Brainscape's Knowledge GenomeTM

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


See full index

Surgery- UGIT (2) > Anti-emetics, Anti-spamodics, Anti-diarrhea, Laxatives And Prokines > Flashcards

Anti-emetics, Anti-spamodics, Anti-diarrhea, Laxatives And Prokines Flashcards

1
Q

What is vomitting?

A

Nausea and vomiting are protective reflexes that rid the stomach and intestine of toxic substances and prevent further ingestion.

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

What autonomic complex process are associated with nausea and vomiting?

A

Pallor
Sweating
Bradycardia
Profuse salivary secretions

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

What part of the brain is responsible for vomiting?

A

Caused by the central coordination by cells in

- The dorsolateral reticular formation in the floor of the 4th ventricle.

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

Name the 3 physiological steps in vomiting:

A
  1. Nausea
  2. Retching
  3. Emesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Explain phase 1 of the physiological steps in vomiting:

A

Nausea:

  • Unpleasant sensation
  • Awareness of an urge to vomit

Accompanied by:

  • Cold sweat
  • Pallor
  • Salivation
  • Disinterest in surroundings
  • Loss of gastric tone
  • Duodenal contractions
  • Reflux of intestinal contents in stomach.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Explain phase 2 of the physiological steps in vomiting:

A

Retching
- Laboured, spasmodic rhythmic contractions of respiratory muscles.
> Diaphragm, Chest wall, Abdominal wall muscles.
- No expulsion of gastric content.
- Normally generates pressure gradient leading to vomiting.

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

Explain phase 3 of the physiological steps in vomiting:

A

Vomiting (Emesis).
- Forceful expulsion of gastric content from the mouth.

Caused by

  • powerful sustained contraction of abdominal muscle.
  • Descent of diaphragm.
  • Opening of gastric cardia.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are 4 mechanisms of vomiting?

A
  1. Stimulation of the higher cortical areas
    • Due to sensory (smell, pain, sight) input, memory, fear anticipation.
  2. Radiation sickness: Stimulates receptors in stomach and small intestines.
    • Radiation, chemotherapy, surgery.
  3. Labyrinth impulse triggers
    • Due to motion sickness, surgery etc.
  4. Stimulation of chemoreceptor trigger zones.
    • Opiods, anaesthetics, chemotherapy, uremia, bacterial toxins.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Name a few causes of vomiting:

A

Radiation sickness
Chemotherapy
Drug induced: estrogens
Metabolic causes: Uraemia, keto-acidosis
Centrally acting emetics: morphine, apo-morphine
Stimulation of higher centers: Psyche, smell etc.
Labyrinth impulses: motion sickness,

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

What is the vomiting center and where is it found?

A

Responsible for central coordination of vomitting act.

  • Group of cells in dorsolateral reticular formation in the floor of the 4th ventricle.
  • It is in close tube cardiovascular and respiratory centers .
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the major efferent pathways involved in the vomiting process?

A

Phrenic nerve
Visceral efferent of vagus to stomach and Oesophagus
Spinal nerves to abdominal muscles.

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

What neuronal receptors are found in the vomit center in the brain?

A
  • AchM
    • H1
    • 5HT2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the chemoreceptor trigger zone.

A

This is a group of neurons in the brain found in the:
- Postrema of the 4th ventricle.

Stimulation of the chemoreceptor trigger zone activates the vomiting center. 
Sensitive to stimuli I.e. 
  - Radiation. 
  - Uraemia.
  - Bacterial toxins.
  - Opiods.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What neuroreceptors are found in the chemoreceptor trigger zone

A

D2
NK1 (Neurokinin)
5HT3

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

What is the vestibular system?

A

These are intracerebral projections leading straight to the vomitting center:

  • There is vestibular stimulation via the cerebellum
  • Main mechanism: Vestibular projections to the CTZ
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What neuroreceptors are found in the vestibular system?

A

H1

AchM

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

What are the major efferent pathways seen in the peripheral pathways?

A

Phrenic nerve
Visceral efferent of Vagus nerve to stomach and oesophagus
Spinal nerves to abdominal muscles

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

Practice: Name the Neuroreceptors and Neural pathway involved when the following input leads to vomiting:
-Input: Labryinth disorders and motion sickness.

A
  • Input :- Motion and labyrinth disorders
    • Neuroreceptors in the brain stimulated :- AchM and H1
    • Neuronal pathway :- Vestibular system.
    • Projections from vestibular nuclei stimulate the vomiting center.

Note main mechanism:

  • Uses Vestibular projections to the CTZ which stim. the vomiting center.
  • Vomitting center is activated
  • Leading to nausea and vomiting
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Practice: Name the Neuroreceptors and Neural pathway involved when the following input leads to vomiting:
-Input: Drugs, Metabolic products, Bacterial toxins

A
  • Input : Drugs, bacterial toxins, metabolic products.
    • Neuroreceptors in the stimulated : NK1, D2 (central), 5HT3.
    • Neuronal pathway :- Chemoreceptor trigger zone.
    • Projections from vestibular nuclei stimulate the vomiting center.

