GI Intestine (Akbareli) iii107-213 Flashcards

1
Q

What type of motility is associated with the esophagus?

A

Peristalsis

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

What type of motility is associated with the stomach and small intestine?

A
  1. Non-propulsive segmental contractions

2. Propulsive peristaltic contractions

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

Upon what three things is motility dependent?

A
  1. Myogenic (smooth muscle) effects
  2. Neurogenic (ENS) effects
  3. Humoral effects
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the disorder characterized by impaired relaxation of the LES with defective peristalsis?

A

Achalasia

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

What is the disorder characterized by delayed gastric emptying?

A

Gastroparesis

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

What disorder is characterized by diarrhea and constipation?

A

Intestinal motility disorder(s)

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

What is an example of a functional bowel disorder?

A

Irritable Bowel Syndrome (IBS)

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

What are two examples of inflammatory bowel diseases?

A
  1. Ulcerative Colitis

2. Crohn’s disease

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

What would characterize an ideal pro kinetic agent?

A

One that enhances the release of excitatory neurotransmitters at the nerve ending while still preserving the normal pattern of motility.

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

M2 and M3 are what type of receptors and what cells are they found in?

A

Muscarinic found on smooth muscle cells

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

What cholinergic agent is a structural analog of acetylcholine?

A

Bethenechol

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

What cholinergic agent is not useful as a pro kinetic agent?

A

Bethenechol

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

Which cholinergic agent induced non propulsive contractility?

A

Bethenechol

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

What are side effects of Bethenechol?

A

Cholinergic receptor stimulation

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

What cholinergic agent inhibits degradation of acetylcholine by esterase?

A

Cholinesterase inhibitors

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

What is an example of a cholinesterase inhibitor discussed in class?

A

Neostigmine methylsulfate

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

What cholinergic agent enhances acetylchoiine activity and accelerates GI transit?

A

Neostigmine methylsulfate

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

What cholinergic agent is used in acute colonic pseudo-obstruction / paralytic ileum?

A

Neostigmine methylsulfate

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

What effect does dopamine have on the motor neurons in the myenteric plexus?

A

Inhibits the release of acetylcholine from the motor neurons

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

What effect does a dopamine receptor antagonist have?

A

Enhances the release of acetylcholine (a pro kinetic effect)

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

What is an example of a substituted benzamide?

A

Metoclopramide (REGLAN)

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

What is the effect of 5HT4 agonism?

A

Some central 5HT3 receptor antagonism

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

What are the main effects of dopamine antagonism on the upper GI tract?

A
  1. Increased LES tone

2. Stimulation of the astral and small intestinal contraction

24
Q

What is the some indications for metoclopramide?

A
  1. Gastroesophageal reflux disease (GERD)
  2. Gastric stasis
  3. Diabetic gastroparesis
25
Q

What are some of the therapeutic effects of metoclopramide?

A
  1. Stimulates gastric motility
  2. Stimulates antral and small intestinal motility
  3. Decreases small intestinal transit time by stimulating peristalsis
26
Q

What is the main usage of metoclopramide?

A

Treatment of nausea and vomiting

27
Q

What are the two main adverse effects of metoclopramide?

A
  1. Extrapyramidal effects and parkinsonian-like symptoms.

2. Increase serum prolactin (which may lead to gynecomastia)

28
Q

What is another dopamine receptor antagonist (bedsides meoclopramide) that does not cross the BBB and is not available in the US?

A

Domperidone

29
Q

Where are 90% of the 5HT receptors located?

A

The GI tract

30
Q

Where is the “major storage” of the 5HT receptors?

A

EC cells

31
Q

The submucosal intrinsic primary afferent neurons are activated by what receptor?

A

5HT1p

32
Q

The myenteric intrinsic primary afferent neurons are activated by what receptor?

A

5HT4 (which leads to acetylcholine

33
Q

Is Tegaserod (ZELNORM) is a partial agnostic of what?

A

5HT4

34
Q

Is Tegaserod more effective in males or females?

A

Females

35
Q

What is Tegaserod primarily used for?

A

Constipation-predominant irritable bowel syndrome (IBS)

36
Q

Does Tegaserod stimulate motility?

A

Yes. It accelerates GI transit

37
Q

Is Tegaserod administered orally?

A

Yes. In 2mg and 6mg tablets.

38
Q

What is the main mechanism of action of Cisapride (PROPULSID)?

A

Stimulates 5HT4 receptors

39
Q

What are the indications of Cisapride use?

A
  1. GERD

2. Gastroparesis

40
Q

Why was Cisapride withdrawn from the US market?

A

HERG K+ chennel blocking activity in the heart leading to sudden cardiac death (long QT syndrome)

41
Q

What is a 5HT4 agonist that improves colonic transit in chronic idiopathic constipation and is approved in Europe at this time?

A

Prucalopride (RESELOR)

42
Q

What is a 23 amino acid peptide found in the GI tract and is a potent contractile agent?

A

Motilin

43
Q

Where are motilin receptors located?

A

Smooth muscle and enteric neurons

44
Q

What effect does erythromycin have on motilin receptors?

A

Stimulates them

45
Q

Where is erythromycin mostly effective?

A

The upper GI tract

46
Q

What can happen with erythromycin at doses above 3 mg/kg?

A

Spastic contraction resulting in cramps, impairment of transit and vomiting

47
Q

What is erythromycin generally used for?

A

Diabetic gastroparesis

48
Q

What is the standard dose of erythromycin?

A

200mg to 250 mg every 8 hours

49
Q

Besides erythromycin, what are some other macrolide antibiotics?

A
  1. Oleandomycin
  2. Azithromycin
  3. Clarithromycin
50
Q

What is the effect of cholecystokinin receptor antagonists?

A

Improves gastric emptying

51
Q

What do relaxants such as organic nitrates, and calcium channel antagonists?

A

Relief of increased GI tone

52
Q

What effect does botulinum toxin have on LES tone?

A

Decreases it

53
Q

What is a heterogeneous disorder characterized by difficulty in passage of stools and infrequent defacation pattern?

A

Constipation

54
Q

What are 6 main causes of constipation?

A
  1. Lack of dietary fibers
  2. Drug-induced
  3. Neurogenic disorders
  4. Irritable bowel syndrome
  5. Decreased motility of mass action (propulsive)
  6. Increased non-propulsive motility in the distal colon
55
Q

How do laxatives help relieve constipation?

A
  1. Enhance retention of intraluminal fluid by hydrophilic or osmotic mechanism
  2. Decrease net absorption of fluid by affecting electrolyte transport
  3. Alter motility by inhibition of segmental contractions and enhance peristaltic contractions