Module 3: IBS and Nausea, Vomiting - Dr. Covert

Question 1

What is the Rome IV Criteria?

Answer 1

used to stage IBS

-recurrent abdominal pain at least 1 day/week in the last 2 months with 2+:
related to defecation
change in frequency of stool
change of form/appearance of still

4 types: IBS-Constipation, IBS-Diarrhea, IBS-unclassified, IBS-mixed

Question 2

Definition of IBS

Answer 2

Simplified:
abdominal discomfort with changes in bowel habits

Question 3

How does serotonin affect gut motility?

Answer 3

-more serotonin -> more gut motility -> diarrhea
-less serotonin -> less gut motility

Question 4

Which diseases should be ruled out when treating IBS-D?

Answer 4

-Celiac disease
-Inflammatory Bowel Disease (IBD) (Chron’s disease, Ulcerative colitis)

-testing for allergies to food is not recommended (pt might stop eating food if they have minor allergies and not causing the symptoms)

Question 5

OTC agents for IBS-Constipation

Answer 5

-PEG derivatives (MiraLax, GlycoLax, PEGyLAX}
-Stool softeners (Docusate)

-Stimulant Laxative (Senna, Bisacodyl)
->ADR: cramping

Question 6

What are the prosecretory agents

Answer 6

-Linaclotide (Linzess)
-Plecanatide (Trulance)

Lubiprostone (Amitizia)

Question 7

Which of the prosecretory agents work by Stimulation of guanylate cyclase-C

Answer 7

-Linaclotide (Linzess)
-Plecanatide (Trulance)

-chloride and bicarbonate secretion into the intestinal lumen
-enhanced intestinal secretion and gastric transit

Question 8

Contraindications for Linaclotide and Plecanatide

Answer 8

-Contraindicated in patients < 6 y/o,
-avoid use in patients 6-17 y/o secondary to severe dehydration

-it might work too well causing diarrhea and fluid loss

Question 9

MOA for Lubiprostone (Amitiza)

Answer 9

-Chloride Channel Type-2 Activator
-water flux into intestinal lumen -> increased
gastric transit

-NOT approved for use in men
-Dosing: 8 mcg po BID

Question 10

Which laxative to use for male patients

Answer 10

Linaclotide
Plecanatide

Question 11

How does Tegaserod work?

Answer 11

-5-HT4 Agonist
-Stimulation of 5-HT4 Receptors
-stimulates peristalsis
-enhances intestinal secretion
-increases gastric transit

Question 12

What are the opioid agonists used in IBS-D?

Answer 12

-Loperamide (Imodium)
-Diphenoxylate/Atropine (Lomotil)

Question 13

Which drug to avoid in patients with SUD?

Answer 13

Opioid agonists: Loperamide?
-Eluxadoline (Viberzi)
-100 mg PO BID

ADR: CNS depression (somnolence not depression), potential dependence, pancreatitis, hepatotoxicity

Question 14

When to use Rifaximin (Xifaxin)

Answer 14

-antibiotic, blocking bacterial RNA polymerase

-block bacterial or fungal growth
-550 mg PO TID 14 days

Question 15

Why might 5HT3 antagonists be not preferred in IBS-D?

Answer 15

-MOA: blocks serotonin receptors in the gut -> slows motility

-it can cause ischemic colitis (GI stops working)
-only for females
-0.5 mg po BID for 4 weeks

Question 16

Role of TCA in IBS-D

Answer 16

-3rd to 4th line
-actually used for anxiety and depressing
-with strong anticholinergic effects (dry mouth, dry eyes, constipation)

Question 17

Which drug is contraindicated in patients with more than 1 cardiovascular risk factor?

Answer 17

Tegaserod (Zelnorm)

Question 18

Which drugs to use for motion sickness?

Answer 18

Antihistamines
-Diphenhydramine (benadryl)
-Meclizine (Antivert)

Anticholinergics
-Scopolamine (Maldemar) - doesn’t work quickly
applied behind the ear, 4 h before exposure, every 3 days

Question 19

Which drug is approved for pregnancy N/V

Answer 19

Doxylamine/ Pyridoxine (Diclegis)

Question 20

Which antiemetic drug causes QTc prolongation

Answer 20

5HT3 antagonist
-Ondansetron
-Palonosetron
-Granisetro

Question 21

Which drugs are used for chemotherapy-induced nausea?

Answer 21

Combination
-NK-1 antagonists:
Aprepitant (Emend)
Fosaprepitant (Emend)
Netupitant/palonosetron (Akynezo)

-Steroids: Dexamethasone (Decadron)

-5HT3 antagonists (“setrons”)

Question 22

When are dopamine antagonists used?

Answer 22

-blocks dopamine receptors in the gut
-it causes the gut to move more quickly

-used in gastropareses (often in T2DM, where nerves stop working)

-Metoclopramide (Reglan)
-Prochlorperazine (Compazine) - acute N/V

ADR: EPS (extra-pyramidal symptoms - movement disorder)