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Flashcards in GI Drugs - Kumar TS Deck (132):
0

What neurotransmitter stimulates appetite? Which one inhibits appetite?

Stimulated by GABA
inhibited by serotonin

1

Which appetite stimulant is used in cats and acts through GABA?

diazepam (valium)

2

Which appetite stimulant for cats is an antihistaminic and antiserotonin agent?

cyproheptadine

3

What is the anti obesity drug used for dogs?

dirlotapide

4

What animals are NOT able to vomit effectively?

horses, ruminants, rodents

5

What are the the 4 afferent sources that can stimulate vomiting?

CTZ
vestibular
peripheral sensory receptors
higher CNS

6

What are the 5 neurotransmitters involved in vomiting?

dopamine, histamine, serotonin, Ach, substance P

7

What is the most important neurotransmitter for the CTZ to initiate vomiting?

dopamine

8

What is the neurotransmitters used to cause vomiting in the vestibular system?

Histamine and muscarinic

9

What is the primary neurotransmitter for peripheral sensory receptors?

acetylcholinne

10

What are the transmtters used for higher CNS centres for vomiting?

cholinergic and histamine

11

What pathway initiates emesis from increased intracranial pressure?

limbic pathway

12

What is the primary neurotransmitter used in psychogenic vomiting?

acetylcholine

13

Where are NK-1 receptors found?

emetic center and CTZ

14

Which peripheral acting emetic should not be dosed twice in cats?

ipecac

15

What are the 3 peripheral acting/reflex emetics?

salt water, hydrogen peroxide, ipecac

16

What are the 2 centrally acting emetics?

apomorphine
xylazine

17

Which centrally acting emetic is used in cats?

xylazine

18

What is the MOA for apomorphine?

opiod - dopaminergic receptors in CTZ`

19

How is apomorphine adminisstered?

subq or conjuctival

20

What is the contraindication of apomorphine?

animals with existing central depression because it depresses respiratory centers

21

What is the MOA of xylazine?

stimulates alpha 2 receptors in CTZ

22

What are the side effects of xylazine?

bradycardia

23

What can be used to prevent emesis at the vestibular apparatus?

anti histamines

24

What antimuscarinic can cross the BBB in dogs to prevent emesis?

scopolamine

25

What are the SE of antimuscarinics?

xerostomia, drowsiness, constipation, urine retention

26

What are the 5 anti emetic drugs acting on the CTZ?

1. phenothiazines
2. butyrophenone derivatives
3. metoclopramide
4. peripheral serotonin antagonists
5. Nk1 receptor blockers - cerenia

27

What antiemetic drugs are "broad" spectrum?

phenothiazines

28

What should be done before giving animals phenothiazines (ace)?

fluid replacement

29

What are the contraindications of phenothiazines?

animals with seizures

31

What anti emetic effectively antagonizes apomorphine induced emesis?

metoclopramide

32

What is the MOA for metoclopramide?

dopamine antagonist, serotonin agonist and serotonin receptor antagoonist to CTZ

33

What CTZ anti emetic blocks transmission to CTZ an interferes with action of serotonin on peripheral receptors in GI tract?

peripheral serotonin antagonists (cyproheptadine)

34

What drug acts by blocking NK-1 receptor?

maropitant citrate (cerenia)

35

Why can't cerenia be used in puppies less than 11 weeks of age?

can induce bone marrow hypocellularity

36

What are the 3 ways anticholinergic drugs exert its antiemetic activity?

inhibit vagus
relax GI smooth muscle
inhibit GI secretions

37

What receptors do butyrophenone derivatives act on?

antidopaminergic

38

What are the 2 SE of butyrophenone derivatives?

sedation and hypotension

39

What drug effectively antagonizes apomorphine induced emesis?

metoclopramide (reglan)

40

Why is the bioavailability of metclopramide only 50%?

extensive hepatic first pass metabolism

41

What are the SE of metclopramide in horses and cats?

hyperactivity, restlessness, tremors

42

What group of drugs are indicated for emesis induced by chemotherapeutic agents?

peripheral serotonin antagonists

43

What peripheral serotonin antagonist is used in small animals?

cyproheptadine (periactin)

44

What are some other examples of peripheral serotonin antagonists?

granisetron, palonosetron, ondansetron

45

What anti emetic is a NK-1 receptor blocker?

maropitant citrate (cerenia)

