Gastro - FA Pharm p392 - 394 Flashcards
name 4 H2 blockers
cimetidine, ranitidine, famotidine, nizatidine
what is the mech of H2 blockers?
reversible block of histamine H2 receptors –> dec proton secretion by parietal cells
among H2 blockers, what is unique about cimetidine?
inhibitor of P450 and also has antiandrogenic effects (prolactin release, gynecomastia, impotence, dec libido in males)
what 2 H2 blockers dec renal excretion of creatinine?
cimetidine, ranitidine
mech of proton pump inhibitor?
irreversible inhibition of H+/K+ ATPase
Side effects of PPI?
- inc risk of C. difficle infection 2. pneumonia 3.acute interstitial nephritis 4. dec serum Mg2+ with long term use 5. dec Ca2+ absorption
does PPI inhibit or induce P450?
inhibit (omeprazole)
name 3 antacids
- aluminum hydroxide 2. calcium carbonate 3. magnesium hydroxide
which antacid can chelate and dec the effectiveness of drugs such as tetracycline, fluoroquinolones
calcium carbonate
what is the common side effect of all antacid?
hypokalemia
mech of bismuth, sucralfate?
bind to ulcer base providing physical protection and allowing HCO3- secretion to reestablish pH gradient in the mucous layer
bismuth is also used is what other path?
H. pylori (Quadruple tx: PPI, bismuth, metronidazole, tetracycline)
which drug is a prodrug that requires acid to be activated?
sucralfate - needs acid, cannot be given w/ PPI or H2B
what is the drug that ripens cervix?
misoprostol (PGE1 analog)
What is misoprostol used for ?
Prevention of NSAID-induced peptic ulcers (NSAIDs block PGE1 production)
4 clinical applications for octreotide
- variceal bleeds 2. acromegaly 3. VIPoma 4. carcinoid tumors
Octreotide inc risk for ______ due to _______ __________
Inc risk of cholelithiasis due to CCK inhibition.
what is sulfasalazine?
combination of sulfapyridine (antibacterial) and 5-aminosalicylic acid (anti-inflammatory)
sulfasalazine need to be activated by
colonic bacteria
3 clinical usage for sulfasalazine?
- UC 2. Crohn (colitis component) 3. rheumatoid arthritis
`Why can sulfasalazine lead to fertility problems?
can lead to reversible oligospermia
MoA and use of loperamide
Agonist at μ-opioid receptors; slows gut motility.
Use - Diarrhea
what is the target of ondansetron?
5HT3 (-)’r in CTZ, dec CN X stimulation
side effects of ondansetron?
Headache, constipation, QT interval prolongation, serotonin syndrome.
2 mechanisms of ondansetron?
- dec vagal stimulation 2. powerful central acting antiemetic
side effects of metoclopramide?
inc parkinsonian effects, tardive dyskinesia, restlessness, drowsiness, diarrhea
2 conditions that are contraindicated to metoclopramide?
small bowel obstruction, parkinson dz
what is the clinical app for metoclopramide?
diabetic and postsurgery gastroparesis, antiemetic, persistent GERD
what is metoclopramide?
D2 receptor antagonist
metoclopramide can interact with what kinds of drugs?
Digoxin, diabetic agents
name of the drug that blocks gastric/pancreatic lipase
Orlistat
what is the clinical app of orlistat?
weight loss (dec breakdown and absorption of dietary fats)
side effects of orlistat?
Abdominal pain, flatulence, bowel urgency/frequent bowel movements, steatorrhea; dec absorption of fat-soluble vitamins.
name 4 osmotic laxatives
- magnesium hydroxide 2. magnesium citrate 3. polyethylene glycol (prep for colonoscopy) 4. lactulose
the mech of osmotic laxatives?
provide osmotic load to draw water into the GI lumen
Drug used for chemo induced n/v
Aprepitant, substance P antagonist (-) NK1 receptors in brain
Dronabinol - mech and use?
cannibinoid, dec n/v post chemo (last choice)
Mineral oil is used for? caution
as stool softener, (-) fat soluble vitamin absorption
Caution in elderly - risk of aspiration
SE risk for diphenoxylate
rebound constipation , mild sedation
What do u give to dec dependence to Diphenoxylate
Atropine - inc SE if overdose
