Pharmacology Flashcards
Drugs for H2 blockers
Cimetidine
ranitidine
famotidine
nizatidine
Mechanism of action of H2 blockers
reversible block of histamine H2-receptors => decrease H+ secretion by parietal cells
Clinical use for H2 blockers
peptic ulcer, gastritis, mild esophageal reflux
Which H2 blockers are associated w/ strong toxicities?
Cimetidine »_space;> Ranitdine»_space;»»»»>famotidine, nizatidine
Name toxicity of Cimetidine
potent inhibitor of cytochrome P-450; antiandrogenic effects (prolactin release, gynecomastia, impotence, decreased male libido) cross BBB (confusion, dizziness, headaches) & placenta;
decrease renal excretion of creatinine
Name toxicity of Ranitidine
decrease renal excretion
Drugs used as proton pump inhibitors
omeprazole lansoprazole esomeprazole pantoprazole dexlansoprazole
mechanism of action of PPIs
irreversibly inhibit H/K ATPase in stomach parietal cells
clinical use of PPIs
peptic ulcer, gastritis, esophageal reflux,
Zollinger-Ellison syndrome
Toxicity of PPIs
increased risk of C. difficile infection, pneumonia;
hip fractures;
decreased serum Mg+ w/ long term use
Chronic use of PPIs will cause a sustained elevation in what GI hormone?
gastrin
What is used to increase ulcer healing?
bismuth or sucralfate
What is used to Tx Sx of traveler’s diarrhea?
bismuth or sucralfate
Mechanism of action for bismuth and sucralfate
bind to ulcer base, providing physical protection and allowing HCO3 secretion to re-establish pH gradient in mucous layer
Mechanism of action for misoprostol
PGE-1 analog =>
increases production & secretion of gastric mucous barrier,
decreases acid production
Clinical use of misoprostol
prevention of NSAID-induced peptic ulcers;
maintenance of patent ductus arteriosus;
used to induce labor => ripens cervix
Toxicity of misoprostol
Diarrhea
Who and why is misoprostol contraindicated for?
contraindicated in women of childbearing potential bc it is an abortifacient
mechanism of action for octreotide
long acting somatostatin analog
clinical use for octreotide
acute variceal bleeds,
acromegaly,
VIPoma,
carcinoid tumors
toxicity of octreotide
nausea, cramps, steatorrhea
Antacid use can affect what?
absorption, bioavailability, or urinary excretion of other drugs by altering gastric and urinary pH or by delaying gastric emptying
All antacids can cause what?
hypokalemia
Overusing an antacid containing aluminum hydroxide can cause what problems?
constipation and hypophosphatemia;
proximal muscle weakness, osteodystrophy, seizures
aluMINIMUM amount of feces
overusing an antacid containing Magnesium hydroxide can cause what problems?
diarrhea, hyporeflexia, hypotension, cardiac arrest
Mg = Must Go to the bathroom
overusing an antacid containing calcium carbonate can cause what problems?
hypercalcemia, rebound acid production
Which antacid formula would most cause absorption, bioavailability, or urinary excretion problems? why?
Calcium carbonate => can chelate and decrease effectiveness of other drugs => tetracycline
What is used as osmotic laxatives?
Mg hydroxide;
Mg citrate;
polyethylene glycol;
lactulose
mechanism of action for osmotic laxatives?
provide osmotic load to draw water out
What drug can be used w/ decrease in neurological ability w/ increased liver failure? How does this work?
lactulose => hepatic encephalopathy;
gut flora degrade lactulose into metabolites (lactic acid & acetic acid) that promote Nitrogen excretion as NH4+
clinical use for osmotic laxatives
constipation
toxicity of osmotic laxatives
diarrhea, dehydration;
abuse by bulimics
mechanism of action for infliximab
monoclonal Ab to TNF-a
clinical use of infliximab
Crohn’s disease, ulcerative colitis, rheumatoid arthritis
toxicity of infliximab
infection => REACTIVATES LATENT TB;
fever;
hypotension
mechanism of action for sulfasalazine
combination of sulfapyridine (antibacterial) and 5-aminosalicylic acid (anti-inflam) => activated by colonic bacteria
clinical use of sulfasalazine
ulcerative colitis, Crohn’s disease
Toxicity of sulfasalazine
malaise,
nausea,
sulfonamide toxicity,
reversible oligospermia
mechanism of action for ondansetron
5-HT3 antagonist=> powerful central acting antiemetic
Keep ON DANCing w/ ONDANSetron
clinical use of ondansetron
control vomiting post-op and in patients undergoing chemotherapy
toxicity of ondansetron
headache, constipation
mechanism of action of metoclopramide
D2 receptor antagonist => increases resting tone, contractility, LES tone, motility => does NOT INFLUENCE colon transport time
clinical use of metoclopramide
diabetic and post-op gastroparesis,
anti-emetic
toxicity of metoclopramide
increase parkinsonian effects;
restlessness, drowsiness, fatigue, depression, nausea, diarrhea
What are drug drug interactions assoc w/ metoclopramide?
digoxin and diabetic agents
Who is metoclopramide contraindicated for?
small bowel obstruction;
parkinson’s disease
Which drugs work on the ulcer bed of the GI?
misoprostol;
sucralfate and bismuth
What drug classes will block parietal cell function by blocking what receptor?
Muscarinic antagonists => block M3-r
H2 blockers => block H2-r
What drug or classes block a receptor on ECL cell to block its release?
Muscarinic antagonist => block M1-r
Octreotide (somatostatin)=> ST-2r
What drug classes work in the stomach lumen and how?
PPI’s inhibit H/K ATPase at apical border of stomach
Antacids => bind H+ in lumen
Misoprostol, sucralfate, bismuth work on ulcers in lumen
