Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

CPT > Nausea, vomiting and diarrhoea > Flashcards

Nausea, vomiting and diarrhoea Flashcards

(78 cards)

Start Studying
1
Q

What actually happens in vomiting?

A
  • Co-ordinated by the vomiting centre in the medulla
  • Take a deep breath
  • Glottis closes
  • Abdominal muscles contract
  • Lower oesophageal sphincter relaxes
  • Retrograde peristalsis of small bowels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the inputs to the vomiting centre?

A
  • Higher cortical centres - pain, repulsive sights and smells, emotional factors
  • CTZ - main site for sensing emetic stimuli (receives input from the vestibular nuclei)
  • Vagal afferents convey signals from gut to brainstem
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What do we target to treat motion sickness?

A
  • Muscarinic ACh receptors
  • H1
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Give some examples of muscarinic antagonist drugs?

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

What is the mechanism of action of muscarinic antagonists?

A
  • Competitive blockade of muscarinic acetylcholine receptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the adverse side effects of anti-muscarinics?

A
  • Sedation
  • Constipation
  • Dizziness
  • Dry mouth
  • Visual problems
  • Confusion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the contraindications of anti-muscarinic drugs?

A
  • Elderly patients
  • Glaucoma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the DDIs of anti-muscarinic drugs?

A
  • Anti-psychotic medication
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Give some examples of H1 antagonists?

A
  • Cyclizine
  • Levomepromazine
  • Prochlorperazine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How do H1 antagonists work?

A
  • Works centrally
  • Acts on the vomiting centre and vestibular nuclei
  • Inhibits histaminergic signals from the vestibular system to the CTZ in the medulla
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the adverse side effects of H1 antagonists?

A
  • Sedation
  • Anti-muscarinic side effects e.g. dry mouth, constipation, urinary retention, blurred vision
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the contraindications of H1 antagonists?

A
  • Epilepsy
  • Glaucoma
  • Urinary retention
  • Children
  • Elderly patients
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which H1 antagonists are sedating?

A
  • Diphenhydramine (Benadryl)
  • Promethazine
  • Chlorphenamine
  • Cinnarizine
  • Cyclizine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which H1 antagonists are non sedating?

A
  • Cetirizine
  • Fexofenadine
  • Loratidine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Outline the epidemiology of motion sickness?

A
  • Very common
  • Affects women more than men
  • Affects children more than adults
  • People who have migraine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the practical methods of motion sickness prevention?

A
  • Hydration
  • Position in the vehicle
  • Distraction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the drugs used to treat motion sickness?

A
  • Anti-muscarinics - hyoscine (scopolamine)
  • Anti-histamines - cinnarizine, cyclizine, prochlorperazine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which drugs can make a patient feel nauseous?

A
  • Chemotherapy
  • Opioids
  • General anaesthetics
  • Digoxin
  • NSAIDs
  • Diuretics
  • Antibiotics
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Which metabolites can cause nausea?

A
  • Uraemia
  • DKA
  • Addison’s disease
  • Hyperthyroidism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Which toxins can cause nausea?

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

Give some examples of D2 receptor antagonists

A
  • Metoclopramide
  • Domperidone
  • Haloperidol
  • Prochlorperazine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Outline the mechanism of action of metoclopramide

A
  • Central dopamine antagonist
  • Peripheral cholinergic agonist
  • Increases acetylcholine at muscarinic receptors in the gut
  • Promotes gastric emptying
  • Increases tone at lower oesophageal sphincter
  • Increases tone and amplitude of gastric contractions
  • Decreases tone of pylorus so it opens
  • Increases peristalsis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the adverse side effects of metoclopramide?

A
  • Depression
  • Diarrhoea
  • Drowsiness
  • Hypotension
  • Galactorrhoea
  • Extra-pyramidal effects e.g. dystonia, parkinsonism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the contraindications of metoclopramide?

