Respiratory Flashcards
where is the site for gas exchange
type 1 alveolar cells
type of cell that produces surfactants that are secreted onto the inner surface of the alveoli
type II alveolar cells
action of surfactant
reduces water surface tension and supports inflation of the lungs
what do elastic fibers do?
they surround alveoli and are stretched during inflation and recoil during expiration; recoil provides a major force for expelling air from the lungs
PNS effect on the lungs
bronchoconstriction mediated by muscarinic cholinergic receptors
SNS effect on the lungs
epinephrine causes vasodilation mediated by beta-2 adrenergic receptors
What is the action of mast cells?
mast cells respond to allergens; they bind with IgE antibodies and mediate type 1 hypersensitivity responses leading to a release of histamines
the action of leukocytes and eosinophils in the lungs
respond to inflammatory challenges–> LOX is released –> activating leukotrienes that bind to leukotriene receptors (LTR) –> bronchoconstriction and edema –> congestion and coughing
What is COPD characterized by?
Chronic inflammation of the airways that eventually results in the destruction of elastic fibers that provide recoil forces needed for expiration
MOA of beractant
MOA is a surfactant preparation administered intratracheally; reduces water surface tension in alveoli and makes inflation of alveoli easier
Therapeutic use for beractant
Can be used for preterm infants and for adults experiencing respiratory distress syndrome; pulmonary infections/edema/near drowning events associated w/ dilution of surfactants along the lining of the alveoli
MOA of alpha-1 anti-proteinases
MOA is “replacement” therapy of an alpha-1 proteinase genetic deficiency disorder; this enzyme normally limits the degree of elastic fiber destruction associated with inflammatory states
therapeutic used for alpha-1 anti-proteinases
Used to treat genetically linked forms of emphysema (COPD) that is associated w/ the absence of anti-elastases in leukocytes
Example of an expectorant
guaifenesin
MOA of expectorants
MOA is mild irritants of bronchial glands, stimulates secretion of water that dilutes mucus and makes it easier to dislodge it from airways
Example of a mucolytic
acetylcysteine
MOA of a mucolytic
breaks disulfide bonds within mucoproteins that are secreted by mucus glands; reduces viscosity of mucus and makes it easier to dislodge from airways – used in Tylenol toxicity
Therapeutic use of mucolytics
Treatment of cystic fibrosis, reduces mucus accumulation
Often very bronchospastic so is typically given with albuterol to help bronchoconstriction
MOA of Cromolyn preparations
a mast cell “stabilizer”; reduces mast cell release of histamine in response to an allergen; reduces mucus secretion and congestion
therapeutic use of cromolyn preparations
Prophylactic treatment of asthma attacks and allergies
Often used for exercise induced asthma
Examples of antihistamines
diphenhydramine and loratadine
MOA of antihistamines
MOA is an H1 histamine receptor antagonist; reduces histamine induced mucus secretion and congestion
therapeutic use of antihistamines
Treatment of acute allergic reactions: rhinitis, urticaria, and conjunctivitis; motion sickness
difference between diphenhydramine and loratadine
Loratadine is a 2nd generation antihistamine that does not pass BBB as readily as 1st generation… reduces CNS depression
Example of monoclonal anti- IgE antibodies
omalizumab
MOA of monoclonal anti-IgE antibodies
selectively binds to IgE antibodies in the blood which prevents them from attaching to mast cells, thus preventing the release of histamines
therapeutic uses of monoclonal anti-IgE antibodies
Used to treat moderate to severe forms of allergic asthma; advantages include improved lung function, a reduction in asthma attacks, and reduced treatment w/ glucocorticoids
Example of an anticholinergic
ipratropium
MOA of anticholinergics (ipratropium)
MOA is muscarinic cholinergic receptor antagonist; Inhaler
therapeutic uses for anticholinergics
Used to reduce receptor mediated bronchoconstriction associated w resp. Disorders (COPD)
example of a leukotriene system inhibitors
zileuton and montelukast
MOA of zileuton
Zileuton is a lipoxygenase (LOX) inhibitor which acts to block the production of leukotrienes
MOA of montelukast
montelukast is a selective leukotriene receptor antagonist (leukotrienes are still produced but cannot bind)
therapeutic use for leukotriene inhibitors
Used to treat leukotriene mediated bronchoconstriction and often associated w asthma and allergic responses
examples of glucocorticoids (corticosteroids)
beclomethasone, prednisone (intermediate acting) and dexamethasone (long acting)
MOA of glucocorticoids
MOA is cortisol receptor agonists; they stimulate the production of lipocortin which is an inhibitor of phospholipase A2, thus reducing the inflammatory cascade
therapeutic use of glucocorticoids
Used to treat asthma, COPD, allergic rhinitis, derm. Allergies and RA
Example of antitussives
codeine and dextromethophan
MOA of codeine
opioid receptor agonist that suppresses the activation of the cough center in the brain stem
MOA of dextromethorphan
MOA increases the sensory threshold for airway obstruction that activates the cough center (non-addictive, no resp. Suppression) but the precise MOA is unknown… it binds to the NMDA receptor and acts as an antagonist and a sigma-1 agonist.
therapeutic uses of antitussives
cough suppressant associated with non-productive coughs
Examples of bronchodilators
theophylline, albuterol, terbutaline, salmeterol and mag sulfate
MOA of theophylline
a cAMP PDE inhibitor
MOA of albuterol
short acting beta-2 agonist
MOA of terbutaline
a short acting beta-2 agonist
MOA of salmeterol
a long acting beta-2 agonist
MOA of mag sulfate
MOA is not fully understood but evidence suggests that mag interferes w/ calcium channels in smooth muscle and causes muscle relaxation (bronchodilation)
Role of cAMP in bronchodilation of the smooth muscle cell
CAMP promotes relaxation of the bronchial smooth muscle. Phosphodiesterase (PDE) metabolizes cAMP. We don’t want it to be metabolized! We want more cAMP to continue to broncho dilate
therapeutic uses of bronchodilators
used in the treatment of asthma, etc.; theophylline can be used to treat patients who are unresponsive to albuterol and can increase rates of respiration in pre-term infants (increases sensitivity of respiratory control center to pCO2)
Which interleukin binds to eosinophils to encourage eosinophil recruitment
IL-5
Example of a cromolyn preparation
Intal
Risk of Omalizumab
anaphylactic shock; must be given IM in a doctors office and monitored after
Theophylline side effect
Activation of the SNS.. feeling very energized and hyperactive
Children in emergency situations who are having an asthma attack and are unable to inhale albuterol should be given what?
terbutaline subQ
What do eosinophils respond to, to create an inflammatory cascade?
Interleukin-5 (IL-5)
MOA of reslizumab
IL-5 receptor antagonist; blocks the interaction between IL-5 and eosinophils
therapeutic use for reslizumab
severe eosinophilic asthma
