pharmacology of nausea and vomiting

Question 1

how is vomiting induced

Answer 1

toxic materials and toxins stimulate enterochromaffin cells in the mucosa which release mediators eg serotonin.
there is depolarisation of sensory afferent terminals in the mucosa and AP discharge in vagal afferents to brainstem

Question 2

what are the sphincters like during vomiting

Answer 2

relaxed

Question 3

name 3 prodromal signs

Answer 3

skin - pallor and cold sweat
heart - inc rate and force
salivary glands - inc secretion

Question 4

what effect does vomiting have on K

Answer 4

hypokalaemia

Question 5

how do dopamine antagonists work

Answer 5

block the CTZ

Question 6

what are dopamine antagonists used for

Answer 6

associated radiation sickness, drug induced emesis and neoplastic disease

Question 7

how are dopamine antagonists available

Answer 7

rectal suppositories and buccal

Question 8

name 2 prokinetic drugs

Answer 8

metoclopramide and domperidone

Question 9

what is metoclopramide also used in

Answer 9

migraine - inc the absorption of other drugs

Question 10

what does domperidone not cross

Answer 10

the BBB

Question 11

what are 5HT3 antagonists used in

Answer 11

CINV, radiation induced and PONV

Question 12

what is a side effect of 5HT3 antagonists

Answer 12

headache

Question 13

what are H1 antihistamines used in

Answer 13

motion sickness, morning sickness and PONV

Question 14

what is cinnarzine also used for

Answer 14

additional antivertigo action inhibiting calcium influx & suppressing labyrinthine reflexes, thus helping in tinnitus and Ménière’s disease.

Question 15

anticholingerics

Answer 15

hyoscine and dicyclomine

Question 16

how can anticholingerics be used

Answer 16

transdermal patch, oral, IM

Question 17

what are the side effects of anticholingerics

Answer 17

blurred vision, urinary retention, dry mouth and sedation

Question 18

what are anticholingerics used in

Answer 18

motion sickness

Question 19

what is the triple drug regime used in CINV

Answer 19

5HT3 receptor antagonist and dexamethasone and aprepitant

Question 20

what is dexamethasone

Answer 20

corticosteroid

Question 21

acute CINV

Answer 21

pretreatment with dexamethasone, lorazepam and triple regime

Question 22

delayed CINV

Answer 22

triple regime and metoclopramide

Question 23

anticipatory CINV

Answer 23

lorazepam

Question 24

what are some non pharmacological treatment s for pregnancy associated nausea and vomiting

Answer 24

changes in diet 
ginger or pyridoxine 
wrist acupressure (P6)

Question 25

what is Hyperemesis gravidarum

Answer 25

fluid and electrolyte disturbances or nutritional deficiency that develops from intractable vomiting in pregnancy.

Question 26

first line for Hyperemesis gravidarum

Answer 26

antihistamine - promethazine or cyclizine

Question 27

second line for Hyperemesis gravidarum

Answer 27

prochlorperazine and metoclopramide.

Question 28

what is the gastroileal reflex stimulated by

Answer 28

gastric distension

Question 29

what does the gastroileal reflex involve

Answer 29

opening of the ileocaecal valve

Question 30

what does teh large intestine secrete

Answer 30

K, HCO3 and mucus

Question 31

what is haustration

Answer 31

Non propulsive segementation caused by contraction of the circular muscle

Question 32

what does haustration allo

Answer 32

time for fluid and electrolyte reabsorption

Question 33

what is the role of the colonic flora

Answer 33

promote motility and help maintain mucosal integrity synthesise vitamin K2 and free fatty acids (from carbohydrate) that are absorbed activate some drugs

Question 34

what is Sulfasalazine

Answer 34

5-ASA linked to sulfapyridine by an azo bond

Question 35

how does Sulfasalazine work

Answer 35

reduces inflammation by inhibiting COX and LOX

Question 36

Sulfasalazine AE

Answer 36

include rashes, arthralgias, blood dyscrasias

Question 37

what are Sulfasalazine AE due to

Answer 37

absorbed sulfapyridine

Question 38

what is advised durin the use of Sulfasalazine

Answer 38

folic acid

Question 39

what is better tolerated than Sulfasalazine

Answer 39

mesalazine

Question 40

what is balsalazide

Answer 40

a prodrug

Question 41

how do IS work

Answer 41

inhibit T lymphocyte function

Question 42

what is the AE of ciclosprin

Answer 42

renal toxicity

Question 43

what is 6-Mercaptopurine

Answer 43

a metabolite of azathioprine

Question 44

what is 6-Mercaptopurine | used for

Answer 44

maintenance of remission of IBD

Question 45

what is given in IBS

Answer 45

antispasmodic laxative antimotility antidepressant

Question 46

what is the first line antimotility in IBS

Answer 46

loperamide

Question 47

what laxative would you not give in IBS

Answer 47

lactulose

Question 48

what is the value of antispasmodics in IBS

Answer 48

relieve cramps

Question 49

what are some direct SM relaxants

Answer 49

Alverine, mebeverine, peppermint oil

Question 50

what is the effect of antidepressants in IBS

Answer 50

prevent afferents from GIT/reduce pain perceptions

Question 51

name some selective serotonin uptake inhibitors

Answer 51

Citalopram, Fluoxetine, Paroxetine

Question 52

what is diarrhoea defined as

Answer 52

loss of fluid and solutes from the GI tract > 500ml per day