Brainscape's Knowledge GenomeTM

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


See full index

MD3002 WEEK 4 - B > 1. Treatment of Vomiting & Gut Motility Disorders > Flashcards

1. Treatment of Vomiting & Gut Motility Disorders Flashcards

1
Q

What are the two units of vomiting neural control?

A

Central neural regulation of vomiting is controlled by 2
separate units both in the medulla:
1) The Vomiting centre
2) The Chemoreceptor Trigger Zone, CTZ

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

List the types of drugs which may be used to modify the emetic response and gut motility

A
  • Antihistamines
  • Antimuscarinics
  • Dopamine antagonists
  • 5HT3 antagonists
  • Neurokinin 1 receptor antagonists
  • Synthetic cannabinoids
  • Steroids
  • Other neuroleptics
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Vestibular labyrinth –> ______ ____ (____ ____) –> cerebellum –> ____ –> vomiting centre —> vomit

A

Vestibular labyrinth –> Vestibular nuclei (brain stem) —->cerebellum –> CTZ –> vomiting centre —> vomit

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

Vestibular labyrinth –> ______ ____ (____ ____) –> cerebellum –> ____ –> vomiting centre —> vomit

A

Vestibular labyrinth –> Vestibular nuclei (brain stem) —->cerebellum –> CTZ –> vomiting centre —> vomit

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

What is the difference between nausea, retching and vomiting?

A

Nausea: Feeling of wanting to vomit

  • Associated with autonomic effects: salivation / pallor / sweating
  • Often prodrome of vomiting

Retching: Strong involuntary effort to vomit, Unproductive

Vomiting: Expulsion of gastric contents through the mouth

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

Triggers for vomiting/nausea

A
  • Stimulation of the sensory nerve endings in the stomach and duodenum.
  • Stimulation of the vagal sensory endings in the pharynx.
  • Drugs or endogenous emetic substances.
  • Disturbances of the vestibular apparatus.
  • Various stimuli of the sensory nerves of the heart and viscera.
  • A rise in intracranial pressure.
  • Nauseating smells, repulsive sights, emotional factors.
  • Endocrine factors
  • Migraine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

3 types of vomiting and the difference between them?

A
  1. Projectile vomiting
    Suggestive of gastric outlet or upper GI obstruction
  2. Haematemesis
    Vomiting fresh or altered blood (“coffee- grounds”) e.g. oesophageal varices, bleeding gastric ulcer
  3. Early-morning
    e. g. pregnancy, alcohol dependence, some metabolic disorders (uraemia)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How do antihistamines act as anti-emetics? Name 3 examples. Side effects?

A

• H1 histamine receptor antagonists
• Useful in numerous causes of N/V; including
motion sickness + vestibular disorders
• Side-effect profiles vary e.g. drowsiness and antimuscarinic effects

Examples:

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

How do antimuscarinics act as anti-emetics? Name an example. Side effects?

A

Muscarinic receptor antagonists
Mechanism: Blockade of muscarinic receptor-mediated impulses from the labyrinth and from visceral afferents
Example: Hyoscine hydrobromide
Side effects: Constipation, transient bradycardia, dry mouth

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

How do dopamine antagonists act as anti-emetics? Name 3 examples

A 
Mechanism: Act centrally as dopamine antagonists on the CTZ. Active against CTZ-triggered vomiting but not stomach-induced vomiting.
Examples:
1. Phenothiazines e.g. chloropromazine
2. Domperidone
3. Metoclopramide
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How do 5HT3 antagonists act as anti-emetics? Name 4 examples

A

Block 5HT3 receptors in GIT and in the CNS. Particularly useful in managing N/V in patients receiving cytotoxic and postoperative N/V

Examples:

  1. Dolasetron
  2. Granisetron
  3. Ondansetron
  4. Palonosetron
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How do neurokinin 1 receptor antagonists act as an anti-emetic? 2 examples?