A
  • Post-GI surgery
  • GI obstruction
  • GI perforation
  • GI haemorrhage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
How does domperidone work?
- Similar mechanism to metoclopramide - Good for improving lactation in breastfeeding mothers
26
Why is domperidone not used as frequently anymore?
- Increased risk of cardiac side effects
27
What are the adverse side effects of domperidone?
- Dry mouth - Long QT interval - Ventricular tachycardia - Galactorrhoea - Loss of libido
28
What are the contraindications of domperidone?
- Patients >60 years old
29
What is the mechanism of action of haloperidol?
- Act on the CTZ
30
What are the adverse side effects of haloperidol?
- Parkinsonism - Movement disorder - Long QT - Arrhythmia - Constipation - Dry mouth
31
What are the contraindications of haloperidol?
- Parkinson's disease - Cardiovascular disease - Diabetes - Myasthenia gravis
32
What is the mechanism of action of the 'zines'?
- Act on the CTZ - May also block H1 and muscarinic receptors
33
What are the adverse side effects of the 'zines'?
- Drowsiness - Dry mouth - Movement disorder - Parkinsonism - Long QT - Urinary retention
34
What are the contraindications of the 'zines'?
- Elderly patient - Parkinson's disease - Cardiovascular disease - Diabetes - Myasthenia gravis
35
What are some examples of NK-1 receptor antagonists?
- Aprepitant - Fosaprepitant - Netupitant
36
What is the mechanism of action of NK-1 receptor antagonists?
- Prevent the action of substance P at CTZ and in peripheral nerves - Boosts effects of 5HT3 receptor antagonists - Anxiolytic and antidepressant properties - Good for chemotherapy - particularly for delayed emesis
37
What are the adverse side effects of NK-1 receptor antagonists?
- Constipation - Headache - Asthenia
38
What are the contraindications of NK-1 receptor antagonists?
- Acute porphyrias
39
What is the mechanism of action of corticosteroids?
- Assumed to act on the CTZ - May also have properties of D2 receptor antagonists
40
What are corticosteroids good for treating?
- Perioperative nausea and vomiting - Chemotherapy - Palliation
41
What are the adverse side effects of corticosteroids?
- Insomnia - Osteoporosis - Increased weight - Increased appetite - Increased blood sugar - Cushing's syndrome
42
What are the contraindications of corticosteroids?
- Osteoporosis - Diabetes mellitus - Peptic ulcer
43
What are some examples of corticosteroids?
- Dexamethasone - Methylprednisolone
44
What is the mechanism of action of cannabinoids?
- Assumed to act on the CTZ - Good for chemotherapy - used as last line
45
What are the adverse side effects of cannabinoids?
- Confusion - Depression - Drowsiness - Dizziness - Movement disorders - Psychosis - Tremor - Visual impairment
46
What are the contraindications of cannabinoids?
- Elderly patients - Heart disease - History of psychiatric disorder
47
Give an example of a cannabinoid?
- Nabilone
48
What can cause post-operative vomiting?
- Operation itself - General anaesthesia/post-operative medications - Predisposing factors - Metabolic causes - uraemia, diabetic ketoacidosis, hypercalcaemia - Ileus - Bowel obstruction
49
Which drugs are used to treat post-operative vomiting?
- Metoclopramide - Prokinetics - Hyoscine (reduces secretions)
50
Which drugs are used to treat pregnancy-induced vomiting?
- Fluid replacement - Anti-histamines - promethazine/cyclizine - Phenothiazine or prochlorperazine - Ondansetron - Steroids - Metoclopramide and domperidone - Thiamine replacement
51
Which drugs are used to treat chemotherapy-induced nausea and vomiting?
- 5-HT3 antagonists e.g. ondansetron cover the acute emetic stimulus of chemotherapy administration only - Aprepitant can have a positive effect on delayed nausea and vomiting - Dopamine antagonists e.g. metoclopramide are more effective for delayed nausea +/- dexamethosone - Lorazepam or other anxiolytic treatment can help anticipatory nausea or vomiting
52
Give an example of a 5-HT3 antagonist
- Ondansetron - Granisetron - Palonosetron
53
What is the mechanism of action of ondansetron?
- Reduces GI motility and secretions - Acts to inhibit CTZ - Prevents excit
54
What are the adverse side effects of 5-HT3 antagonists?
- Constipation - Headache - Elevated liver enzymes - Long QT syndrome - Extra-pyramidal effects - Dystonia - Parkinsonism
55
What are the contraindications of 5-HT3 antagonists?
- Subacute abdominal obstruction - Susceptible to long QT
56
What are the non-pharmacological options for treating bowel obstruction?
- NG tube
57
Which drugs are used to treat bowel obstruction?
- Cyclizine used 1st line
58
How do we treat constipation without medicine?
- Healthy diet - dietary fibre intake - Fluid intake - Exercise - Toilet routine and positioning
59
What are some examples of bulk-forming laxatives?
- Ispaghula husk - Methylcellulose
60
What is the mechanism of action of bulk-forming laxatives?
- Polysaccharide polymers that are not digested in the upper part of the GI tract - Forms a bulky hydrated mass in the gut lumen promoting peristalsis and improving faecal consistency
61
Give some examples of faecal softeners
- Docusate sodium - Arachis oil enema - Liquid paraffin
62
What is the mechanism of action of faecal softeners?
- Acts in the GI tract in a manner similar to a detergent and produces softer faeces - It is also a weak stimulant laxative
63
Give some examples of osmotic laxatives?
- Lactulose - Macrogol
64
What is the mechanism of action of osmotic laxatives?
- Poorly absorbed in the gut - Lactulose: semisynthetic disaccharide of fructose and galactose - Macrogol: inert ethylene glycol polymers
65
What are the adverse side effects of osmotic laxatives?
- Flatulence - Cramps - Diarrhoea - Electrolyte disturbance
66
Give some examples of stimulant laxatives
- Bisacodyl - Sodium picosulfate - Senna - Glycerol suppositories
67
What are the side effects of stimulant laxatives?
- Abdominal cramps - Nausea - Rash
68
What are the contraindications of stimulant laxatives?
- Diarrhoea - Bowel obstruction
69
What causes diarrhoea?
- Drugs - Infection - Toxins/drugs - Radiotherapy - Anxiety
70
Which drugs cause diarrhoea?
- Domperidone (increases GI motility - mechanism unknown) - Metoclopramide (increases gastric emptying and motility) - Naloxegol - (M opioid receptor antagonist)
71
How do we treat diarrhoea?
- Treat the complication - Treat the cause - Reduce bowel motility/increase transit time - For comfort and prevent incontinence
72
How do we treat the complication of diarrhoea?
- Oral rehydration - IV fluids
73
What are some drugs that treat diarrhoea?
- Opioids: codeine, loperamide - Muscarinic antagonists
74
What is the mechanism of action of loperamide?
- Decreases tone of longitudinal and circular smooth muscle - Reduces peristalsis but increases segmental contractions - Decreases colonic mass movement by suppressing gastrocolic reflex
75
What do opioids target?
- M and D receptors?
76
What are the adverse side effects of opioids?
- Paralytic ileus - Constipation - Nausea and vomiting - Reduced respiratory rate - Sedation - Addiction/withdrawal syndrome
77
What are the contraindications of opioids?
- Impaired respiratory function - Adrenocortical insufficiency - Elderly patients
78
What are the adverse side effects of loperamide?
- Headache - Nausea - Drowsiness - Dizziness - Dry mouth

CPT (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions