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Pharmacology- Katzung (Spring 2019) > Gastrointestinal Drugs > Flashcards

Flashcards in Gastrointestinal Drugs Deck (66)
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1
Q

Mention 6 major PPIs.

A
  1. Omeprazole
  2. Esomeprazole
  3. Dexlansoprazole
  4. Lansoprazole
  5. Pantoprazole
  6. Rabeprazole
2
Q

What is the mechanism of action of omeprazole?

A

Irreversible blockade of H+/K+ ATPase in active gastric parietal cells.

3
Q

What is the clinical use of omeprazole?

A
  1. Peptic ulcer disease
  2. GERD
  3. Erosive gastritis
4
Q

What are the pharmacokinetics of omeprazole?

A

Half-lives much shorter than duration of action.

5
Q

What are the side effects of omeprazole?

A
  1. Low toxicity

2. Reduction of stomach acid may reduce absorption of some drugs and increase that of others.

6
Q

Mention 4 major H2 blockers.

A
  1. Cimetidine
  2. Famotidine
  3. Nizatidine
  4. Ranitidine
7
Q

Are H2 blockers safe drugs?

A

Yes - Available OTC.

8
Q

What is important to keep in mind about cimetidine?

A

In contrast to other H2 blockers, it is a weak antiandrogenic agent and a potent CYP inhibitor.

9
Q

What is the sucralfate?

A

Polymerizes at the site of tissue damage and protects against further damage.
Very insoluble - no systemic effects.

10
Q

How many times must sucralfate be given?

A

4x daily.

11
Q

What are the 4 categories of prokinetic GI agents?

A
  1. Metoclopramide
  2. Domperidone
  3. Cholinomimetics (neostigmine)
  4. Macrolides (erythromycin)
12
Q

What is the mechanism of metoclopramide?

A

D2 blocker - increases gastric emptying and intestinal motility.

13
Q

What is the clinical use of metoclopramide?

A
  1. Gastric paresis (in diabetes)

2. Antiemetic

14
Q

What are the pharmacokinetics of metoclopramide?

A

Oral and parenteral formulations.

15
Q

What are the side effects of metoclopramide?

A

Parkinsonian symptoms due to block of CNS D2 receptors.

16
Q

Mention a drug similar to metoclopramide, but less CNS toxic.

A

Domperidone

17
Q

Where are macrolides (erythromycin) used as a prokinetic agent?

A

In diabetic gastroparesis but tolerance develops.

18
Q

What is the mechanism of action of magnesium hydroxide, other non absorbable salts and sugars?

A

Osmotic agents that increase water content of stool.

19
Q

What is the clinical use of magnesium hydroxide?

A

Simple constipations - bowel prep for endoscopy (especially PEG (pegylated) solutions).

20
Q

How is magnesium hydroxide administered?

A

Orally

21
Q

What are the side effects of magnesium hydroxide?

A

Renal impairment.

22
Q

Mention 2 bulk-forming agents.

A
  1. Methylcellulose

2. Psyllium

23
Q

What do these bulk-forming agents do?

A
  1. Increase volume

2. Stimulation evacuation

24
Q

Mention two stool surfactants.

A
  1. Docusate

2. Mineral oil

25
Q

What do those two stool surfactants do?

A
  1. Lubricate stool

2. Ease passage

26
Q

Mention 2 stimulating stool agents.

A

Senna and cascara.

27
Q

What may these stimulating stool agents cause?

A

Cramping.

28
Q

Mention 2 chloride channel activators.

A
  1. Lubiprostone

2. Prostanoic acid derivative

29
Q

What is the mechanism of action of chloride channel activators?

A

Stimulate chloride secretion into intestine, increasing fluid content.

30
Q

Mention 2 opioid receptor blockers that are used as laxatives.

A
  1. Alvimopan

2. Methylnaltrexone

31
Q

What is the mechanism of action of opioid laxatives?

A

Block intestinal μ receptors but do not enter CNS, so analgesia is maintained.

32
Q

What is the mechanism of action of the antidiarrheal loperamide?

A

Activates μ opioid receptors in enteric nervous system and slows motility with negligible CNS effects.

33
Q

What is the clinical use of loperamide?

A

Nonspecific, non infectious diarrhea.

34
Q

How is loperamide administered?

A

Orally

35
Q

What are the side effects of loperamide?