46

What is the contraindication of maropitant citrate (cerenia)?

puppies less than 11 weeks - bone marrow hypocellularity

47

What are the 3 ways anticholinergics exert antimetic activity?

inhibit vagus
relax GI spasm
inhibit GI secretions

48

What is the one drawback of anticholinergic drugs?

delays gastric emptying - dont use for more than 3 days

49

What are the 3 MOA for drugs to modulate gastric acid secretion?

block endogenous secretagogues
block proton pump
enhance cytoprotective effect

50

Which antisecretory drug is anticholinergic and selective for gastric M1 receptors?

pirenzepine

51

Which H2 receptor antagonist (of the antisecretory drugs) has the longest duration of action?

famotidine

52

What is the order of potency for H2 receptor antagonists of the antisecretory drugs?

famotidine>ranitidine>nizatidine>cimetidine

53

What drug is clinically useful in preventing acetaminophen toxicity in case of accidental overdose?

cimetidine

54

What are the SE of H2 receptor antagonists?

thrombocytopenia, rebound acid hypersecretion, relapse ulcers, cutaneous drug eruption in cats

55

What is the MOA of omeprazole (prilosec)?

inhibits proton pump

56

What are the clinical indications of omeprazole (prilosec)?

short term treatment of gastric ulcers associated with gastrinomas

57

What are the 4 adverse reactions to omeprazole (prilosec)?

1. suppression of acid barrier - bacteria
2. aspiration pneuomonia (megaesophagus)
3. hypergastrinemia
4. inhibits CYp450

58

What drug does not alter serum gastrin levels, hence prevents rebound acid hypersecretion?

misoprostol (cytotec)

59

What are the 3 non-systemic antacids?

salts of aluminum, magnesium, calcium

60

What is the antacid of choice for mild ruminal acidosis?

aluminum hydroxide

61

What drug is used as a systemic antacid?

sodium bicarbonate

62

What are the 4 SE of antacids and which drug is most associated with each SE?

constipation - Al and Ca
Diarrhea - Mg
Hypercalcemia - Ca
hypophosphatemia - Al

63

What drug is considered a potent agent in gastroduodenal ulcer healing caused by NSAIDs?

misoprostol

64

What drug binds to the gastric ulcer, protects it, and promotes healing?

sucralfate

65

What cytoprotective drug should be used cautiously in cats?

bismuth subsalicylate (glucoronidation)

66

What is the MOA of bethanechol?

cholinergic agonist, enhances amplitude of GI contractions

67

What are the indications of bethanechol?

postoperative ileus, urinary retention

68

What are the SE of bethanechol?

obstruction, peritonitis, intestinal wall is compromised

69

What is the MOA of metoclopramide?

enhances release of Ach in GI. peripherally antagonizes D2 receptors (blocks inhibitory)

70

What are the 4 actions of metoclopramide?

increase tone of esophageal sphincter
increase GI contractions
relax pyloric sphicter, rapid emptying
penetrates BBB - antagonizes D receptors

71

What are the 2 clinical indications of metoclopramide?

reflux esophagitis
gastric motility disorders

72

What drug has the broadest spectrum of all the prokinetic agents?

cisapride

73

What are the indications for cisapride?

same as metoclopramide, constipation (mega colon in cats), and post operative ileus

74

What is a prokinetic agent that peripherally antagonizes dopamine receptors only?

domperidone

75

What are the main indications for using anticholinergic drugs for GI?

control diarrhea in calves and mild colin

76

What is the net effect of using opiods on the GI?

decreased GI motility and secretions
increase tone of sphincters

77

Opiods are superior to antimuscarinics in treating what?

non specific diarrhea

78

What are the contraindications for using opiods during diarrhea?

when diarrhea is from invasive bacterial infection

79

What is diphenoxylate used for clinically?

anti-diarrheal

80

What is the active metabolite of diphenoxylate?

difenoxin

81

What does loperamide do?

reduce excessive intestinal secretion, prolongs transit time

82

What drug is a tincture of opium and used as an antidiarrheal in foals?

paregoric

83

What Gi protectant and adorbent should be used cautiously in cats?

bismuth subsalicylate

84

What 2 drugs absorb E-coli enterotoxins?

