Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Physiology 1 : GI > Pharmacological basis of GI treatment > Flashcards

Pharmacological basis of GI treatment Flashcards

1
Q

What are 4 examples of H2 receptor antagonists?

A

→ranitidine
→cimetidine,
→ famotidine
→nizartidine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are clinical uses of H2 receptor antagonists?

A

→ Peptic ulcer reflex oesophagitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What do H2 receptor antagonists inhibit and promote ?

A

→Inhibits histamine, ACh and gastrin stimulated acid secretion on parietal cells
→Promotes healing of duodenal ulcers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does stopping treatment of H2 receptor antagonists do?

A

→Stopping treatment means relapse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How is the H+/K+ pump activated by action of gastrin?

A

→Gastrin can activate ECL cells to release histamine

→ it binds to H2 receptors on parietal cells

→activates the H+/K+ ATPase pump

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What do H2 receptor antagonists reduce?

A

→Reduces gastric acid secretion and as a consequence reduces pepsin secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What can H2 receptor antagonists decrease?

A

→Can decrease basal and food stimulated acid secretion by 90%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What can 4 side effects of H2 receptor antagonists be?

A

→diarrhoea
→muscle cramps
→transient rashes
→hypergastrinaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a side effect of cimetidine?

A

→ Gynecomastia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does cimetidine inhibit?

A

→ P450 enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does a low IC50 mean?

A

→ Drug is more powerful

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does IC50 mean?

A

→ Inhibitory concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are 4 examples of proton pump inhibitors?

A

→ omeprazole
→ lanzoprazole
→ pantoprazole
→ rabeprazole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are clinical uses of proton pump inhibitors?

A 
→Peptic ulcer
→ reflux oesophagitis
→therapy for H. Pylori
→ treatment for Zollinger-Ellison 
→Drugs of choice if hyper-secretion occurs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the mechanism of action of proton pump inhibitors?

A

→ Weak bases - inactive at neutral pH and irreversibly inhibit the H+/K+ ATPase pump
→ Decrease basal and food stimulated gastric acid secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are side effects of proton pump inhibitors?

A 
→Headache
→diarrhoea
→ mental confusion
→rashes
→somnolence
→ impotence
→ gynecomastia
→ dizziness
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What protects the gastric mucosa?

A

→ PGE1

→ PGE2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What drugs protect the gastric mucosa?

A

→ misoprostol - stable analogue of PGE1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What does misoprostol inhibit?

A

→Inhibits basal and food stimulates gastric acid secretion
→Inhibits histamine and caffeine induced gastric secretion
→Inhibits the activity of parietal cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does misoprostol increase and induce?

A

→Increases mucosal blood flow and can augment the secretion of HCO3- and mucus
→Induces labour/abortion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does metoclopramide do?

A

→inhibits pre and postsynaptic dopamine (inhibits ACh) receptors as well as 5HT3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What do 5HT3 receptors do?

A

→receptors which inhibits vomiting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does dopamine inhibit?

A

→ ACh release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How does dopamine inhibit ACh?