A

Adjunct to dexamethasone and a 5HT3 antagonist in preventing N/V associated with chemotherapy

Examples: Aprepitant, fosaprepitant

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

How do synthetic cannabinoids act as anti-emetics? Name an example

A

Used for N/V caused by chemo unresponsive to conventional anti-emetics
Side effects: Drowsiness/ dizziness

Example: Nabilone

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

Use of steroids as anti-emetics? Example?

A

Used alone, to treat vomiting associated with cancer chemotherapy or in conjunction with other antiemetics
Example: Dexamethasone

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

Name 2 other neuroleptics used to treat emesis?

A

Haloperidol

Levomepromazine

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

Before prescribing laxatives, what 3 steps must be taken?

A
  1. Ensure the problem is constipation
  2. Check the patient’s “norm”
  3. Try to reverse the cause, including diet.lifestyle changes
17
Q

What are the 5 types of laxatives?

A
  1. Bulk-forming laxatives
  2. Stimulant laxatives
  3. Faecal softeners
  4. Osmotic laxatives
  5. Peripheral opioid-receptor antagonists
18
Q

How do laxatives work?

A

Bulk fibre provides increased volume and promotes peristalsis by distension
Some laxatives soften stool by coating and breaking up particles
Liquid mixes with stool to soften

19
Q

Name examples of the following types of laxatives:
Bulk (2)
Stimulate (6)
Softener (2)
Osmotic (4)
Peripheral opioid receptor antagonist (1)

A

Bulk: Ispaghula husk, methylcellulose
Stimulant: bisacodyl, dantron, docusate sodium, glycerol, senna, sodium picosulfate
Softener: arachis oil, liquid paraffin
Osmotic: lactulose, macrogols, magnesium salts, rectal phosphates
Peripheral opioid receptor antagonist: methylnaltrexone bromide

20
Q

What two properties of diarrhoea lead to loss of electrolytes?

A

Increase in the motility of the GIT

Decrease in the absorption of fluid

21
Q

4 approaches to treating ACUTE diarrhoea?

A
  1. Maintenance of fluid and electrolyte balance e.g. oral rehydration preparation
  2. Antimotilty drugs
  3. Antispasmodics e..g. hyoscine hutylbromide (buscopan), mebeverine
  4. Antibacterial agent is indicated e.g. systemic bacterial infection, campylobacter enteritis, shigellosis and salmonellosis
22
Q

What 3 agents are used to treat chronic diarrhoea?

Name at least 2 examples for each

A

Antimotility agents:

  • Codeine
  • Co-phenotrope
  • Loperamide (Imodium)
  • Morphine

Adsorbents:

  • *Not for acute diarrhoea**
  • Kaolin
  • Light

Bulk forming drugs:

  • Useful in controlling diarrhoea associated with diverticular disease
  • Ispaghula
  • Methycellulose
  • Sterculia
23
Q

5 components of bile?

A 
Bile salts
Bilirubin
Cholesterol
Lecithin
Plasma electrolytes
24
Q

Which hormone stimulates gallbladder emptying?

A

Cholecystokinin (CCK)

25
Q

Treatment of gallstones?

A
  1. Lap Chole

2. Ursodeoxycholic acid to dissolve gallstones

26
Q

Treatment of biliary colic and acute cholecystitis?

A

Biliary colic:

  • V painful so may require morphine / pethidine (opioids) or diclofenac (NSAID) by suppository
  • Parenteral/rectal route chosen as overcomes difficulties in absorption caused by vomiting

If pain continues for 24hrs+ or accompanied by fever = HOSPITAL ADMISSION

27
Q

Bile acid sequestrates:
Main example?
Mechanism?
Uses?

A

Main example: Colestyramine (an anion-exchange resin)
Mechanism: Froms an insoluble complex with bile acids in the intestine
Uses:
- Relives pruritus associated with partial biliary obstruction and primary biliary cirrhosis
-Diarrhoea episodes e.g. Crohn’s disease cirrhosis
-Hypercholesterolaemia

28
Q

What is Cholestyramine and it’s uses?

A

A bile acid sequestrant.
It works by helping the body remove bile acids, which can lower cholesterol levels in the blood. The medicine is also used to relieve itching that’s caused by a bile duct blockage.

MD3002 WEEK 4 - B (9 decks)

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