Bismuth salts and activated charcoal

85

What is the best choice for emergency treatment of poisoning?

activated charcoal

86

What should be done after administering activated charcoal?

saline laxative 30-45 minutes afterwards

87

What does cholestyramine bind to?

acidic side chains of bile acids

88

What is the clinical indication for cholestyramine

pruritis associated with increased bile acids

89

What are the adverse effects of cholestyramine?

nausea, constipation, steatorrhea, decreased B vitamins

90

What kind of stool do cathartics/purgatives produce?

more fluid than laxatives

91

What are the 3 emollient laxatives?

mineral oil, docusate sodium, paraffin

92

What are aspects of emollient laxatives?

unchanged, not absorbed, soften and lubricate fecal mass

93

What are aspects of bulk forming laxatives?

hydrophilic in nature, reflex peristaltic contractionn

94

What are the 2 bulk forming laxatives?

bran, psyllium granules

95

What is the most useful mild laxative for horses with sand colic?

psyllium granules

96

What animals are saline/osmotic purgatives contraindicated in?

dehydrated animals

97

Which osmotic purgative is fermented to organic acids and lowers the pH of colon contents?

lactulose

98

What can lactulose be used to treat?

dogs and cats - constipation, hepatic encephalopathy
horses - hepatic encephalopathy
can be admin by rectum

99

What are examples of irritant/stimulant cathartics?

castor oil, ricinoleate, anthraquinones

100

What is the MOA of irritant cathartics?

stimulate local myenteric reflexes, provoke fluid accumulation in intestinal lumen by active secretory mechanisms

101

What irritant stimulant can cause superpurgation in horses when administered repeatedly?

anthraquinone

102

What is the MOA of neuromusular purgatives?

muscarinic actions - increase motility

103

What is the contraindication of neuromuscular purgatives?

mechanical obstruction of intestine

104

What is the contraindication of ALL cathartics??

animal showing signs of abdominal pain

105

what are the adverse effects of overdosing cathartics?

diarrhea, abdominal colic, dehydration, shock

106

What type of enema preparations should not be used in cats?

ones that contain phosphate

107

What can be given to foals to help pass the meconium?

docusate sodium

108

What do cholagogues do?

contraction of gall bladder

109

What do choleretics do?

increase secretion of bile

110

What can be used to dissolve gallstones non surgicially?

Ursodeoxycholic acid (UDCA)

111

What drug can reduce the surface tension of gas bubbles causing them to coalesce?

dimethicone

112

What drug is used in the prevention and treatment of frothy bloat?

poloxalene

113

What is contra indicated in ruminal bloat and stabalizes foam?

fish oils

114

What do phenothiazines NOT control for emesis?

labyrinthine stimulation (vestibular?)

115

What are the 3 centrally acting emetics that are antidopaminergics?

phenothiazines
butyrophenones
metoclopramide

116

What are examples of phenothiazine drugs?

chlorpromazine
prochorperazine
triflupromazine
promethazine
trifluperazine

117

What are examples of peripherally acting antiemetics?

demulscents, antacids, protectants such as kaolin, pectin
anticholinergic drugs, prokinetics

118

What can chronic administration of antisecretory drugs to GI result in?

achlorhydria (malabsorption)

119

What are the 2 SE associated with using misoprostol for decreasing gastric secretion?

diarrhea
increases uterine contraction (pregnancy contraindicated)

120

How does omeprazole inhibit the proton pump?

goes to acidic environment of parietal cells, protonated and irreversibly binds pump

121

What 2 non systemic antacids can be combine to balance bowel movements?

aluminum and magnesium

122

What does sucralfate require in order to break up and bind to ulcers?

acidic environment

123

What part of Bismuth subsaliicylate is absorbed?

salicylate

124

What is postoperative illeus?

atony or paralysis of stomach or bowel

125

What is the most potent and broad spectrum prokinetic agent?

cisapride

126

What prokinetic acts PERIPHERALLY as a dopamine antagonist?

domperidone

127

Mineral oil should not be used with what because emulsification of the oil would facilitate its absorption?

docusate sodium

128

What species should diphenoxylate be used cautiously because it causes excitabilty?

cats

129

What happens to castor oil after it is ingested?

hydrolyzed by pancreatic lipase into glycerol and ricinoleic acid

130

What does ricinoleate do?

reduces absorption of fluid and stimulates peristalsis

131

What are 2 substances that are cholagogues?

dietary fat and concentrated magnesium sulfate

132

What can be administered for a retention enema thru a catheter?

acetylcysteine - breaks bonds