Antiemetics and antidiarrhoeals

Question 1

Ondanstron

Answer 1

Reduces gut mobility and and reduces gi secretions and acts to inhibit ctz good for everyone but can cause constipation headache and elevated liver enzymes

Question 2

Metaclopramide

Answer 2

D2 receptor agonist
Increases ACH at mucscarinic receptors
Promote gastric emptying by increaseing the tone of the lower oesophageal sphincter and increaseing gastric contractions
Good for good and ileum

Side effects - galactorrhoea - as it can not antagonises prolactin release.

Question 3

Domperidome

Answer 3

D2 receptor antagonists
Promotes gastric emptying increasing gastric contractions

Good for improving lactation in breast feeding mothers

Side effects sudden cardiac death and galactorrhea

Question 4

Hyosine hydrobromide

Answer 4

Complete blockage of muscularinic acetylene choline receptors in the vestibular nuclei. Also works on the CTZ
Good for motion sickness and bowel obstruction
Side effects - sedation memory problem glaucoma, dry mouth and constipation

Question 5

Haloperidol

Answer 5

Acts as a D2 receptor antagonist
Acts on the CTZ
Good for chemotherapy and Palliation
It is an antipsychotic and is there for used for agitated patients.
Side effects - extra pyramidal effects, sedation, hypotension

Question 6

DEXAMETHASONE

Answer 6

Corticosteroid
- acts on the CTZ may also have
- may also have properties of D2 receptor antagonists
Good for :- peri-operative nausea and vomiting chemo and palliation
Side effects - insomnia increased appetite and increase blood sugar

Question 7

Prochlorperazine

Answer 7

D2 receptor antagonists

Used in morning sickness in pregnancy

Question 8

Methylprednisolone

Answer 8

Corticosteroid
- acts on the CTZ may also have
- may also have properties of D2 receptor antagonists
Good for :- peri-operative nausea and vomiting chemo and palliation
Side effects - insomnia increased appetite and increase blood sugar

Question 9

Nabilone

Answer 9

Cannabinoids

Last resort

Question 10

Aprepitant

Answer 10

Neurokinin 1 receptor antagonists
Prevents the action of substance P at the CTZ and in peripheral nerves.
Boosts effects of 5HT receptor antagonists which decrease gut motility and secretions
Good for (also good for pain control) chemotherapy - especially delayed emesis (vomiting )
Side effects :- head ache, diarrhoea/constipation, Steven Johnson syndrome ( severe skin reaction )

Question 11

What is the best drugs to treat motion sickness

Answer 11

Hyosine hydrobromide is 1st lien

Question 12

What drug would you use to stop vomiting in gastroenteritis

Answer 12

Trick question you wouldn’t want to stop the vomiting as it is a normal response to stop infection

Question 13

What is useful in the treatment of GORD and or Ileus

Answer 13

Domperidone - 2nd line one
Metaclopramide

Both are a D2 receptor antagonists

Question 14

What would you not use for vomiting with obstruction

Answer 14

DO NOT GIVE PROKINETICS

As there is a risk of perforation due to increased pressure

Question 15

What would you use for gut pathologies to stop emesis when it is non infective

Answer 15

Ondansetron 5HT3 receptor antagonist 
And/or 
Cyclizine H1 receptor antagonist 
And then add 
DEXAMETHASONE corticosteroid

Question 16

What is the treatment for hyperemesis gravidarum

Answer 16

Promethazine (H1 receptor antagonist ) 
Or 
Prochlorperazine (D2 receptor antagonist) 
Then add 
Metaclopramide (D2 receptor antagonist) 
Then add 
Ondansetron (5HT3 receptor antagonist)

Question 17

Loperamide

Answer 17

Opioid receptor agonist
Specific the mop receptors in the myenteric plexus
- it decreases tone of longitudinal and circular smooth muscle
-