A

Mild cramping but little or no CNS effect.

36
Q

Mention a drug similar to loperamide.

A

Diphenoxylate - at higher doses can cause CNS opioid effects and toxicity.

37
Q

What is the mechanism of action of alosetron?

A

5-HT3 blocker of high potency and duration of binding.

–> Reduces smooth muscle activity in GI tract.

38
Q

What is the clinical use of alosetron?

A
  1. Severe diarrhea

2. Predominant IBS in women

39
Q

How is alosetron administered?

A

Orally

40
Q

What are the side effects of alosetron?

A
  1. Rare but serious constipation
  2. Ischemic colitis
  3. Bowel infarction
41
Q

Besides alosetron, what other drugs are used for IBS?

A
  1. Anticholinergics

2. Chloride channel activator –> Lubiprostone is useful in constipation predominant IBS in women.

42
Q

Mention the 6 general categories of drugs that are used as antiemetics.

A
  1. 5-HT3 blockers
  2. Corticosteroids
  3. Antimuscarinics
  4. Phenothiazines
  5. Cannabinoids
  6. Aprepitant
43
Q

Mention 4 major 5-HT3 blockers.

A
  1. Ondasetron
  2. Dolasetron
  3. Granisetron
  4. Palonosetron
44
Q

What is the clinical use of ondasetron?

A

Prevention of chemotherapy-induced and post-op nausea and vomiting.

45
Q

What are the pharmacokinetics of ondasetron?

A

Oral and parenteral formulations.

46
Q

What is a possible side effect of ondasetron?

A

May slow colonic transit.

47
Q

What is the mechanism of action of corticosteroids as antiemetics?

A

Not known, but useful in antiemetic IV cocktails.

48
Q

What antimuscarinic agent do we use as antiemetic?

A

Scopolamine - effective in emesis due to motion sickness.

49
Q

What cannabinoid is used as antiemetic?

A

Dronabinol - for use in chemo-induced nausea and vomiting, but is associated with marijuana effects.

50
Q

What is the mechanism of aprepitant as an antiemetic?

A

Neurokinin 1 blocker - for use in chemo-induced nausea and vomiting - associated with fatigue, dizziness, diarrhea, and CYP interactions.

51
Q

What drugs are used for inflammatory bowel disease?

A
  1. Mesalamine
  2. Azo compounds
  3. Glucocorticoids
  4. Immunosuppressant antimetabolites
  5. Anti-TNF drugs
  6. Natalizumab
52
Q

What is the mechanism of action of mesalamine (5-aminosalicylate)?

A

Uncertain - may be inhibition of eicosanoid inflammatory mediators.

53
Q

What is the clinical use of mesalamine?

A

Mild to moderately severe Crohn’s disease and ulcerative colitis.

54
Q

What are the pharmacokinetics of mesalamine?

A

Various formulations designed to deliver drug to distal ileum and colon.

55
Q

What are the side effects of mesalamine?

A

Little or no toxicity.

56
Q

What are the main azo compounds use in IBD?

A
  1. Dalsalazide
  2. Olsalazine
  3. Sulfasalazine
57
Q

What is the natalizumab?

A

Antibody that blocks leukocyte integrins - may cause multifocal leukoencephalopathy.

58
Q

What is the mechanism of action of pancrelipase?

A

Replacement enzymes from animal pancreatic extracts that improve digestion of fat, protein, and carbohydrate.

59
Q

What is the clinical use of pancrelipase?

A

Pancreatic insufficiency due to cystic fibrosis, pancreatitis, and pancreatomy.

60
Q

What are the pharmacokinetics of pancrelipase?

A

Taken with every meal.

61
Q

What is a possible side effect of pancrelipase?

A

May increase incidence of gout.

62
Q

What is the mechanism of action of ursodiol?

A

Reduces cholesterol secretion into bile.

63
Q

What are the clinical uses of ursodiol?

A

Gallstones in patients refusing or not eligible for surgery.

64
Q

How is ursodiol administered?

A

Orally

65
Q

What are the side effects of ursodiol?

A

Little or no toxicity.

66
Q

What are the 3 main drug categories that are used in acid-peptic diseases?

A
  1. Proton pump inhibitors (PPIs)
  2. H2 blockers
  3. Antacids

Decks in Pharmacology- Katzung (Spring 2019) Class (52):