Pharmacology of Prokinetics, Acid-Peptic Disorders, and Antiemetics (Quiz)

Question 1

what is gastroparesis

Answer 1

• failure of the stomach to empty properly

Question 2

what does motilin do

Answer 2

• stimulate motility

Question 3

what does dopamine do for motility

how

Answer 3

• inhibits motility

- inhibitory presynaptic dopamine receptor (D2)

Question 4

what does acetylcholine do for motility

Answer 4

• stimulates motility

Question 5

MOA of Metoclopramide

Answer 5

• inhibition of dopamine D2 receptor

- increase contraction and motility

Question 6

Toxicities of Metoclopramide

short or long term use

Answer 6

• acute dystonia - short term
• tardive dyskinesia - long term
• hyperprolactinemia
• anxiety, restlessness, depression

Question 7

what are acute dystonia and tardive dyskinesia known as

Answer 7

• extrapyramidal symptoms (EPS)

Question 8

how EPS’s caused

important brain parts involved

Answer 8

• inhibition of central dopamine pathway that regulates skeletal muscle movement
• substantia nigra
• dorsal striatum

Question 9

how does Metoclopramide cause hyperprolactinemia

Answer 9

• inhibits central dopamine pathway that inhibits release of prolactin
• therefore excessive prolactin secreted

Question 10

Erythromycin MOA

Answer 10

• motilin receptor agonists

Question 11

side effect of Erythromycin

Answer 11

• GI distress

Question 12

pharmacokinetics issues with Erythromycin

Answer 12

• tachyphylaxis (desensitization) after 10-14 days

Question 13

what drug do you use if metoclopramide fails

Answer 13

• erythromycin

Question 14

MOA of Neostigmine

Answer 14

• indirect acting cholinergic agonist

- inhibits acetylcholinesterase and increases amount of acetylcholine at synapse

Question 15

toxicities of Neostigmine

Answer 15

• pro parasympathetic effects
• excessive saliva production
• decreased CO
• bradycardia

Question 16

what is the antidote to Neostigmine

Answer 16

• atropine

Question 17

role of prostaglandin E2

Answer 17

• inhibits gastric acid secretion

Question 18

MOA of Sucralfate

Answer 18

• polymerizes at low pH of stomach
• negatively charged so binds positively charged proteins in stomach ulcer
• forms a barrier

Question 19

types of antacids

Answer 19

• NaHCO3
• CaCO3
• Al(OH)3
• Mg(OH)2

Question 20

MOA of antacids

Answer 20

• directly neutralize stomach acid

Question 21

toxicity of NaHCO3

Answer 21

• metabolic alkalosis

Question 22

toxicity of Mg(OH)2 and Al(OH)3

how do we solve this

Answer 22

• diarrhea
• constipation
• combine the two to off-set each other’s toxicities

Question 23

toxicity of antacids

how

Answer 23

• hypophosphatemia

- molecules are insoluble and prevents PO4 absorption

Question 24

which are the antihistamines

Answer 24

• Ranitidine
• Famotidine
• Cimetidine

Question 25

MOA of Antihistamines

Answer 25

- competitive, reversible inhibitors of H2 receptor in parietal cells

Question 26

can acid-peptic antihistamines significantly cross the blood brain barrier

Answer 26

- no

Question 27

pharmacodynamics issue with Antihistamines

Answer 27

- other pathways may compensate for blockage and build up tolerance

Question 28

important toxicity of Cimetidine which drugs what's the exception to the rule

Answer 28

- drug interactions due to inhibition of CYP enzymes - will reduce their clearance - warfarin - anti-epileptics - theophylline - clopidogrel - doesn't get activated - oral contraceptives

Question 29

importance of theophylline

Answer 29

- low therapeutic index

Question 30

proton pump inhibitor drugs

Answer 30

- omeprazole - esomeprazole - lansoprazole - pantoprazole - rabeprazole

Question 31

MOA of PPIs

Answer 31

- irreversible non competitive antagonist of H+/K+ pump

Question 32

toxicities of PPIs

Answer 32

- C. diff infection - hypomagnesia - vitamin B12 malabsorption - AIN

Question 33

pharmacokinetics issues with PPIs

Answer 33

- pH trapping drives them into secretory canaliculus

Question 34

MOA of Misoprostol

Answer 34

- prostaglandins E2 analog | - inhibits gastric H+ secretion

Question 35

toxicities of Misoprostsal

Answer 35

- promotes abortion of fetus

Question 36

what are some neurotransmitters associated with signals that affect vomiting

Answer 36

- dopamine - serotonin - acetylcholine - neurokinin

Question 37

MOA of Ondansetron what's it used for

Answer 37

- serotonin antagonist | - anti-emetic

Question 38

Toxicities of Odansetron

Answer 38

- prolonged QT interval

Question 39

MOA of Prochlorperazine and promethazine what are they used for

Answer 39

- D2 receptor antagonists | - anti-emetic

Question 40

toxicities of Prochlorperazine and promethazine

Answer 40

- acute dystonia - tardive dyskinesia - prolonged QT

Question 41

for what conditions do you use sucralfate

Answer 41

- GERD (pregnancy)

Question 42

for what conditions to you use antacids

Answer 42

- GERD

Question 43

for what conditions do you use antihistamines

Answer 43

- GERD | - peptic ulcer disease

Question 44

for what conditions do we use PPIs

Answer 44

- GERD - peptic ulcer disease - Zollinger-Ellison syndrome - NSAID associated ulcers - H. pylori eradication

Question 45

for what conditions do we use misoprostol

Answer 45

- NSAID associated ulcers