GI pharm

Question 1

What are the H2 blockers?

Answer 1

Cimetidine, ramitidine, famotidine, nizatidine

Question 2

H2 blockers mech

Answer 2

Reversible block of histamine H2 receptors which decreases H+ secretion by parietal cells

Question 3

Clinical use of H2 blockers

Answer 3

Peptic ulcer, gastritis, mild esophageal reflux

Question 4

What is the H2 blocker with the most SE/Toxicity, and what are the SE?

Answer 4

Cimetidine is a potent inhibitor of CYP-450 (multiple drug interactions); it also has antiandrogenic effects (prolactin release, gynecomastia, impotence, decreased libido in males); can cross blood-brain barrier (condusion, dizziness, headaches) and placenta. Both cimetidine and ranitidine decrease renal excretion of creatinine. Other H2 blockers are relatively free of these effects.

Question 5

What are the PPI’s?

Answer 5

Omeprazole, Lansoprazole, esomeprazole, pantoprazole, dexlansoprazole.

Question 6

What is the mech of PPI?

Answer 6

Irreversibly inhibit H+/K+ ATPase in stomach parietal cells

Question 7

What is the clinical use of PPIs?

Answer 7

peptic ulcer, gastritis, esophageal reflux, Zollinger-Ellison syndrome

Question 8

Toxicity of PPIs?

Answer 8

Increased risk of C. Diff infection, pneumonia. Hip fractures, decreased serum Mg+2 with long-term use

Question 9

What is the mech of Bismuth, Sucralfate

Answer 9

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

Question 10

What is the clinical use opf Bismuth, Sucralfate

Answer 10

Increase ulcer healing, travelers’ diarrhea

Question 11

Misoprostol mech

Answer 11

A PGE1 analog. Increased production and secretion of gastric mucous barrier, decreases acid production

Question 12

What is the clinical use of Misoprostol?

Answer 12

Prevention of NSAID induced peptic ulcers (NSAIDs block PGE1 production); maintenance of a PDA. Also used to induce labor (ripens cervix)

Question 13

Octreotide mech

Answer 13

Long-acting somatostatin analog.

Question 14

Clinical use of Ostreotide?

Answer 14

Acute variceal bleeds, acromegaly, VIPoma, and carcinoid tumors.

Question 15

Toxicity of Octreotide?

Answer 15

Nausea, cramps, steatorrhea

Question 16

What are the Antacids?

Answer 16

Aluminum Hydroxide, Calcium Carbonate, Magnesium Hydroxide.

Question 17

What are the Antacids used for?

Answer 17

Can affect absorption, bioavailability, or urinary excretion of other drugs by altering gastric and urinary pH or by delaying gastric emptying. All can cause hypokalemia. Overuse can also cause the following problems

Question 18

Aluminum Hydroxide SE?

Answer 18

Constipation and hypophosphatemia; proximal muscle weakness, osteodystrophy, seizures. aluMINIMUM amount of feces

Question 19

Calcium Carbonate SE?

Answer 19

Hypercalcemia, rebound acid increase! Can chelate and decrease effectiveness of other drugs (i.e. tetracycline)

Question 20

Magnesium Hydroxide SE?

Answer 20

Diarrhea, hyporeflexia, hypotension, cardiac arrest. Mg=Must Go to the bathroom

Question 21

What are the Osmotic laxatives?

Answer 21

Magnesium hydroxide, magnesium citrate, polyethylene glycol, lactulose.

Question 22

What is the mech of Osmotic Laxatives?

Answer 22

Provide osmotic load to draw water out. Lactulose also treats hepatic encephalopathy since gut flora degrade it into metabolites (lactic acid and acetic acid) that promote nitrogen excretion as NH4+

Question 23

What is the clinical use of Osmotic Laxatives?

Answer 23

Constipation

Question 24

What is the toxicity of Osmotic Laxatives?

Answer 24

Diarrhea, dehydration; may be abused by bulimics

Question 25

What is the mech of Infliximab?

Answer 25

monoclonal antibody to TNF-alpha

Question 26

Clinical use of Infliximab?

Answer 26

Crohn disease, ulcerative colitis, rheumatoid arthritis, ankylosing spondylitis, psoriasis

Question 27

Toxicity/SE of Infliximab?

Answer 27

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

Question 28

Sulfasalazine mech

Answer 28

A combination of sulfapyridine (antibacterial) and 5-aminosalicyclic acid (anti-inflammatory). Activated by colonic bacteria.

Question 29

What is the clinical use of Sulfasalazine?

Answer 29

Ulcerative Colitis, Crohn disease.

Question 30

What is the SE/Toxicity of Sulfasalazine

Answer 30

Mailaise, nausea, sulfonamide toxicity, reversible oligospermia.

Question 31

Mech of Ondansetron

Answer 31

5-HT3 antagonist; decreased vagal stimulation. Powerful central-acting antiemetic.

Question 32

Clinical use of Ondansetron

Answer 32

Control vomiting postoperatively and in patients undergoing cancer chemotherapy.

Question 33

SE/Toxicity of Ondansetron

Answer 33

Headache, constipation

Question 34

Metoclopramide mech?

Answer 34

D2 receptor antagonist. increase resting tone, contractility, LES tone, motility. Does not influence colon transport time.

Question 35

Clinical use of Metoclopramide?

Answer 35

Diabetic and post surgery gastroparesis, antiemetic

Question 36

Toxicity/SE of Metoclopramide?

Answer 36

Increased parkinsonian effects. Restlessness, drowsiness, fatigue, depression, nausea, diarrhea. Drug interction with digoxin and diabetic agents. Contraindicated in patients with small bowel obstruction or Parkinson disease (D1 receptor blockade)