diarrhoea and vomittin

Question 1

causes of diarrhoea

Answer 1

osmotic - an excess of non absorbable substances in the lumen, these substances have an osmotic affect and they hold water in the lumen of the gut.

maldigestion- inability to digest luminal contents

secretory - abnormal ion transport in mucosal epithelium due to altered ion channel function, this leads to fluid secretion into lumen of gut

inflammatory - COME BCAK

Question 2

what’s the difference between osmotic diarrhoea and secretory diarrhoea

Answer 2

osmotic diarrhoea has a larger volume of plasma like fluid and secretory diarrhoea is usually responds poorly to diet changes

Question 3

what are the classifications for diarrhoea

Answer 3

acute - sudden onset lasts for 3 days to 1-2 weeks,

chronic - lasts more than 3-4 weeks with recurring passages of diarrhoea stools, fever and anorexia

Question 4

drug treatments - opiods

Answer 4

• these area the first one treatment
  they are the most effective
  they decrease the intestinal motility, slows intestinal transit which then allows time for absorption of fluids and electrolytes

example - loperamide (imodium)

Question 5

what are other treatments for vomiting

Answer 5

• rehydration salts, this stimulates SGLT pathway in the gut
• racecadotril - this is lioscenced as an adjunct to rehydration for the symptomatic treatment or uncomplicated acute diarrhoea in adults and children over 3 months

Question 6

what are te important neurotransmitters involved in the process of vomiting

Answer 6

• serotonin ( 5-HT3)
• dopamine (D2)
• acetylcholine (m)
• histamine (H1)
• substance p (NK1)

the activation of these receptors by their neurotransmitters causes vomiting and these are prevented by antagonist which are used to prevent these from being activated

Question 7

5 - HT3 receptor antagonists

Answer 7

• they usually end in SETRON
• MOA = they block the 5-HT3 receptor in the gut and CTZ]
• they are the first choice for preventing and treating severe vomiting
• ## they are used to treat acute phase of chemotherapy vomiting

Question 8

neurokinin receptor NK1 antagonist

Answer 8

nk receptors are stimulated by substance p
the antagonist ( eg = APREPITANT) blocks the nk receptors located in CTZ
it is lisceneced for chemo induced emesis especially delayed emesis
and it is usually used with 5-HT3 receptor antagonist

Question 9

glucocorticoids

Answer 9

• they are used in chemo induced vomiting
  often used with with 5-HT3 receptor clockers or NK1 blockers
  there are severe side effects with long term use

Question 10

dopamine receptor d2 antagonist

Answer 10

• the d2 receptors have been found to be the most active during vomiting
  the two main classes of dopamine receptor antagonists for treating vomiting are
• prokinetic drugs
• neuroleptics

they both bock D2 receptors peripherally (in GIT) or centrally or both

Question 11

prokinetic drugs

Answer 11

act peripherally - to exert a prokinetic action on the oesophagus, stomach and intestine

act centrally - to block the dopamine receptors in the ctz

these drugs are used to treat vomiting in gi disorders
and vomiting induced by toxins

Question 12

neuroleptics

Answer 12

• they act centrally to block dopamine receptors in CTZ , they also block muscarnic and histamine receptors

theses rea used to treat severe drug induced nausea and vomiting
PONV

however the side effects are dyskinesia

Question 13

anticholinergic

Answer 13

these work by blocking muscarnicv receptors at the multiple sites in vomiting pathway
usually used to treat motion sickness

side effects - it causes blockade of the parasympathetic nervous system

Question 14

antihistamines

motion sickness

Answer 14

this works by blocking the H1 histamine receptors
used for treatment of motion sickness
promethazine also used in treatment of severe morning sickness

this causes sides effects of CNS depression and sedation, drowsiness and may affect performance of skilled tasks

Question 15

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