GI Drugs Flashcards
H2 blockers, -tidines
reversible block of H2 receptors, decreasing H+ secretion by parietal cells
use: peptic ulcers, gastritis, esophageal reflux
tox:
cimetidine is a P450 inducer, and has anti-androgenic effects, can cross BBB and the placenta causing CNS symptoms, decreases creatinine excretion
PPIs, -prazoles
irreversibly inhibit H/K ATPase in stomach parietal cells
use: peptic ulcer, gastritis, esophageal reflux, ZE syndrome, post severe burns (Curling ulcer)
tox: risk of C diff, pneumonia, hip fractures, decreased serum Mg with long term use
Bismuth, sucralfate
bind to an ulcer base, providing physical protection and allowing bicarb to establish normal pH gradient
use: allow for ulcer healing, traveler’s diarrhea
Misoprostol
PGE1 analog, increased production of gastric mucus barrier and decreased acid production
use: prevention of NSAID induced peptic ulcers, kEEEEps PDA open, labor induction
tox: diarrhea, contraindicated in women trying to become preganant
Octreotide
long acting somatostatin analog
use: acute variceal bleeding, acromegaly, VIPoma, carcinoid tumors
tox: nausea, cramps, steatorrhea
Antacids - General
Can affect absorption, bioavailability, excretion of drugs by alterting pH in gastric lumen or urine
ALL CAN CAUSE HYPOKALEMIA
Aluminum Hydroxide
used as an antacid
tox: constipation, hypophosphotemia, proximal muscle weakness, osteodystrophy, seizures
Calcium carbonate
used as an antacid
tox: hypercalcemia, rebound acid increase, can chelate other drugs (tetracyclines)
Magnesium hydroxide
used as an antacid
tox: diarrhea, hyporeflexia, hypotension, cardiac arrest
Name some drugs used as osmotic laxatives?
magnesium hydroxide, magnesium citrate, polyethelene glycol, lactulose
Lactulose
osmotic laxative
acidifies the gut lumen, used for hepatic encephalopathy; traps NH3 in the gut as NH4+
Infliximab
monoclonal antibody against TNF-alpha
use: Crohn’s, UC, RA, ankylosing spondylitis, psoriasis
tox: infection; ALWAYS check for latent TB
Sulfasalazine
Combination sulfapyridine (antibacterial) and 5-aminosalicylic acid (anti-inflammatory); activated by colonic bacteria
used in UC and Crohn’s
tox: sulfa allergy, oligospermia
Ondansetron
5-HT3 antagonist, decreases vagal stimulation
centrally acting anti-emetic
tox: headache, constipation
Metoclopramide
D2 receptor antagonist; increases resting tone, contractility, LES tone, motility (no effect on colon)
use: diabetic and post-surgical gastroparesis, antiemetic
tox: parkinsonian effects
