Antihistamines

Question 1

Mast cell pool

Answer 1

• circulating basophils
• tissue mast cells

Question 2

Non-mast cell pools

Answer 2

• GI
• Lungs
• Skin
• Brain

Question 3

5 contents of mast cell granules

Answer 3

• histamine
• serotonin
• heparin protein complex
• proteolytic enzymes
• autocoids

Question 4

Pre capillary arteriole

Answer 4

• H1 receptor
• dilation -> hypertension

Question 5

Post capillary venule

Answer 5

• H1 receptor
• incr. permeability-> edema

Question 6

Cardiac histamine release

Answer 6

• H2 receptors
• +ve inotrope and chronotrope ->tachycard.

Question 7

Smooth muscle histamine release

Answer 7

• H1
• contraction of bronchi & GI -> bronchospasm/contraction/constriction

Question 8

Shock organs

Answer 8

Tissue has high mast cell conc.

Question 9

Animals whose shock organs are “Lungs”

Answer 9

• cat
• ruminants
• pig
• humans
• guinea pigs

Question 10

Animals whose shock organ is the GIT

Answer 10

• Horse
• pig
• K9 (emphasis on liver)

Question 11

H1 receptors

Answer 11

• inflammation
• anaphylaxis/allergies/drug rxns

Question 12

What do H1 receptors cause

Answer 12

• bronchoconstrict.
• hypotension

Question 13

H2 receptors

Answer 13

Gastric acid secretion

Question 14

H3 receptors

Answer 14

NT release

(Periphery & terminal)

Question 15

H4 receptors

Answer 15

Cell types assc. W/ inflammation

Question 16

What in the GIT constantly secretes histamine

Answer 16

By gastric mucosa

Question 17

HCl secreted by

Answer 17

Parietal cells

Question 18

H1 antihistamines affect what tissues

Answer 18

Bronchial, intestinal, uterine, vascular. Smooth m.

Question 19

H1 antihistamines at vasculature

Answer 19

• goal= stabilize
• antagonize arterial vasodilat. & venous leaking

Question 20

H1 antihistamines in smooth m.

Answer 20

• goal= relaxation
• decr. Bronchoconstriction

Question 21

H1 receptors at ECF

Answer 21

• Goal= decrease
• minimize local & systemic swelling

Question 22

H1 histamines at inflamm. mediators

Answer 22

• goal: decr. Release of hist.
• decrease inflammatory response

Question 23

Alternate antihistamines are

Answer 23

Physiologic antagonists w/ opposite response of histamine

Question 24

Antihistamines do not

Answer 24

Block histamine release & don’t compete

Question 25

Antihistamines for acute anaphylaxis

Answer 25

• sympathomimetics

(Epineph, ephedrine, isoprotenol)

Question 26

Antihistamines for bronchoconstriction

Answer 26

Epinephrine (sympathomimetic)

Question 27

Antihistamines that decrease histamine assc. inflammatory response

Answer 27

• Glucocorticoids
• prednisone and dexamethasone

Question 28

Antihistamines that prevent degranulation

Answer 28

Glucocorticoids (used to pre-treat)