Lecture 17/18 - GI medications Flashcards Preview

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Flashcards in Lecture 17/18 - GI medications Deck (83):
1

What is responsible for protecting the stomach from acidic conditions?

Bicarbonate + Mucous

2

When do ulcers occur, most basic mechanism?

Acid > Protective layer

3

What can cause ulcers?

Drugs = NSAIDs + Corticosteroids
H.pylori
Mast cell tumors
GI diseases
Long interavals of no food in horses

4

What is the most basic mechaism by which ulcers are healed?

decrease acid

5

What are common signs of ulcers in dogs?

Vomiting +/- blood
Weight loss + Anaemia
Black tarry stool

6

What are common signs of ulcers in cats?

Vomiting +/- blood
Anemia + Weight loss + loss of appetite
Abdominal pain
Tarry stool

7

What is EGUS?

Equine gastric ulcer syndrome

8

What type of horse is most prone to ulcerations?

Racing horses (~60%)

9

What is the most basic mechanism by which horses get ulcers?

Always producing acid, so must be able to eat at all times to prevent erosion of stomach lining

10

What are signs that a horse may have a stomach ulceration?

Poor appetite + Lethargy + Weight loss + Poor performance + Attitude

11

What are the two parts of a horses stomach?

Non-glandular + Glandular

12

What is ESGUS?

Non-glandular

13

What is EGGUS?

Glandular

14

What portion of the stomach is most prone to ulcerations?

Non-glandular

15

What is an important mechanism by which H+ is taken into the parietal cell?

Histamine from ECL cell stimulates H2

16

What is the important protective portion of the molecular cascade of parietal cells?

PGE2 + PGI2 --> stimulates EP3

17

What does EP3 do? (two different cells)

Superficial epi cell = mucous + bicarb
Parietal cell = prevents H+ secretion

18

What inhibits PG's?

NSAIDs

19

What do antacids block?

H+ directly

20

What do proton pump inhibitors inhibit?

H/K ATPase

21

What is the pH at the mucous layer?

7

22

What is the pH in the gastric lumen?

2

23

What does Mg do in the stomach?

Binds H+
Not absorbed
Also acts as a laxative

24

What does Al do in the stomach?

Binds H+
Not absorbed
Causes constipation
Combine with Mg

25

What two transmitters increase acid production?

M1/M3 = ACh
H2 = Histamine

26

What are the three elements used in antacids?

Aluminum + Magnesium + Calcium

27

What is the product of antacids with H+?

Water + Neutral salt

28

When should antacids not be used? Why?

Renal failure
Mg will accumulate = CNS toxicity

29

What side effect do you see with Calcium as an antacid?

Creates CO2 = Burping

30

When should antacids be used, what types of Gi disorders?

Acidity in mild gastric disease
Don't work with ulcerations

31

When is Mg used to cause diarrhea in cattle, goats, and sheep?

Grain overload

32

What type of receptor are H2's linked with?

Gs = inc. cAMP

33

What are the four H2 antagonists?

Cimetidine
Ranitidine
Famotidine
Nizatidine

34

What is the result of H2 antagonists?

Reduction in Gastric acid + Pepsin secretion

35

How should H2 antagonists be handled in renal patients?

50% the dose

36

What should you watch out for with cimetidine?

Many drug interactions due to CYPs inhibition

37

What can occur with ranitidine?

Increase motility through M stimulation + decrease in acid

38

When is ranitidine recommended?

Feline megacolon

39

When are H2 blockers benefical?

Gastric + Duodenal ulcerations
Gastric erosions
Esophageal reflux disease
Gastritis

40

What H2 blocker is used in horses for ESGUS?

Ranitidine

41

Why are H2 blockers used in severe allergic reactions?

Decrease vasodilation effect of histamine on BV

42

How do proton pump inhibitors work?

Irreversible blockade of acid formation

43

How long does it take proton pump inhibitors to work?

2 to 5 days

44

Why do proton pump inhibitors have to be taken continuously?

Body will continue replacing H/K ATPase pumps

45

How should proton pump inhibitors be given?

Empty stomach for best absorption
Eat 30 min later

46

Where are proton pump inhibitors absorbed in the GI tract?

Intestine

47

What are the three proton pump inhibitors?

Omeprazole
Esomeprazole
Pantoprazole

48

When is a good time to use proton pump inhibitors in dogs?

Long-lasting acid suppression needed
Reduces risks of ulcers in dogs taking NSAIDs

49

What can proton pump inhibitors treat in horses?

EGGUS + ESGUS

50

What needs to be given with PPI in EGGUS?

Cytoprotectives

51

What is important to tell the client when giving them PPI's?

DO NOT CRUSH UP, need to be protected from stomach acid

52

What are the most effective drugs in healing ulcers?

PPI's

53

What are possible adverse reactions to PPI's?

Bacterial overgrowth
Aspiration pneumonia
Long-term increase in gastrin
Gastric cancer

54

What does omeprazole inhibit? Do you need to worry about this?

P450's. No, doesnt inhibit enough of it

55

How do cytoprotective agents work?

Create physical barrier between gastric epi + gastric lumen

56

How does bismuth work?

Bind to ulcer bed = protective coating
Increases PG's = increased Bicard + decrease pepsin

57

What is important to remember about bismuth?

Toxic to cats and probably dogs due to salicylate

58

What are the side effects of sucralfate?

Constipation + Stomach upset

59

Why does sucralfate cause constipation?

Aluminum

60

When is sucralfate used in horses?

EGGUS

61

What is used with sucralfate in EGGUS?

omeprazole

62

What is misoprostol?

Synthetic PG's E1 analogue

63

When is misoprostol used?

NSAID use in older dogs

64

What side effects can occur with misoprostol?

Diarrhea + Abdominal cramps
Increase nephrotoxicity of other drugs

65

What does erythromycin stimulate?

Motilin

66

What does cisapride stimulate?

Serotonin

67

What are the two prokinetic D2 antagonists?

Metoclopramide + Doperiodone

68

What do the prokinetic, D2 antagonists do?

Increase ACh release via D2 blockage
Reduce gastroesophageal reflux via increase sphincter tone

69

What prokinetic drug is used in cats and dogs?

Metoclopramide

70

What side effect can occur with metoclopramide? Why?

Can get into CNS
Excitement in horses + Anxiety + Involuntary movements
Increase potlactin

71

When is metoclopramide used in dogs?

Vomiting disorders
Delayed gastric emptying (post-operative)
Decrease gastroesophageal reflux

72

What is important to know about metoclopramide?

NOT APPROVED IN FOOD ANIMALS

73

What is domperidone used for?

Increase prolactin secretion
Treat fescue toxicity + agalactia in mares
Vomiting + Reflux

74

When is bethanechol used in dogs? Why?

Dogs have striated muscle in esophagus
Increases contraction
Treatment of megasesophagus
Cattle = cecal dilatation

75

When is erythromycin used?

Diabetic gastroparesis in dogs

76

What does Serotonin increase cause?

Increase ACh = increase motility SM

77

When is ipecac used?

After ingestion of toxins or drug overdose

78

How does apomorphine work?

Stimulates D2 in CTZ

79

When should you NEVER induce vomiting?

If animal has swallowed strong acid or alkali compound

80

What is really good at making cats vomit?

Xylazine

81

What is a neurokinin antagonist in vet medicine?

Maropitant

82

What does a neurokinin antagonist do?

Inhibit Substance P on NK1 receptor

83

What are neurokinin antagonoist used for?

Acute vomiting
Motion sickneess
Chemotherapy