chapter 31 Antihistaminic drugs and mast cell stabilizers
Terms in this set (15)
what is released when the body comes into contact with an allergen, anaphylaxis can cause death
how does histamine work?
it interacts with membrane receptors, and has H1-H4 receptors with H1 located on blood vessels, bronchiolar smooth muscle, intestinal smooth muscle to mediate allergic reaction
what is the process of a reaction?
binds to IgE on surfaces of mast cells and basophils
release of histamine
because histamine can cause a decrease in blood pressure, erythema, edema, hives, itching, and pain, what are some major effects that easily get out of hand?
~can increase peristalsis
~rapid heart beat, breathing difficulty
~dilates blood vessels, decrease in blood pressure
allergic reactions can be blocked by
~preventing mast cells from releasing content
~blocking H1 receptors
what do mast cell release inhibitors (MCRI) do?
prevent the mast cell from breaking down ALSO/ mast cell stabilizers
what is an example of an MCRI and its MOA?
cromolyn sodium, it selectively prevents release of histamine from mast cells
What does MCRI's reduce?
itching, hyperemia, mucous discharge
what are the adverse effect of MCRI's?
Wheezing, nasal itching, nausea, drowsiness
What do antihistamine H1 agonists do, and what is their special action?
block histamine from binding to the H1 receptor
~relieves symptoms of allergic reactions after histamine has been released
what is a first generation order?
non-selective interactions with peripheral and CNS histamine receptors
what is a second generation order?
more selective, block peripheral, aren't as sedating but work just as well, don't dry eyes, out, throat, OTC
what do antihistamine agonists treat?
itching, hay fever, dermatitis, motion sickness, sleep aid
what are side effects and adverse effects of antihistamine agonists?
drowsiness; hypotension, rapid heartbeat, anorexia, heart burn, urinary retention
what are contraindications for antihistamine agonists?
cardiovascular disease,e hypertension, prostate enlargement; should not be used in pregnancies or nursing women, infants