GI Drugs Flashcards by lauren Poe

H2 blockers

Cimetidine, Ranitidine, Famotidine, Nizatidine

*Take before you DINE, Table for 2”

How well did you know this?

Not at all

Perfectly

Mechanism of H2 blockers

reversibly block histamine (H2) receptors on parietal cell

decreases H+ secretion by parietal cells

How well did you know this?

Not at all

Perfectly

Clinical use of H2 blockers

peptic ulcer
gastritis
mild GERD

How well did you know this?

Not at all

Perfectly

toxicity of H2 blockers

Most H2 blockers are relatively free of S/E
Ranitidine– decreases renal excretion of creatinine

Cimetidine–
potent inhibitor of p450 = multiple drug interactions
antiandrogenic effects (inc PRL release = gynecomastia, impotence & dec libido in males)
can cross BBB (confusion, dizzy, HA) & placenta
decreases renal excretion of creatinine

How well did you know this?

Not at all

Perfectly

Proton Pump Inhibitors

Omeprazole
lansoprazole
pantoprazaole
esomeprazole
dexlansoprazole

(-prazole)

How well did you know this?

Not at all

Perfectly

Mechanism of PPI’s

irreversibly inhibit H/K ATPase in stomach parietal cells

How well did you know this?

Not at all

Perfectly

Clinical use of PPIs

Peptic Ulcer
Gastritis
GERD
Zollinger-Ellison syndrome

How well did you know this?

Not at all

Perfectly

toxicity of PPIs

inc risk of C. diff infxn & pneumonia
Hip fx
dec serum Mg with long-term use

How well did you know this?

Not at all

Perfectly

Bismuth & Sucralfate MOA

bind to ulcer base = physical protection

allows HCO3 secretion to re-establish pH gradient in the mucus layer

How well did you know this?

Not at all

Perfectly

clinical use of bismuth & sucralfate

traveler’s diarrhea

ulcer healing

How well did you know this?

Not at all

Perfectly

Misoprostol MOA

PGE1 analog (prostaglandin)
increases production & secretion of gastric mucous barrier
decreases acid production

How well did you know this?

Not at all

Perfectly

clinical use of Misoprostol

prevents NSAID-induced peptic ulcers
maintains PDA
induces labor (ripens cervix)

How well did you know this?

Not at all

Perfectly

Toxicity of Misoprostol

Diarrhea

CONTRA if childbearing potential (abortifacient)

How well did you know this?

Not at all

Perfectly

Octreotide MOA

long-acting somatostatin analog (inhibits GF)

How well did you know this?

Not at all

Perfectly

Clinical use of Octreotide

Acute variceal bleeds
VIPoma
carcinoid tumor

(and tx acromegaly)

How well did you know this?

Not at all

Perfectly

toxicity of Octreotide

nausea, cramps, steatorrhea

How well did you know this?

Not at all

Perfectly

Antacid types

Aluminum Hydroxide
Magnesium Hydroxide
Calcium Carbonate

How well did you know this?

Not at all

Perfectly

MOA & S/E of all antacids

affects absorption, bioavailability or urinary excretion of other drugs by altering gastric & urinary pH, or by delaying gastric emptying.
causes hypokalemia

How well did you know this?

Not at all

Perfectly

Aluminum hydroxide S/E

constipation (MINIMUM feces)
hypophosphatemia
proximal muscle weakness
osteodystrophy
seizures

Magnesium hydroxide S/E

Diarrhea (Must Go)
hyporeflexia
hypotension
cardiac arrest

Calcium carbonate S/E

hypercalcemia
rebound acid increase
decreases other drug effectiveness (chelates)– esp tetracycline

Osmotic Laxatives

magnesium hydroxide
magnesium citrate
polyethylene glycol
lactulose

MOA of osmotic laxatives

provide osmotic load = draws water out into lumen
lactulose also treats hepatic encephalopathy– since gut flora degrade it into metabolites of lactic acid & acetic acids (promote nitrogen excretion as NH4+)

clinical use of osmotic laxatives

constipation

toxicity of osmotic laxatives

diarrhea dehydration *abused by bulimics

Infliximab MOA

monoclonal antibody to TNF-alpha | -mab = monoclonal Ab

use of Infliximab

Crohn's Dz Ulcerative colitis Rheumatoid arthritis

Toxicity of Infliximab

infection (reactivation of latent TB) fever hypotension

Sulfasalazine MOA

combo of sulfapyridine (antibacterial) & 5-aminosalicylic acid (anti-inflammatory) activated by colonic bacteria

Use of Sulfasalazine

Ulcerative Colitis | Crohn's

Toxicity of Sulfasalazine

Malaise Nausea reversible oligospermia sulfonamide toxicity

Ondansetron MOA

5-HT3 antagonist | powerful centrally-active antiemetic

Clinical Use of Ondansetron

control vomiting postop | chemotherapy pts

S/E of Ondansetron

HA, constipation

Metoclopramide MOA

D2 receptor antagonist increases resting tone, contractility, LES tone, motility. does NOT influence colon transport time

Clinical use of Metaclopramide

Diabetic Post-surgery gastroparesis Antiemetic

Toxicity of Metaclopramide

Inc parkinsonian effects restlessness, drowsiness, fatigue, depression, nausea, diarrhea *drug interaction w/ digoxin & diabetic tx *CONTRA in pts with small bowel obstruction & parkinson's disease

What is octreotide used for?

Esophageal varices

How does octreotide work in treating esophageal varices?

Decreases glucagon and VIP which vasodilate splanchnic vessels. Causes vasoconstriction of splanchnic vessels thereby diverting blood flow to the systemic circulation. Does not cause systemic circulation vasoconstriction

What is pentagastrin?

A gastrin analog used to screen for carcinoid syndrome and medullary carcinoma of the thyroid

What over the counter drug may reduce the risk of adenomatous polyp formation in the colon?

aspirin - some colon adenomas have shown over expression of COX2

What is diphenoxylate?

An opiate anti-diarrheal structurally related to meperidine.

What is the MOA of diphenoxylate?

Binds mu receptors in the GI tract and causes slower motility.

What are the side effects of diphenoxylate?

Bloating and mild sedation | Can cause euphoria and physical dependence

What is diphenoxylate combined with to prevent abuse?

Atropine - causes dry mouth, blurry vision and nausea at higher doses. Atropine + diphenoxylate = lomotil

What are the drugs that target secretory diarrhea?

Bismuth salicylate Probiotics Octreotide