Note main mechanism:

  • Uses Vestibular projections to the CTZ which stim. the vomiting center.
  • Vomitting center is activated
  • Leading to nausea and vomiting
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

There are 8 groups of anti-emetic drugs, what are they?

A
  1. Antihistamines.
  2. Anticholinergic drugs.
  3. Serotonin antagonist
  4. Dopamine antagonist
  5. Neurokinin antagonist
  6. Corticosteroids
  7. Cannabinoids
  8. Benzodiazepines
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Name 4 anti-histamine drugs that one can admit for nausea and vomiting:

A

Promethazine
Cyclizine
Betahistine
Cinnarizine

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

What cause of nausea and vomiting are anti-histamines most effect against fighting?

A

Motion sickness and labyrinth disorders

- Acts on vestibular efferents and within brain stem

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

What limitations are there to using this drug?

A

Modest efficacy.
Dose related adverse effects.
Antimuscarinic drugs.

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

What is betahistine used for?

A

Used in vertigo

Hearing loss associated with Ménière’s disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is Cinnarizine and where is UGIT used?

A

Anti histamine and calcium antagonist.

Treatment of vertigo Nd motion sickness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Name the 3 types of dopamine antagonists:

A

Phenothiazines
Benzamines
Butyrophenones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Give a few facts about phenothiazines

A

Most common anti-emetics.
- Prochlorperazine
Act on CTZ in small doses and vomit center in high doses.
Helpful in treating hiccups (chlorpromazine)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Which drugs are the least effective in testing motion sickness?

A

Phenothiazines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are the side effects of phenothiazines?

A

Extra- pyramidal S/E, Hypotension and restlessness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Give an example of a benzamine:

A

Metoclopramide.

- Maxolon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How does Metoclopramide work?

A

Promotes gastric emptying due to 5HT4 receptor (serotonin) stim.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

When is Metaclopramide ineffective?

A

Ménière’s disease
Motion sickness and vertigo
Labyrinth disorder

33
Q

What are the adverse effects of metaclopramide?

A
  • Extra-pyramidal symptoms
    • Diarrhea
    • Sedation
34
Q

Where are 5HT3 receptor antagonists usually used?

A

Chemotherapy- induced emesis.

Post operative nausea and vomiting: Alongside anti-histamines

35
Q

Give a few examples of 5HT3 antagonists (end on setron):

A

Ondansetron.
Ganisetron.
Palonsetron.
Dolasetron.

36
Q

Why are serotonin antagonists so effective?

A

5HT3 Antagonists have action at both periphery and central sites.
Peripheral:
- Block 5HT3 visceral vagal afferent fibers
Central sites
- block 5HT3 in CTZ

37
Q

What are some adverse effects of using 5HT3 receptor antagonists?

A

Headaches are most common

Constipation.

38
Q

Name 4 5HT3 receptor antagonist drugs:

A

Ondansetron
Granisetron
Palonsetron
Dolasetron

39
Q

What are Benzodiazepines?

A

These are anti-emetics with a relatively low potency

40
Q

Name 3 side effects of benzodiazepines:

A

Sedative.
Anxiolytic drug.
Amnesic.

41
Q

To enhance the effect of the drug, which drug class is administered alongside a 5HT3 receptor antagonist

A

Corticosteroids

Examples include:

  • Dexamethazone
  • Methylprednisolone.
42
Q

Give an example of a Neurokinin antagonist drug:

A

Aprepitant (Emend)

  • A new class drug targeting the N1 receptors in the brain
  • Blocks substance P in the CTZ vomit center.
43
Q

Name 2 indications of Neurokinin (Aprepitant):

A

Prevention of chemotherapy induced nausea and vomiting

Prevention of postoperative nausea and vomiting.

44
Q

Name 3 adverse effects of Neurokinin antagonist Aprepitant:

A

Extensive metabolism of CYP34A
Constipation and fatigue
Shorten the half life of warfarin

45
Q

Name 2 corticosteroids that can be used as anti-emetics

A

Dexamethasone

Methylprednisolone

46
Q

Which 2 drug groups can corticosteroids-steroids be co-administered with, for an additive effect?

A

5HT3 antagonists

N1 antagonists

47
Q

When would corticosteroids-steroids be used an anti-emetic?

A

Cytotoxic drugs

48
Q

Name 2 cannibinoid anti-emetics:

A

Nabilone

Dronabinol

49
Q

When are canniboids useful?

A

Useful in nausea and vomiting in cytotoxic therapy.

50
Q

What is the mechanism of action for cannabinoids?

A

Block descending pathway in cortical areas.

51
Q

What side effects are associated with cannabinoids?

A 
Hallucinations 
Dysphoria 
Sedation 
Vertigo 
Disorientation.
52
Q

What reaction is expected to be observed in the GIT, when muscarinic receptors are stimulated?

A

Increase GI motility

Increase in secretions.

