Prokinetics

Question 1

What are the cholinomimetics used to treat constipation?

Answer 1

Cisapride
Domperidone
Metoclopramide

Question 2

What are the MoAs of cisapride?

Answer 2

5-HT4 agonist

Partial 5-HT3 antagonist

Question 3

What is a major side effect of cisapride?

Answer 3

Cardiac arrhythmias

Drug is restricted

Question 4

What is the MoA of domperidone?

Answer 4

D2 receptor antagonist –> inhibition of the inhibition of ACh-induced contraction

Question 5

Does domperidone effect brain dopamine receptors?

Answer 5

No…does not cross BBB

Question 6

What is the MoA of metocopramide?

Answer 6

D2 receptor antagonist –> inhibition of the inhibition of ACh-induced contraction

Question 7

Does metocompramide effect brain dopamine receptors?

Answer 7

Yes…prevents vomiting…possibly prevents hiccups

Question 8

What are the side effects of domperidone?

Answer 8

Somnolence, nervousness, agitation, and anxiety
Dystonia, Parkinsonism, and tardive dyskinesia
Increased pituitary prolactin release (impotence, galactorrhea, menstrual disorders)

Question 9

What is the MoA of macrolides treating constipation?

Answer 9

Macrolides stimulate motilin receptors on GI smooth muscle –> initiation of MMC

Question 10

Are macrolides often used to treat constipation?

Answer 10

Not really…resistance to the drug develops