GI Drugs Flashcards Preview

USMLE Step 1 > GI Drugs > Flashcards

Flashcards in GI Drugs Deck (37):
1

H2 blockers

end in "-tidine"
Cimetidine
Ranitidine
Famotidine
Nizatidine

2

H2 blockers: Mechanism

Reversible block of histamine (H2-receptors) -- leads to decrease in H+ secretion by parietal cells

3

H2 blockers: Clinical Use

Peptic Ulcer, Gastritis, mild esophageal reflux

4

H2 blocker Toxicity:

Cimitidine has a lot of side effects
-Potent inhibitor of P-450 (higher concentrations of other drugs)
- Has anti-androgenic effects (prolactin release, gynecomastia, impotence, decrease libido in males)
- Can cross blood-brain barrier (confusion, dizziness, headaches) and placenta
- Both cimitidine and ranitidine decrease renal excretion

5

Proton Pump Inhibitors

Omeprazole, Lansoprazole, Esomeprazole, Pantoprazole, Dexlansoprazole

6

Proton Pump Inhibitors ("-prazole"): Mechanism

Irreversibly inhibit H/K/ATPase in stomach parietal cells

7

Proton Pump Inhibitors ("-prazole": Clinical Use

Peptic ulcer, Gastritis, Esophageal Reflux, Zollinger- Ellison syndrome

8

Proton Pump Inhibitors ("-prazole"): Toxicity

Increased risk of C. difficile infection, pneumonia. Hip fractures,
- Decreased serum Mg with long term use

9

Bismuth, Sucralfate: Mechanism

Bind to ulcer base, providing physical protection and allowing HCO3 secretion to re-establish pH gradient in mucous layer

10

Bismuth, Sucralfate: Clinical Use

Increase ulcer healing, traveler's diarrhea

11

Misoprotol: Mechanism

A PGE-1 analog. Increase production and secretion of gastric mucous barrier. Decrease acid production

12

Misoprotol: Clinical Use

Prevention of NSAID induced peptic ulcer; maintenance of PDA.
- Also used to induce labor (ripens cervix)

13

Misoprotol: Toxicity

Diarrhea. Contraindicated in women of childbearing potential (abortificatin)

14

Octeotride: Mechanism

Long-acting somatostatin analog

15

Octeotride: Clinical Use

Acute variceal bleeds, acromegaly, VIPoma and carcinoid tumors

16

Octeotride: Toxicity

Nausea, cramps, steatorrhea

17

Antacid Use

- Can affect absorption, bioavailability or urinary excretion of other drug by altering urinary pH or delaying gastric emptying
- All can cause HYPO-kalemia

18

Aluminum hydroxide

Antacid
- Can cause constipation and HYPOphosphatemia; proximal muscle weakness, osteodystrophy, seizures

**AluMINIMUM amount of feces"

19

Magnesium hydroxide

Antacid
- can cause diarrhea, HYPOreflexia, HYPOtension, Cardiac arrest
"Think Milk of Magnesia (laxative)
** Mg = Must Go to the bathroom

20

Calcium carbonate

Hypercalcemia, Rebound acid increase

21

Osmotic laxatives

Magnesium Hydroxide, Magnesium Citrate, Polyethylene glycol, Lactulose

22

Oxsmotic laxatives: Mechanism

Provide osmotic load to draw water out

23

Discuss lactulose and hepatic encephalopathy

Lactulose treats hepatic encephalopathy since gut flora degrades it into metabolites (lactic acid and acetic acid) that promote nitrogen excretion as NH4

24

Osmotic laxative: Clinical Use

Constipation

25

Osmotic laxative: Toxicity

Diarrhea, dehydration, may be abused by bulimics

26

Infliximab: Mechanism

Monoclonal antibody to TNF-alpha

27

Infliximab: Clinical Use

Crohn's disease, UC, Rheumatoid arthritis

28

Infliximab: Toxicity

Infection (including reactivation of latent TB), fever, hypotension

29

Sulfasalazine: Mechanism

A combination of sulfapyridine (anti-bacterial) and 5-aminosalicylic acid (anti-inflammatory)
- Activated by colonic bacteria

30

Sulfasalazine: Clinical USe

UC, Crohn's disease

31

Ondanestron: Mechanism

5-HT3 antagonist. Powerful central-acting anti-emetic.

32

Ondansetron: Clinical Use

Control vomiting postoperatively and in patients undergoing cancer chemotherapy

33

Ondansetron: Toxicity

Headache, constipation

34

Sulfasalazine: Toxicity

Malaise, nausea, sulfonamide toxicity, reversible oligospermia

35

Metoclopramide

D2 receptor antagonist
- Increase resting tone, contractility, LES tone, motility
- Does not influence colon transport time

36

Metoclopramide: Clinical USe

Diabetic and post-surgery gastroparesis, anti-emetic

37

Metoclopramide: Toxicity

Increase in parkinosonian effects
- Restlessness, drowsiness, fatigue, depression, nausea, diarrhea
- Drug interaction with digoxin and diabetic agents
- Contraindicated in patient with small bowel obstruction or Parkinson's disease