A

→inhibits the release of ACh from intrinsic myenteric cholinergic neurons by activating prejunctional D2 receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What kind of effects does dopamine have on the gut and where?
→relaxant effects on the gut by activating D2 receptors in the lower oesophageal sphincter and stomach
26
What does dopamine do in the distal and proximal areas of the gut?
→can induce contraction in the proximal | →relaxation in the distal
27
What does increased ACh mean?
→Increased ACh means increased intragastric pressure →due to increased LOS tone → increased tone of gastric contractions
28
What does an increase of ACh do to contraction and emptying?
→These improve antral duodenal contraction which →accelerates gastric emptying →relaxes the pyloric sphincter
29
What two properties does metoclopramide have?
→ antiemetic properties via central effects | →relieves headache via central effects
30
What is metoclopramide useful for?
→GI reflux
31
What does metoclopramide stimulate and accelerate?
→ S: gastric motility | → A: gastric emptying
32
What neurons does metoclopramide stimulate?
→inhibitory nitregic neurons | →mediate NO release
33
What are the 6 effects of metoclopramide?
→Inhibits presynaptic and postsynaptic D2 receptors →Stimulates the release of ACh / SP from enteric neurons →Elicits mixed 5-HT agonist and antagonist effects, e.g., stimulates excitatory 5-HT4 receptors (ENS), but inhibits 5-HT3 receptors (CNS); →Stimulates inhibitory nitregic neurons – mediate NO release →Increases intragastric pressure -↑ LOS and gastric tones →Motility stimulant - improves antro-duodenal coordination and accelerated gastric emptying
34
What are 3 examples of antispasmodic agents?
→Propantheline → dicloxerine → mebeverine
35
What do antispasmodic agents do?
→Decrease spasm in bowel, they have relaxant action on GIT (smooth muscle in GIT)
36
What is propantheline?
→antimuscarinic agent
37
What do muscarinic receptor antagonists do?
→inhibit parasympathetic activity which reduces spasm in the bowel
38
What is the goal in pharmacological intervention in gastric ulcer?
→Reduce acid secretion with H2 receptor antagonists →Neutralise secreted acid with antacids →Attempt to eradicate H. pylori
39
What kind of bacteria is H.Pylori?
→H.Pylori is a gram negative bacillus
40
What is the mechanism of action of antacids?
→Neutralize gastric acid | →increase the pH of gastric acid
41
What does bismuth chelate do?
``` →Protects gastric mucosa →Forms a base over crater of ulcer →Adsorbs pepsin →Increased HCO3- and PG secretion →Toxic against H. Pylori - used as part of a triple therapy to eradicate it →Blackens stool and tongue ```
42
What can bismuth chelate cause?
→Can cause encephalopathy
43
How do prostaglandins protect the mucosal layer?
→Stimulating bicarbonate secretion →Reducing H+ secretion →Promotes vasodilation
44
Why do NSAIDS (e.g. aspirin) cause gastric bleeding?
→ Inhibit PG synthesis
45
What reduces bleeding from NSAIDs?
→Celecoxib | → rofecoxib
46
What is H.Pylori a risk factor for?
→ gastric cancer
47
What is a 3 combination therapy for H.Pylori?
Omeprazole, amoxicillin and metronidazole
48
What cytoprotective effects does bismuth chelate have?
→Provide a physical barrier (coat) over the surface/base of the ulcer →Enhances local synthesis of PGs →Promote bicarbonate secretion
49
What reaction happens if metronidazole is taken with alcohol?
→Disulfiram like reaction
50
What does disulfiram do to alcohol?
→ Inhibits acetaldehyde dehydrogenase so acetaldehyde builds up
51
What are consequences of constipation?
``` →Headache →Loss of appetite →Nausea →Abdominal distension and stomach pain →Holding of fecal matter → Water loss and drier feces → painful and harder to defecate ```
52
What are 3 causes of constipation?
→Decreased motility of large intestine →Old age →Damage to enteric nervous system of colon
53
What are factors that can increase colonic motility?
→Increased fibre, cellulose and complex polysaccharides →Bran, fruits, vegetables with high fibre →Laxatives but excessive use - decrease in responsiveness →Mineral oil - lubricates feces →Castor oil - stimulates motility of colon
54
What are alarm signs for people with chronic constipation?
``` →Acute onset in older individuals →Weight loss →Blood →Anaemia →Family history of colon cancer or inflammatory bowel disease ```
55
What can purgatives do?
→modulate/hasten food transit in the intestine
56
What are bulk laxatives?
→Bulk laxatives - methylcellulose | →Plant gums (sterculia, agar, linseed, bran)
57
What do bulk laxatives do?
→They retain water in the gut lumen → promote peristalsis but take a few days to work →Increase the stools solid content /Bloating and flatulence
58
What do osmotic laxatives do?
→Increases and maintains the volume of fluid in the lumen of the bowel by osmosis
59
What do high doses of osmotic laxatives cause?
``` →flatulence → cramps →diarrhoea → vomiting →tolerance ```
60
What do anti-diarrheal agents do?
→Maintain body fluids and electrolytes
61
What are 4 causes of diarrhoea?
→Infectious agents →Toxins →Anxiety →Drugs
62
What does oral rehydration therapy do?
→maintain fluid and electrolyte balance
63
What does loperamide do?
→Selective on GIT →Decreases passage of feces →Decreases duration of illness
64
What does bismuth subsalicylate do?
→Decreases fluid secretion in bowel →Safe for young children →Tinnitus and blackening of stool
65
What type of drug is loperamide?
→Opioid receptor agonist
66
Where does loperamide exert its effects?
→Exerts effects on mu opioid receptor of the myenteric plexus of the large intestine
67
What does loperamide do to the GIT?
→reduces smooth muscle activity in the GIT | →reduces passage of feces
68
What does loperamide increase?
→Increases haustral mixing of proximal colon
69
What does loperamide inhibit?
→Inhibits propulsive mass movement of the distal colon
70
Why does loperamide not have CNS effects?
→ Does not cross the blood brain barrier
71
What does loperamide reduce?
→ Force and speed of colonic movements

Physiology 1 : GI (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions