Pharm GI from pharm perspective

Question 1

Role of SNS in GI motility and sphincter tone:
Receptors & effects in Walls?
Receptors & effects in Sphincters?
Secretions?
Prevailing control?

Answer 1

Walls: relaxes, alpha1 & 2
Sphincters: contracts, alpha1
Secretions: no
Prevailing control: no

(probably by inhibition of sympathetics)

Question 2

Role of PNS in GI motility and sphincter tone:
Receptors & effects in Walls?
Receptors & effects in Sphincters?
Secretions?
Prevailing control?

Answer 2

Walls: contracts, M3
Sphincters: relaxes, M3
Secretions: increases, M3
Prevailing control: yes

Question 3

effect of ganglionic blocade in PNS (cholinergic)?

Answer 3

reduced tone/motility. Constipation. Decreased secretions.

Question 4

Role of serotonin:
Other name
Excess & insufficiency results?

Answer 4

Other name: 5-HT
Excess: motility up = D-IBS
Insufficiency: motility down = C-IBS

Question 5

Tegaserod

Answer 5

Partial 5HT-4 agonist, selective serotonin agonist

tx of C-IBS

Withdrawn - heart attack, stroke

Question 6

Treatment of IBS - full agonist/antagonist or partial?

Answer 6

partial, to prevent overtreatment to opposite problem.

Question 7

etiology of IBS

Answer 7

breach of wall -> dendritic cell uptake of antigens -> presentation to T cells, alpha4beta7 integrin adhesion of T cells, CNS signaling -> symptoms

noninflammatory, no ulcers or damage!

Question 8

5 classes of drugs for IBS

Answer 8

stool softeners
antidiarrheal agents
antiplasmotics
TCAs
SSRIs

Question 9

Are probiotics useful in IBS?

Answer 9

Yes, but not high success rates

Question 10

Acupuncture in IBS?
Herbal medicines in IBS?
Psychology in IBS?

Answer 10

Acupuncture in IBS? no
Herbal medicines in IBS? unproven, but promising
Psychology in IBS? not in adults, maybe in adolescents.

Question 11

IBD:
2 examples
etiology
pivotal signaling agent

Answer 11

2 examples: chron’s and ulcerative colitis
etiology: dysbiosis -> inflammation
pivotal signaling agent: TNFalpha

Question 12

4 TNFalpha inhibitors

Answer 12

infliximab
adalimumab
golimumab
certolizumab pegol

Question 13

Treat IBD with TNFalpha inhibs?

Answer 13

Yes, but not front line. 3rd in line. (glucocorticoids, then immunomodulators, then TNFalpha inhibs)

Question 14

3 opioid receptors and their effects

Answer 14

delta: delayed transit

kappa & mu: delayed transit & visceral antinicociception

Question 15

Opioid effects on:
gallbladder
gastroduodenum
small bowel
colon
anorectum

Answer 15

gallbladder: biliary pain, digestion delay
gastroduodenum: anorexia, nausea, emesis
small bowel: constipation, delayed digestion
colon: constipation, bloating, spasms, pain
anorectum: incomplete evacuation, strain

Question 16

5 types of drug induced diarrhea

Answer 16

osmotic
secretory
disordered (cholinergic tone)
inflammatory (flora disruption)
C difficile (acid/base or epithelial homostasis)
Fatty

Question 17

metformin side effect

Answer 17

steatorrhea

Question 18

octreaotride side effect

Answer 18

paradoxical steatorrhea (treats secretory d)

Question 19

drugs to avoid in pill-induced esophagitis?

Answer 19

anticholinergics

Question 20

role of P-gp/MDR1

Answer 20

dramatically increases drug bioavailability

Question 21

role of cyp3A4 vs P-gp/MDR1?

Answer 21

P-gp/MDR1 may control CYP3A4

Question 22

4 notorious drugs with gastric interactions

Answer 22

antacids, doxycycline, tetracycline, fluoroquinolones

Question 23

cimetidine AE WRT PPIs

Answer 23

inhibits tons of cyps

Question 24

PPIs metabolism

Answer 24

CYP2C19

all but dexlansoprazole inhibit 2C19

Question 25

dexlansoprazole

Answer 25

doesn’t inhibit CYP2C19