drug therapy to decrease histamine effects and allergic response

Question 1

what is histamine

Answer 1

1st chemical mediator released, found in mast cells and basophils, released in response to stimuli (allergic reactions, cellular injury), after its release its target cells are in the blood vessels(eyes), respiratory(lungs) and GI tract

Question 2

when histamine stimulates its receptors what happens

Answer 2

contraction of smooth muscles in respiratory tract(respiratory distress), stimulation of vagus nerve, increased permeability of veins and capillaries(edema), increased secretion from mucus glands, stimulation of peripheral nerve endings, dilation of capillaries in skin, increase secretion of gastric acid, increased heart rate and force

Question 3

hypersensitivity reactions involves

Answer 3

an exaggerated allergic response (anaphylactic)

Question 4

hypersensitivity reactions can cause

Answer 4

tissue damage and serious illness

Question 5

hypersensitivity reactions are caused by

Answer 5

abnormal immune reaction

Question 6

four types of hypersensitivity based on the producing mechanism

Answer 6

types I,II,III are antibody molecules, type IV are antigen specific T cells

Question 7

type 1 hypersensitivity or immediate hypersensitivity is what

Answer 7

occurs within minutes, IgE induced mast cell activation, usually after 2nd or later exposure, mild to severe (mild= itching, rhinitis/ severe= anaphylaxis- respiratory distress cardiac collapse, life threatening

Question 8

type II hypersensitivity or cytotoxic

Answer 8

mediated by IgG or IgM, generates direct damage to cell surface, blood transfusion reactions, hemolytic disease of newborns/ hemolytic anemia

Question 9

type III hypersensitivity or immune complex

Answer 9

mediated by IgG or IgM, forms antigen(bad guy)-antibody(good guy) complexes (acute inflammatory reaction in tissue), serum sickness

Question 10

type IV hypersensitivity or delayed hypersensitivity

Answer 10

cell-mediated response, sensitized T lymphocytes react with antigen to cause inflammation, tuberculin test, contact dermatitis, graft rejection

Question 11

T or F. histamine is the first chemical mediator released during inflammatory response

Answer 11

true; histamine is the first chemical mediator released during immune and inflammatory response. it is synthesized and stored in most body tissues

Question 12

T or F. four classifications or hypersensitivity reactions exist

Answer 12

true; Type I(immediate), II(direct damage to cell surfaces), III(formation of antigen-antibody complexes), IV(delayed hypersensitivity)

Question 13

allergic rhinitis is what

Answer 13

inflammation of nasal mucosa caused by type I reaction to inhaled allergens

Question 14

s/sx of allergic rhinitis

Answer 14

nasal congestion, itching, sneezing, watery drainage, itching of throat, eyes, ears

Question 15

seasonal disease of allergic rhinitis

Answer 15

aka hay fever, response to airborne pollens

Question 16

perennial disease of allergic rhinitis

Answer 16

response to nonseasonal allergies, dust mites/ molds, animal dander

Question 17

allergic food reactions

Answer 17

immune response to ingestion of a protein

Question 18

what are high risk foods that could trigger anaphylaxis

Answer 18

shellfish, fish, corn, seeds, bananas, egg, milk, soy, peanut, tree nuts

Question 19

children allergic to milk, eggs, wheat, and soy may what

Answer 19

may outgrow their allergy, no way to prevent food allergies

Question 20

what is contact dermatitis

Answer 20

type IV (delayed) reaction from direct contact with antigen

Question 21

examples of contact dermatitis

Answer 21

poison ivy, cosmetics(tattoo ink), metals(necklaces, rings)

Question 22

s/sx of contact dermatitis

Answer 22

inflamed, warm, swollen itchy skin/ blisters may form, drain and become infected

Question 23

allergic reactions from drug reactions

Answer 23

any drug may cause reaction, any body tissue may be involved, symptoms vary (skin rash, itching, fever, hematologic or hepatic reactions), may occur 7-10 days after initial exposure, resolves after drug discontinued

Question 24

T or F. allergic rhinitis is caused by type III sensitivity

Answer 24

false; allergic rhinitis is inflammation of nasal mucosa caused by type I hypersensitivity reaction to inhaled allergens

Question 25

what are antihistamines

Answer 25

relieve symptoms but do not relieve hypersensitivity

Question 26

antihistamines can help in what ways

Answer 26

help relieve symptoms of allergic rhinitis, anaphylaxis, drug allergies, dermatologic conditions, allergic conjunctivitis (itchy red eyes), blood/ blood transfusion reactions

Question 27

antihistamine: first generation H1 receptor antagonists example med

Answer 27

diphenhydramine

Question 28

what does diphenhydramine do (block histamine receptor)

Answer 28

prevent/reduce most physiologic effects that histamine produces at receptor sites, inhibits smooth muscle constriction in blood vessels/respiratory/GI tract, decrease capillary permeability, decrease salivation and tear formation

Question 29

mechanism of action for first generation H1 receptor antagonists

Answer 29

occupy same receptors as histamine which prevents histamine from reaching target (block histamine receptor)

Question 30

uses for first generation H1 receptor antagonists

Answer 30

allergic reaction, motion sickness, insomnia, children may experience paradoxical effect(opposite effect, make kids hyper)

Question 31

adverse effects of first generation H1 receptor antagonists

Answer 31

CNS depression(drowsy), anticholinergic effects(dy mouth, constipation)

Question 32

contraindications for first generation H1 receptor antagonists

Answer 32

narrow angle glaucoma, BPH

Question 33

nursing considerations for first generation H1 receptor antagonists

Answer 33

use caution in older adults, may cause confusion, may thicken secretions

Question 34

patient education for first generation H1 receptor antagonists

Answer 34

take med before exposure to allergen, tolerance to drowsiness in few days, avoid taking with alcohol, avoid accidental OD

Question 35

antihistamine: second generation H1 receptor antagonists example med

Answer 35

fexofenadine, loratadine, cetirizine

Question 36

what are second generation H1 receptor antagonist

Answer 36

does not readily enter the brain from the blood(don’t cross blood brain barrier, do not make you drowsy), bind preferentially to peripheral rather than central H1 receptors, replacing first germination H1, have a mild beneficial effect in chronic asthma

Question 37

mechanism of action for second generation H1 receptor antagonist

Answer 37

occupy same receptors as histamine which prevents histamine form reaching target (blocks histamine receptors)

Question 38

uses for second generation H1 receptor antagonist

Answer 38

seasonal allergic rhinitis, minor allergies, itching

Question 39

nursing considerations for second generation H1 receptor antagonist

Answer 39

safer in older adults(because not affected in CNS, non drowsy), use caution in renal failure

Question 40

patient education for second generation H1 receptor antagonist

Answer 40

take med before exposure to allergen, teach proper use of nasal spray if needed, avoid taking with alcohol, avoid accidental OD

Question 41

when explaining the options for antihistamine to a patient, the nurse explains that second generation H1 antagonists differ from first generation antagonists by

Answer 41

do not cross the blood brainer barrier/ reducing side effect of sedation (drowsy)