Autacoids - Histamine Flashcards

1
Q

Most important amine autacoids

A

Histamine & serotonin

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

Ergot alkaloids have effects on _____ and _____

A

Serotonin receptors, smooth muscles

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

Ergot alkaloids act on which organs.

A

CNS, pituitary, uterus, blood vessels

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

Histamine is stored in which cell types?

A

Mast cells, enterochromaffin cells, gut, neurons

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

How can histamine be detected in the body?

A

Level of Imidazole acetic acid in the urine

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

Pathophysiologic role of Histamine

A

Seasonal rhinitis (hay fever), Urticaria, Angioneurotic edema, control of stomach acid secretion

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

Modulates smooth muscle contraction, neurotransmitters and for vasodilation

A

H1

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

Give H1 and H2’s signal transduction unit.

A

Gq/G11, Gq/G11, Gs (respectively)

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

These histamine receptors act on Gi/Go subunits.

A

H3, H4

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

All Histamine receptors except _____ can be found at the brain.

A

H4

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

Give locations of each Histamine receptor.

A

H1: Heart, brain, mast cells
H2: Heart, brain, neutrophil, parietal cell
H3: Brain, PNS
H4: Blood cells (mast, eosino, monocyte)

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

Give the physiological function of each Histamine receptor.

A

H1: smooth ms contraction, modulates neurotransmitters, vasodilate
H2: (+) gastric acid, leukocyte function
H3: CNS activity
H4: allergic reaction

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

This H1 receptor antagonist has strong sedative effects and can pass BBB.

A

1st generation agents

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

Give the characteristics of Second generation H1 receptor antagonists.

A

Metabolized by CYP3A4, less lipid soluble, less sedative (less CNS distribution)

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

H1 receptor antagonists reach peak blood concentration in ___ hours and has a duration of action of ___ hours.

A

1-2, 4-6

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

Which H1 receptor antagonist drug acts as an exception by having a longer duration of action?

A

Meclizine (Bonamine) (12-24 hours)

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

H1 antagonist: ______ moiety; H2 antagonist: _________ ring

A

ethylamine, imidazole

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

H1 receptor pharmacodynamics: _____ antagonism; mast cell stabilization at ____ doses

A

reversible competitive, low

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

H1 receptor blockers effects on HR, blood vessels, blood pressure

A

increase (tachycardia), inhibits vasodilator effects (vasoconstrict)

20
Q

H1 receptor blockers affect the cortex (excites and depresses), chemoreceptor trigger zone and vomiting center (T/F).

A

TRUE

21
Q

H1 receptor blockers have an anesthetic-like action and is antipruritic to ______ (CNS/PNS).

A

PNS

22
Q

H1 receptor blockers are broncho______.

A

Bronchodilators

23
Q

Second generation H1 antagonists are used for _____ and ______.

A

Allergic rhinitis, chronic urticaria

24
Q

Which drug/s are best used for motion sickness and vestibular disturbances?

A

Scopolamine, certain 1st Generation H1 antagonists

25
Q

Which drug/s has/have the best effectiveness in treating motion sickness and induces sedation?

A

Diphenhydramine, Promethazine

26
Q

Which drug can treat motion sickness but is less sedating than diphenhydramine?

A

Piperazines (Meclizine)

27
Q

2nd Generation H1 Antagonists are more sedating and are more lipid soluble than 1st Generation.

A

FALSE

28
Q

Side effects of H1 receptor antagonists are anticholinergic in nature. (T/F)

A

FALSE (Antimuscarinic: dry mouth, blurred vision)

29
Q

2nd Generation H1 Antagonists are contraindicated with what 2 KINDS of drugs?

A

Antifungal (ketoconazole, itraconazole), macrolide antibiotics (erythromycin, azithromycin, clarithromycin)

30
Q

H1 antagonists when combined with drugs that depress the CNS produce additive effects. (T/F)

A

TRUE

31
Q

Ethanolamine used for allergies, produces marked sedation.

A

Hydroxyzine (Atarax) 15-100 mg

32
Q

Piperazine derivative ised as anti-motion sickness and produces slight sedation.

A

Cyclizine (Marezine) and Meclizine (Bonamine) 25-250 mg

33
Q

Alkylamines commonly used for “cold” medications. Produces slight sedation.

A

Chlorpheniarmine (Chlor-Trimeton) 4-8mg

34
Q

Phenothiazine derivative used as antiemetic, a-block, and produces marked sedation.

A

Promethazine (Phernergan) 10-25 mg

35
Q

Fexofenadine (Allegra) is a 2nd generation antihistamine which is given at what usual dose?

A

60mg

36
Q

Loratadine (Claritin) & Desloratadine (Clarinex) are longer acting antihistamines. (T/F)

A

TRUE

37
Q

H2 receptor antagonists are rapidly absorbed in the _____.

A

Intestine

38
Q

Cimetidine, ranitidine and famotidine undergoes first-pass hepatic metabolism, giving a 50% bioavailability. (T/F)

A

TRUE

39
Q

H2 antagonists exhibit what kind of inhibition?

A

Competitive

40
Q

H2 antagonists are (highly/not highly) selective and (do/do not) affect H1 or H3 receptors.

A

highly, do not

41
Q

H2 antagonists reduce bicarbonate secretion by histamine, gastrin and cholinomimetic agents. (T/F)

A

TRUE

42
Q

Give 2 diseases inhibited by H2 blockers.

A

GERD, gastric erosions and hemorrhage

43
Q

Diarrhea, headache, fatigue, myalgias, mental status changes, and constipation are common adverse effects of which blockers?

A

H2 blockers

44
Q

Which specific H2 blocker interferes with CYP450 metabolism pathways (CYP1A2, 2C9, 2D6, 3A4)?

A

Cimetidine

45
Q

Give 4 H2 blockers (Drugs) which can prevent GERD and stress ulcers.

A

Cimetidine, famotidine, ranitidine, nizatidine

46
Q

H3 blockers help correct sleep disorders, narcolepsy, obesity and cognitive and psychiatric disorders, and gastric hemorrhage. (T/F)

A

FALSE (No gastric hemorrhage)

47
Q

Tiprolisant is an ___ blocker that can reduce sleep cycles with narcolepsy.

A

H3