Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Pharm > Lecture 9- Histamine > Flashcards

Lecture 9- Histamine Flashcards

1
Q

What cell type is histamine mostly found in?

A

Mast Cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where are the highest amounts of histamine found?

A

Lung, skin, nasal and Gi mucosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Mast cells have high affinity _______ binding sites on their plasma membranes.

A

IgE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Histamine is formed by decarboxylation of what amino acid?

A

Histidine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Histamine is stored in _______.

A

Granules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are some instances where histamine is released?

A 
Trauma
Allergies
Anaphylaxis
Cold
Bacterial toxins
Bee strings
Venom
Drugs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the 2 types of histamine release from mast cells?

A

Cytolytic release

Noncytolytic release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What causes cytolytic release of histamine?

A

Damage to plasma membrane then there is leakage of cytoplasmic contents

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What 2 things induce cytolytic release of histamine?

A

Phenothiazines

Narcotic analgesics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What type of histamine release requires ATP and calcium?

A

Noncytolytic release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What causes histamine release in noncytolytic release?

A

IgE antibodies binding to antigen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

These 6 drugs (d-tubocurare, succinylcholine, morphine, codeine, doxorubicin, protamine) can cause what with histamine?

A

Stimulate histamine release from mast cells without prior sensitization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What drug causes red man syndrome- flushing, pruritus, chest pain, muscle spasms and hypotension?

A

Vancomycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What can help reduce the symptoms of red man syndrome?

A

Pretreatment with IV antihistamines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are 2 inhalation powders that block the release of histamine from mast cells?

A

Cromolyn

Nedocromil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are Cromolyn and Nedocromil used for?

A

Decrease symptoms of allergic rhinitis

Used to block asthmatic rxns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Are Cromolyn and Nedocromil effective during an actual asthma attack?

A

No, only preventative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which histamine receptor uses adenylyl cyclas mechanism and parietal cell acid secretion?

A

H2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Which histamine receptor is proinflammatory activity?

A

H4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What histamine receptor is on neurons and inhibits the release of histamine (feedback inhibition)?

A

H3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Which histamine receptor uses phospholipase C mechanism (respiratory and allergic reactions)?

A

H1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which histamine receptor increases mucus in nasal cavity and bronchi resulting in respiratory symptoms

A

H1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What histamine receptor stimulates gastric secretions?

A

H2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Which histamine receptor constricts bonrchi and intestines (cramps, diarrhea)?

A

H1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
The activation of which histamine receptor leads to the stimulation of sensory nerve endings (itching/ pain)?
H1
26
How does histamine directly increase HR and contractility?
Increasing influx of calcium
27
How does histamine indirectly increase HR and contractility?
Baro-receptor mediated increase in sympathetic tone in response to histamine induced vasodilation
28
What are the 2 ways H1 leads to vasodilation?
Decrease in blood pressure | increase in nitric oxide
29
Is there a release of catecholamines from the adrenal medulla in allergy and anaphylaxis?
Yes
30
What are the three parts of the triple response of lewis?
Red line/ spot Flare (large area of red around) Wheal (edema)
31
In hypersensitivity rxns what are the 2 principle targets?
Mast cells and Basophils
32
What happens in an allergic response?
An antigen produces the formation of IgE antibodies which bind to high affinity receptors specific for these IgE antibodies and activates tyrosine kinase
33
The activation of phospholipase A2 produces _________ and __________.
Leukotrienes | Prostaglandins
34
____________ contract smooth muscle of the bronchi. Are involved in hypersensitivty rxns?
Leukotrienes
35
What happens if histamine is released rapidly and diffuses via the blood then the response may be full-blown .
Anaphylactic reaction
36
What do you treat true anaphylaxis with?
Epinephrine
37
What is histamine phosphate used for?
to assess nasal and bronchial reactivity | for allergy skin testing
38
What should individuals discontinue before allergy skin testing with histamine phosphate?
antihistamines, tricyclic antidepressants, corticosteroids, benzodiazepines.
39
1st generation antihistamines block which histamine receptor?
H1
40
What are the 5 hisatmine H1 receptor blockers, first generation?
``` triprolidine diphenhydramine promethazine hydroxyzine chlorpheniramine ```
41
What is the benefit of 2nd generation H1 receptor blockers?
Less CNS toxicity or side effects since they don't cross the BBB and are excluded by p-glycoprotein
42
What are the 4 second generation H1 receptor blockers?
loratadine (Claritin, OTC), desloratadine (Clarinex), azelastine (Astelin) , cetirizine (Zyrtec,OTC)
43
What effects are lesser in reversible, competitive blockers of H1 receptors?
Less effect on bronchoconstrction and vasodilation which are caused predominatly by prostaglandins and leukotrienes
44
For H1 blockers is there a tolerance to the suppressive effect on skin test reactivity to allergens?
No
45
Tolerance to what effect of H1 blockers may occur?
Sedative effects
46
What is the active metabolite of loratadine (Claritin)?
Desloratadine (Clarinex)
47
What is the metabolite of terfenadine (Seldane)?
Fexofenadine (Allegra)
48
What is terfenadine metabolized by?
CYP3A4 family
49
Is terfenadine currently on the market?
No- it was withdrawn due to risk of life threatening cardiac arrhytmias, torsades de pointes
50
What do all FDA approve antihistamines no prolong?
QT interval
51
What is the main difference b/w 1st and 2nd generation H1 blockers?
2nd generation have no anticholinergic affect, no CNS sedation and are longer acting
52
What allergic conditions do antihistamines (H1) treat?
Allergic rhinitis Urticaria Allergic drug rxns (prophylactic) Allergic conjunctivitis
53
What is the most effective antihistamine used for prevention of symptoms of motion sickness?
Promethazine
54
What are 3 other antihistamines (besides promethazine) used for prevention of motion sickness?
diphenhydramine, cyclizine, meclizine
55
When should you administer promethazine?
1 hour before anticipated motion
56
What is the most effect drug (not an antihistamine) used to prevent motion sickness?
Scopolamine
57
WHat drug class is used to prevent nausea and vomiting?
Phenothiazine class
58
What are 2 drugs in the phenothiazine class that are used to prevent N/V?
Promethazine | Timeprazine
59
How does the phenothiazine class work?
Blocks dopamine D2 receptors
60
What drug is used for OTC treatment of hyposomnia?
Diphenhydramine
61
How many consecutive nights should antihistamines used for sleep medications be limited to?
10 consecutive nights
62
What antihistamine drug is used for antiparkinsonism effect, especially antimuscarinic actions.
Diphenhydramine
63
What antihistamine is found in sunburn preparations for local anesthetic actions?
Promethazine
64
How do antihistamines work as local anesthetics- specifically what channels do they block?
Block sodium channels
65
What is an antihistamine used to treat oral ulcers, infections, inflammation and pain?
Magic Mouthwash
66
What are the 2 main adverse effects of antihistamines?
Antimuscarinic and sedative actions (usually lower with second generation)
67
What does CNS sedation correlate with for antihistamines?
H1 receptor binding in brain
68
What are some of the anticholinergic effects associated with antihistamines?
Dry mouth and nasal passages Constipation Blurred vision Urinary retention
69
What can occur in children who are given antihistamines?
Paradoxical excitation
70
Combing CNS H! antagonists with what other medications can be dangerous?
Other sedating medications
71
H1 antagonists potentiate _________________
all other CNS depressants
72
What population is acute poisoning with H1 antagonists relatively common?
Young children
73
What are the acute effects of poisoning with H1 antagonists?
initial excitement ataxia and convulsions coma and cardiorespiratory collapse

Pharm (29 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions