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51 Cards in this Set
- Front
- Back
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What are some H2 blockers?
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cimetidine
ranitidine famotidine nizatidine |
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What is the mechanism of cimetidine?
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reversible block of histamine H2 RECEPTORS on parietal cells, and this prevents H2 secretion by parietal cells.
COMPETITIVE ANTAGONISTS B/C THEY ARE REVERSIBLE |
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What are the clinical usage for cimetidine (H2 blocker)?
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Peptid ulcer, gastritis, mild esophageal reflux, ZE syndrome, stress ulcers.
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What is the toxicity of cimetidine?
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Is a potentnt INHIBITOR of P450 and has antiandrogenic effect (leads to gynecomastia and galactorrhea)
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What are some examples of proton pump inhibitors?
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1) Omeprazole
2) Lansoprazole |
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What is the action of omeprazole?
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IRREVERSIBLY inhibits H+/K+ ATPase in stomach parietal cells.
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What are some side effects of omeprazole?
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Interferes with oxidation of warfarin, phenytoin, and diazepam.
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What is the mechanism of action of bismuth and sucralfate?
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Interacts with gastric mucosa to form a COMPLEX GEL creating a physical barrier that impairs HCL diffusion and pepsin-mediated degradation of mucosa.
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What is mechanism of bismuth and sucralfate?
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Bind to ulcer base, providing physical protection through COMPLEX GEL, and allow bicarbonate secretion to re-establish pH gradient.
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What is bismuth and sucralfate used for?
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Increase ulcer healing and traveler's diarrhea, and peptid ulcer disease.
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What is the triple therapy of H. pylori ulcers?
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metronidazole, bismuth/sucralfate, amoxicillin (or tetracycline).
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What drug requires an acidic pH for activation and not be given with H2 antagonists or antacids?
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sucralfate
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What is misoprostol?
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A PGE1 analog. It increases the production and secretion of gasric mucous barrier.
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What is misoprostol used for?
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Prevention of NSAID induced peptic ulcers
2) Maintenance of a patent ductus arteriosus 3) Induce labor |
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What is the toxicity of misopristol?
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1) Diarrhea
2) abortifactent in women of childbearing potential. 3) produce uterine contractions. |
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Where is the chemoreceptor trigger zone located?
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At caudal end of 4th ventricle (area postrema)
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What is pirenzipine and propantheline?
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muscarinic antagonists
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What is the action of pirenzipine?
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Block M1 receptors on ECL cells (decrease histamine secretion) AND M3 receptors on parietal cells (decrease H+ secretion)
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What is the toxicity of pirenzipine and propantheline?
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1) Bradycardia
2) dry mouth 3) difficulty focusing eyes. |
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What is infliximab?
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A monoclonal antibody to TNF-alpha, a pro-inflammatory cytokine.
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What are the uses for infliximab (a monoclonal antibody to TNF-alpha)
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Crohns disease, rheumatoid arthritis
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What is the toxicity of infliximab?
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Respiratory infection
Fever Hypotension |
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What is sulfasalazine?
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A combination of sulfapyridine (antibacterial) and mesalamine (anti-inflammatory): activated by colonic bacteria.
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What is sulfasalazine used for?
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Ulcerative colitis, Crohns disease
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What is the toxicity of sulfasalazine?
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malaise, nausea, sulfa allergy, reversible oligospermia!
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What is ondansetron?
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5HT-3 antagonist. Selective blocker of 5HT3 receptors in the CTZ.
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What is ondansetron used for?
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Control vomiting postoperatively and in patients undergoing chemotherapy.
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What is toxicity of ondansetron a 5HT-3 antagonist?
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Note: drugs used to treat migraines (sumatripan) are 5HT agonists, so use caution when treating migrane patients with ondansetron!
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What is a possible problem with antacid overuse?
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Can affect absorption, bioavailability, or urinary excretion of other drugs by altering gastric and urinary pH or by delaying gastric emptying.
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What is the mechanism of action of antacids?
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These agents (aluminum hydroxide, magnesium hydroxide, and calcium carbonate) are weak bases capable of neutralizng gastric acid.
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What are some side effects of alumnium hydroxide?
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Constipation and hypophosphatemia
1) ALUMINUM AMOUNT OF FECES |
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What are the side effects of magnesium hydroxide?
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Mg = Must Go to the bathroom
diarrhea! |
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What are the side effects of calcium carbonate?
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1) Hypercalcemia which can lead to rebound hyperacidity.
Remember: calcium salts can stimulate gastrin release. |
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What are antacids effect on other drugs?
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They can chelate and decrease absorption of certain drugs like tetracycline and levodopa.
All can cause hypokalemia! |
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What is the action of metoclopramide?
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Blocks dopamine and seretonin receptors in CTZ.
Used to treat emesis. |
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What is the side effect of metoclopramide?
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Diarrhea, extra-pyramidal symptoms (since its blocking DA and 5HT at CTZ).
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What is action of Mg OH2?
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Osmotic laxative (as well as antacid) that is non absorbable, so this substance attracts water into the intestinal lumen, thus distending the intestinal wall and increasing peristalsis.
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What is the action of cannabinoids?
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Used to treat emesis.
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What is the mechanism of action of loperamide?
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Activates opioid receptors that decrease peristalsis
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What is the mechanism of action of diphenoxylate?
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Activate opioid receptors that decrease peristalsis.
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Does loperamide cross the BBB?
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No, so it doesnt produce euphoria or respiratory depression characteristic of other opioids.
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what is the toxicity of diphenoxylate and loperamide?
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Toxic megacolon
They are antimotility agents. |
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What drugs can be used to treat diarrhea?
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1) Loperamide
2) Diphenoxylate They activate opioid receptors that decrease peristalsis. |
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What is the other class of drugs besides (diphenoxylate or loperamide) that can treat diarrhea?
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Adbsorbants
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What are the different types of adsorbants?
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Kaolin, pectin, methylcellulose
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What is the action of kaolin, pectin, and methylcellulose?
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Adsorption of intestinal toxins and increases stool viscosity.
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What is the mechanism of action of castor oil, senna, bisacodyl?
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irritates mucosal lining leading to hypermotility.
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What is the major side effect of castor oil, senna, phenolphthalein, and bisacodyl?
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Rebound intestinal hypomotility after discontinued
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What is the mechanism of action of stool softeners?
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Creates a hyperosmotic agent which draws water into the lumen of the intestines, and they lubricate the feces to ease transit.
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What are some examples of stool softeners?
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Mineral oil, glycerin, and docusate (NOT Castor OIL).
Castor oil is an irritant! |
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What are some examples of bulking agents?
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psyllium and methylcellulose
1) Draw water into intestinal lumen. |
