PHARM_OVERVIEW

Question 1

what is the predominant tone of the GI system?

Answer 1

parasympathetic (cholinergic)

Question 2

what is the effect of ganglionic blockade of the parasympathetic nervous system in the GI tract?

Answer 2

reduced tone & motility
constipation
decreased gastric and pancreatic secretions

Question 3

what is DUMBBELLS

Answer 3

Diarrhea
Urination
Miosis (constriction of pupil) /muscle weakness
Bronchorrhea
Bradycardia
Emesis
Lacrimation
Sweating

Question 4

what is the probable role of Ach in the GI nervous system?

Answer 4

a primary excitatory transmitter to smooth muscle and secretory cells in the ENS. Probably also the major neuron-to-neuron ganglionic transmitter in the ENS

Question 5

what is the role of dopamine in the GI nervous system?

Answer 5

A modulatory transmitter in the ENS

Question 6

what is the role of Enkephalin and related opioid peptids in the GI nervous system?

Answer 6

present in some secretomotor and interneurons in ENS. Inhibits ACh release & peristalsis. May stimulate secretion

Question 7

what is the function of serotonin in the GI nervous system?

Answer 7

an important transmitter or cotransmitter at excitatory neuron to neuron junctions in the ENS

Question 8

what is metoclopramide, and what is it used for?

Answer 8

used to treat N/V and has gastrokinetic actions

-results in coordinated contractions that enhance transit

Question 9

the effects of metoclopramide are limited to what part of the GI tract?

Answer 9

upper GI, where it increases LES tone & stimulates antral & small intestinal contractions

Question 10

what is one of the proposed explanations for the etiology of irritable bowel syndrome?

Answer 10

serotonin disequilibrium

• excess 5-HT–>D-IBS
• insufficient 5-HT–> C-IBS

Question 11

what kind of serotonin antagonist would you want to use that would normalize the activity rather than totally override the activity?

Answer 11

a weak partial agonist

Question 12

what are the pharmacologic treatments of constipation in IBS?

Answer 12

stool softeners

Question 13

what are the pharmacologic treatments of diarrhea in irritable bowel syndrome?

Answer 13

antidiarrheal agents

Question 14

what are the pharmacologic treatments of abdominal pain and discomfort in Irritable bowel syndrome?

Answer 14

antispasmodics
TCAs
SSRIs

Question 15

how can probiotics improve management of IBS?

Answer 15

can improve barrier function of epithelium, inhibit pathogenic bacteria, acidify colon, improve dysmotility

Question 16

what is the explanation for the etiology of IBD?

Answer 16

dysbiosis of normal intestinal homeostatic relationship b/w intestinal mucosa and normal microbiome–>inflamm. rxn

Question 17

whats the name of the TNF-alpha blocker that block TNF-alpha1, TNF-alpha2, and soluble TNF-alpha receptors?

Answer 17

infliximab

Question 18

what are the clinical effects of opioids on the gallbladder?

Answer 18

biliary pain, delayed digestion

Question 19

what are the clinical effects of opioids on the gastroduodenum?

Answer 19

anorexia, nausea, emesis

Question 20

what are the clinical effects opioids on the small bowel?

Answer 20

constipation, delayed digestion, hard, dry stool

Question 21

what are the clinical effects of opioids on the colon?

Answer 21

constipation, hard, dry stools, bloating & distension, spasm, cramps, pain

Question 22

what are the clinical effects of opioids on the anorectum?

Answer 22

incomplete evacuation, straining constipation

Question 23

How can drugs cause osmotic diarrhea?

Answer 23

caused by medications that draw water into the GI tract

Question 24

How can drugs cause secretory diarrhea?

Answer 24

caused by meds that impair Na+ absorption & Cl- & HCO3 ions ar esecreted into the GI lumen

Question 25

how can drugs cause disordered motility?

Answer 25

drugs affecting cholinergic tone

Question 26

how can drugs cause inflammatory diarrhea?

Answer 26

disruption of colonic flora precipitating C. Diff colitis, or following direct damage of the gastric mucosa

Question 27

how can drugs cause C. Diff diarrhea?

Answer 27

drugs that disrupt acid-base environment or epithelial homeostasis or immune system function

• PPIs, H2 antagonists, & immunosuppressants
• NSAIDS: direct epithelial damage & +/- Na+ perm.

Question 28

how can drugs cause fatty diarrhea (steatorrhea)?

Answer 28

orlistat & alli
metformin–> decrease Glucose absorption
Octreotide–>paradoxical fatty diarrhea

Question 29

what kind of pts get pill-induced esophagitis?

Answer 29

old pts

Question 30

what is pill-induced esophagitis?

Answer 30

a feeling that pill is stuck in throat: pts may complain of burnin and retrosternal pain
-damage usually heals in days, but can lead to esophageal perf., hemorrhage, & death

Question 31

what are the drug risk factors related to pill-induced esophagitis?

Answer 31

prescription of gelatin capsules, and ER or sustained released products

Question 32

what class of drugs must you avoid if you have a pt with pill-induced esophagitis?

Answer 32

anticholinergics

Question 33

what 2 enzymes are the major regulator s of drug bioavailability?

Answer 33

P-GP/MDR & CYP3A (participate in 1st pass metab. in the intestinal wall)

Question 34

antacids can chelate which class of drugs?

Answer 34

Doxycycline, tetracycline, most fluoroquinolones

Question 35

which class of drugs can cause constipation or diarrhea and can alkalinize the urine?

Answer 35

antacids

Question 36

all proton pump inhibitors are substrates of what CYP enzyme?

Answer 36

CYP2C19