53
Q

Name the receptor subtype as well as, It’s parasympathetic and sympathetic effect on:

  1. Stomach motility and tone:
  2. Stomach sphincters:
  3. Stomach secretion:
A
  1. Motility and tone:
    Parasympathetic: M2= M3 ~ Increase in contraction.
    Sympathetic: Beta 2 ~Decrease in dilation
  2. Sphincters
    Parasympathetic: M3>M2 ~ Increase in relaxation
    Sympathetic: Alpha 1 ~ Contraction
  3. Secretion:
    Parasympathetic: M3>M2 ~ Increase in stimulation
    Sympathetic: Alpha 2 ~ Inhibition.
54
Q

Name the receptor subtype as well as, It’s parasympathetic and sympathetic effect on:

  1. Intestinal motility and tone:
  2. Intestinal sphincters:
  3. Intestinal secretion:
A
  1. Motility and tone:
    Parasympathetic: M2= M3 ~ Increase in contraction.
    Sympathetic: Beta 2 ~Decrease in dilation
  2. Sphincters
    Parasympathetic: M3>M2 ~ Increase in relaxation
    Sympathetic: Alpha 1 ~ Contraction
  3. Secretion:
    Parasympathetic: M3>M2 ~ Increase in stimulation
    Sympathetic: Alpha 2 ~ Inhibition.
55
Q

Name the receptor subtype as well as, It’s parasympathetic and sympathetic effect on:
1. The gallbladder and bile ducts

A

Parasympathetic: M ~ Increase in Contraction
Sympathetic: Beta 2 ~ Relaxation

56
Q

Name 4 drugs that are classified as an anti-muscarinic anti-emetic:

A

Mebeverine.
Hyoscine butylbromide.
Dicyclomide.
Propantheline.

57
Q

What is Dicyclomide commonly used for?

A

Relief of biliary, intestinal and genitourinary spasms

- Associated with respiratory collapse.

58
Q

What is anti-emetic, propantheline, typically used for?

A

Peptic ulcer disease

- Associated with inhibition of sweating.

59
Q

What is the anti-emetic, Hyoscine butyl-bromide, typically used for?

A

Anti-spasmodic

60
Q

What is the anti-emetic, Mebeverine typically used for?

A

Selective spasmolytic on GI

Most effective on sphincter of Oddi

61
Q

What is the mechanism of diarrhea:

A
  1. Increase in osmotic load in intestine= retention of water in the lumen.
  2. Excessive secretion of electrolytes and water.
  3. Disrupted intestinal motility = Rapid transit and dec. fluid absorption.
  4. Exudation of protein and fluid from the mucosa.
62
Q

What is the treatment goal of anti-diarrheal agents?

A

Anti-infective agents.
Restore electrolyte imbalance and prevent dehydration.
Use of spasmolytics

63
Q

Anti-diarrheal agents fall into 1 of 4 categories depending on their mechanism of action . What are these categories?

A

Anti-motility.
Modify fluid and electrolyte transport.
Absorbent.
Probiotics.

64
Q

Name 3 anti-motility agents

A

Loperamide
Diohenoxylate
Codeine

65
Q

Name 3 adverse effects of anti-motility drugs:

A

Constipation
Drowsiness
Abdominal cramps

66
Q

Where should anti-motilities be avoided?

A

Avoid in patients with suspected inflammatory diarrhea

- Toxic mega colon in patients with C. difficile

67
Q

What is Bismuth Subsalicylate?

A

Anti-diarrheal agent

- Modifies fluid and electrolyte transport

68
Q

Where is Bismusth subsalicylate indicated?

A

-Travellers diarrhea

69
Q

Side effects of Bismuth Subsalicylate?

A
  • Black discoloration of mucous membranes
70
Q

What are 4 kinds of absorbents?

A

Bile acid sequestrats
Kaolin and pectin
Methylcellulose
Aluminum hydroxide

71
Q

What is the mechanism of action for absorbents?

A

Absorb intestinal toxins or micro-organisms

Coat/protect intestinal mucosa

72
Q

Hat is the mechanism of action for probiotics?

A

Contain a variety of bacteria strains that help in

  • Antibiotic related diarrhea
  • Acute diarrhea
  • Infectious diarrhea
73
Q

What are laxatives?

What are 4 types of laxatives

A

Supplements that accelerate transit time through intestines.
Types include:
- Dietry fiber and supplements (Bulk laxatives)
- Stool wetting and emollients laxative
- Osmotic active laxative
- Irritant laxative

74
Q

Name 2 risks of chronic laxative use:

A
  • Habit forming.

- Electrolyte imbalance if use chronically

75
Q

What is the mechanism of action of dietary fibre laxatives?

A

Unfermented fibre attracts water and increases stool bulk.

  • Forms a gel that retains water.
  • And distends intestine which increases peristalsis.
76
Q

What are the contra-indications of dietary supplement laxatives?

A

Megacolon.

Megarectum.

77
Q

Name 3 types of osmotic agents that are working laxatives

A
  1. Saline laxatives
  2. Electrolyte solution laxatives
  3. Non-digestible sugars
    • Lactulose.
    • Cannot be hydrolyzed by intestinal enzymes.
    • Degraded into lactic acid, formic and acetic acid.
    • Increase osmotic pressure.
    • Increase lumen, increase fluid, increase diarrhea.
78
Q

What stool emollient leads to anal leakage?

A

Mineral oils

Surgery- UGIT (2) (6 decks)

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