World - GI

Question 1

Bethanechol

Answer 1

Cholinomimetic muscarinic agonist
* Rx for ileus & urinary retention
* promotes gastric acid secretion via stimulation of parietal cell M3 receptors

Question 2

Atropine

Answer 2

Non-selective anti-muscarinic agent
* produces mydriasis & cycloplegia
* reverses bradycardia
* may reduce gastric acid secretion (via vagal stimulation) by blocking parietal cell M3 receptors

Question 3

What nutrients will CF patient (w/ pancreatic insufficiency) absorb better on PPI?

Answer 3

Dietary fats.
* Lipase enzyme replacement will be less inactivated by the acidic environment of the stomach

Question 4

Worse absorption of which nutrients on PPI?

Answer 4

1. Calcium (osteoporosis)
2. Iron
3. Magnesium
4. Vitamin B12

Question 5

PPIs have which adverse effects?

Answer 5

1. C. diff infection, pneumonia (increased infection risk)
2. Osteoporosis
3. CKD
4. SIBO

Question 6

Hyperlipidemia drug avoided in gallbladder disease patients:

inhibits 7-a-hydroxylase

Answer 6

Gemfebrozil (fibrates)
* reduced bile acid synthesis
* decreased cholesterol solubility
* promotes gallstone formation

Also fenofibrate

Question 7

Niacin (B3)

Answer 7

Increases HDL & lower triglyceride levels (inhibition of VLDL secretion)
* lower rates of gallstone disease
* adverse = flushing (Rx = NSAIDs)

Question 8

Infliximab, Adalimumab

TNF-a inhibitors

Answer 8

TNF-a inhibitors
* first-line for Crohn Disease
* non-caseating granulomas
* skip lesions, spares the rectum

Question 9

Imatinib

Answer 9

BCR-ABL protein TK inhibitor
* first line treatment CML
* translocation between chromosomes 9 & 22

Question 10

Rituximab

Answer 10

CD-20 target MAB
* Rx for autoimmune disorders (RA)
* results in B-cell depletion

Question 11

Sirolimus

Answer 11

mTOR inhibitor
* patients with solid organ transplant
* preventing allograft rejection

NOT nephrotoxic !! OMG

Question 12

• Nivolumab
• Pembrolizumab

PD-1 inhibitors

Answer 12

Cancer immunotherapy drugs used to stimulate an immune response against cancer cells
* PD-1 is an immune checkpoint molecule that downregulates the immune response

Question 13

Cholestyramine’s effects on hepatic cholesterol synthesis

Sequence of events

Answer 13

INCREASES
Bile acid-binding resins
1. Bind bile acids in the GI tract
2. Interfere with enterohepatic circulation of bile acids&raquo_space; cause increased bile acid excretion
3. Results in NEW hepatic synthesis of bile aids
4. Process uses intrahepatic cholesterol stores
5. Hepatic uptake of LDL from circulation is increased for continued bile acid synthesis
6. Bile acid production & secretion are increased 10x due to the interruption of enterohepatic circulatioin
7. Hepatic cholesterol is reduced – so activates HMG CoA reductase
8. More hepatic cholesterol is synthesized

Question 14

Statin’s effect on hepatic cholesterol synthesis

Answer 14

DECREASES
* drug competitively inhibits HMC-CoA reductase
* Result = upregulation of LDL receptors, causing increased uptake of LDL from circulation
* very effective at reducing serum LDL cholesterol

Question 15

Role of dextrose in oral rehydration solution

Answer 15

Enhancement of sodium absorption

Question 16

Oral rehydration solution components

Answer 16

Question 17

Hepatic encephalopathy

Answer 17

Neuro complication of cirrhosis
* altered mental status
* asterixis – rhythmic flapping of hands

Risk factors
* GI bleeding
* Excess dietary protein intake

Question 18

Rifamixin

Answer 18

Rx for hepatic encephalopathy

Antibiotic that alters GI flora
* decrease production/absorption NH4
* add to lactulose (lowers the colonic pH – more convert ammonia to ammonium)

Question 19

• Bisacodyl
• Senna

Stimulant laxatives

Answer 19

Improves peristalsis by stimulating the enteric nerves (myenteric plexus)
Side effects
* abdominal cramping
* electrolyte disturbances

Question 20

The osmotic laxatives?

Answer 20

1. Polyethylene glycol
2. Magnesium hydroxide
3. Lactulose

Question 21

Non-operative management of calculous cholecystitis

Answer 21

Bile acid supplementation
* Reduces gallstone formation – via increased solubility

Question 22

Meds associated with constipation

Answer 22

Question 23

Patient who developed constipation after new-onset atrial fibrillation:

Answer 23

non-DHR calcium channel blockers
* Diltiazem
* Verapamil

Question 24

Neostigmine

Answer 24

Cholinesterase inhibitor
* Increases cholinergic stimuli

Question 25

Pilocarpine

Answer 25

Cholinergic agonist
* Increases cholinergic stimuli

Question 26

Anti-emetic drugs

Answer 26

Question 27

Erthyromycin

Answer 27

Motilin receptor agonist
* Used for gastroparesis (can be caused be diabetic diarrhea)