Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pulmonary > PHARM: Antihistamines > Flashcards

PHARM: Antihistamines Flashcards

1
Q

What are the three roles of antihistamines?

A

1) Endogenous mediator of vascular and smooth muscle tone
2) Principle regulator of gastric acid secretion
3) Neurotransmitter

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

How many histamine receptors are there?

A

4 (H1-H4)

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

Which histamine receptors have drugs directed against them?

A

H1 and H2 only

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

What are the pathophysiological effects of histamine?

A

Edema
Itching
Rhinitis

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

Through which receptors is the edema, itching, and rhinitis caused by histamine mediated?

A

H1 receptors

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

Where are H2 receptors located?

A

primarily in the GI tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Explain the biosynthesis of histaine?

A

L-histidine and water are converted into histamine and CO2 by L-Histidine decarboxylase

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

Where is histamine synthesized (mainly)?

A

Mast cells

Basophils

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

List some activators of histamine release.

A 
GM-CSF
IL-3
Endotoxin (bacterial infection)
PGs
IgE-immune/allergic response
kinins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are some inhibitors of histamine release?

A

histidine analogs
Beta-antagonists
cromolyn Na+

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

What is involved with Th-1 inflammatory response?

A

Allergen–>IL-12 stimulates Th1 cells–> IFN-gamma is released –> stimulates cytotoxic T cells and also stimulates B cell to make IgG

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

What is involved with a Th-2 inflammatory response?

A

Allergen==> Th-2 cell releases IL-3, IL-5, GM-CSF–> stimulates eosinophils

Th-2 also releases IL-4 which tells B cells to make Ig-E to interact with mast cells

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

HOw is IgE involved with histamine release?

A

IgE binds to Fc receptors of mast cells and multivalent antigen cross-links adjacent IgE molecules (leading to histamine release by exocytosis)

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

What are the primary roles of H1 receptors?

A

smooth muscle contraction
stimulation of NO formation
endothelial cell contraction
increased vascular permeability

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

What is the primary role of H2 receptors?

A

stimulation of gastric acid secretion

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

What is the primary role of H3 eceptors?

A

inhibition of neurotransmitter release

17
Q

H1 receptors act via which molecules?

A

guanylate cyclase increasing cGMP (leading to increased PG)

18
Q

H2 receptors act via which molecules?

A

adenylate cyclase increasing cAMP (leading to increased PG)

19
Q

What ae the major vasculature effects of histamine (and what receptors)?

A 
Microvasodilation (H1 and H2)
Capillary permeability (H1)
Vasoconstriction (H1)
20
Q

What are the major pulmonary effects of histamine (and what receptors)?

A

Bronchoconstriction (H1)

Bronchodilation (H2)

21
Q

What are the major neural effects of histamine (and what receptors)?

A

Nerve ending stimulation (H1, H3)

Wakefulness and sedation (H1 and H3)

22
Q

How do first generation antihistamines differ from second generation?

A

first generation are short-acting, can cross the BBB (have associated sedation), and have anti-cholinergic effect (bind to muscarinic receptors impairing ciliary movement and mucus clearing).

Second generation are longer acting, do NOT cross the BBB, and are safer for asthmatics (because they do not have anti-cholinergic effects)

23
Q

How do the structures of first and second generation antihistamines differ?

A

first generation is based on the structure of histamine and second generation is not

24
Q

List the 1st generation antihistamines.

A

ETHER DERIVATIVE
Diphenhydramine
Dimenhydrinate

ALKYLAMINE DERIVATIVE
Chlorpheniramine

PHENOTHIAZINE DERIVATIVE
Promethazine

25
Q

What are therapeutic applications for H1 antagonists?

A

allergy/hayfever symptoms
Bug bites/stings
motion sickness/vertigo

26
Q

List some side effects of first generation H1 antagonists?

A

Sedation, decreased alertness, dizziness, dystonia, etc.

27
Q

True or false: H1-receptor antagonists are selective but not specific.

A

TRUE!
Diphenhydramine and promethazine can also inhibit muscarinic recptors and promethazine can inhibit alpha-adrenergic receptors!

28
Q

List the second generation H1 antagonists.

A

Fexofenadine

PIPERDINE DERIVATIVES
Loratadine

PIPERAZINE DERIVATIVES
Cetirizine

29
Q

What are some side effects of 2nd generation H1-antagonists?

A

Mild cognitive disturbances

appetite stimulation

Pulmonary (34 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions