protein kinase A. Gastrin and acetylcholine can also stimulate gastric acid secretion. The H1 receptor does not mediate gastric acid secretion.
