10.2 N+V, constipation, diarrhoea

Question 1

define emesis

Answer 1

involuntary, forceful expulsion of gastric contents through mouth

Question 2

stages of vomiting

Answer 2

deep breath
glottis closes
abdo muscles contract
LOS relaxes
retrograde peristalsis of small bowel

Question 3

3 relevant strctures to vomiting found in medulla

Answer 3

vestibular nuclei- input from labyrinth
vomiting centre- cooridnates
CTZ- senses emetic stimuli

Question 4

receptors of vomiting centre

Answer 4

NK1
ACh muscarinic
histamine 1
5HT2

Question 5

receptors in motion sickness

Answer 5

ACh muscarinic
H1

Question 6

SEs of muscarinic antagonists

Answer 6

constipartion, dizziness, dry mouth, confusion, blurred vision

Question 7

contraindications of muscarinic antagonists

Answer 7

elderly
glaucoma

Question 8

H1 antagonist action

Answer 8

inhibits histaminergic signals from vesitublaer system to CTZ

Question 9

ADRs for H1 antagonist

Answer 9

same as anti muscarinic

Question 10

contraindications for H1 antagonist

Answer 10

epilepsy
glaucoma
children
elderly

Question 11

practical methods for motion sickness

Answer 11

position in car
hydration
distraction

Question 12

2 drugs used for motion sickness

Answer 12

1. anti muscarinics e.g. hyoscine
2. anti histamines e.g. cinnazarine

Question 13

metoclopramide
-drug class
-uses
-ADRs

Answer 13

-D2 receptor antagonist
-surgery, chemo
-depression, diarrhoea, drowsiness

Question 14

domperidone
-drug class
-uses
-ADRs

Answer 14

-D2 receptor antagonist
-antiemetic, improve location, palliative care
-long QT and VT, galactorrhea

Question 15

how to NK1 receptor antagonists work?

Answer 15

prevent action of substance P at CTZ and peripheral nerves

Question 16

aprepitant
-drug class
-uses
-ADRs

Answer 16

-NK1 receptor antagonists
-chemo delayed emesis
-constipation, headache

Question 17

what could be used to help pregnancy induced vomiting?

Answer 17

fluids
antihistamines
steroids
metroclopramide, dopimeridone
thiamine replacement

Question 18

benefits of thiamine replacement in pregnancy

Answer 18

fetus brain development
protect mum from wernickes encephalopathy

Question 19

2 ways gut problems can induce vomiting

Answer 19

1. extends bowel wall, stimulates vagus nerve which then stimulates vomiting centre
2. toxins stimulates vomiting

Question 20

ondansetron
-drug class
-uses
-ADRs

Answer 20

-5HT3 antagonist
-antiemtic for chemo, surgery
-constipation, headache

Question 21

management of bowel obstruction

Answer 21

NG tube
treat cause
cyclizine

Question 22

contradictions for bulk forming laxatives

Answer 22

opioid induced constipation- as already so packed

Question 23

how do stimulant laxatives work?

Answer 23

increase electrolytes and water secretion by mucosa, increase peristalsis

Question 24

drugs to treat diarrhoea

Answer 24

opioids
muscarinic receptor antagonists

Question 25

how does loperamide work?

Answer 25

specific to mu receptors in. myenteric plexus of gut, reduces peristalsis