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GI Pharm
GI Pharm
80
Medical
Professional
04/08/2011

Additional Medical Flashcards

 


 

Cards

Term
An increase in parasympathetic activity ___ the GI sphincters while ___ motility and tone
Definition
Relaxes the sphincters
Increases motility and tone
Term
The vagus releases ___, which stimulates ___ in the myenteric plexus. These neurons release ___, which stimulates ___, causing ___
Definition
ACh--stimulates pre-junctional M2R
5HT--stimulates 5HT2 and 3-R, causing contraction of GI smooth muscle and antegrade movement
Term
Sympathetic fibers release ___, which stimulates ___, located on ___. This causes ___, which ___.
Definition
NE--stimulates pre-junctional a2R located on parasympathetic fibers
Inhibits ACh release, which inhibits antegrade propulsion
Term
Stimulation of smooth muscle MuR causes ___, but ___, so ___ stops.
Definition
Tonic contraction
But decreased motility and secretion
Antegrade movement stops
Term
Stimulation of prejunctional parasympathetic fibers causes ___, which ___.
Definition
Partial inhibition of ACh release
Further suppression of antegrade movement
Term
Intrinsic nerves: effects of 5HT (3)
Definition
5HT2R: contracts GI smooth muscle
Pre-junctional 5HT4R: amplifies ACh release
Antegrade movement (along with ACh)
Term
Contraindications for emesis (4)
Definition
Petroleum stuff: can cause chemical pneumonia
Corrosives
CNS depressants
Stimulants: can ppt seizures
Term
Ipecac: MOA
Definition
Stimulates CTZ => local irritation of the stomach and upper duodenum
Term
Ipecac: S/E (7)
Definition
Diarrhea
Temporary drowsiness
Sedation
Lethargy
Fever
Diaphoresis

Chronic: emetine-induced cardiomyopathy
Term
Antiemetics (11)
Definition
Dexamethasone
Dimenhydrinate
Diphenhydramine
Dolasetron
Dronabinol
Hydroxyzine
Meclizine
Metoclopramide
Ondansetron
Promethazine
Scopolamine
Term
Scopalamine: MOA
Definition
M-R blocker in vestibular nuclei and reticular formation = antiACh
Term
Scopalamine: S/E (5)
Definition
Xerostomia
Sedation
Inability to concentrate
Amnesia
Fatigue
Term
Antihistamine/AntiACh antiemetics (5)
Definition
Dimenhydrinate
Diphenhydramine
Hydroxyzine
Meclizine
Promethazine
Term
5HT/DA-R blocker antiemetic
Definition
Metoclopramide
-5HT3R: vagal afferent fibers and CTZ
-D2R: CTZ
Term
5HT3-R blocker antiemetics (2)
Definition
Dolasetron
Ondansetron

5HT3R: vagal afferent fibers and/or CTZ
Term
Motion sickness prophylaxis (3)
Definition
Dimenhydrinate
Meclizine
Scopalamine
Term
Motion sickness treatment (1)
Definition
Promethazine
Term
Pregnancy n/v prophylaxis (3)
Definition
Dimenhydrinate
Meclizine
Ondansetron
Term
Flu n/v prophylaxis (1)
Definition
Promethazine
Term
Vestibular vertigo (Meniere's dz) n/v drugs (2)
Definition
Dimenhydrinate
Meclizine
Term
Prokinetic agent
Definition
Metoclopramide
Term
Metoclopramide: MOA
Definition
Stimulates pre-junctional 5HT4R on cholinergic fibers
Enhances ACh release
Term
Metoclopramide: effects (3)
Definition
Increased LES pressure
Gastric emptying
Antegrade movement of food through the GI tract
Term
Metoclopramide: indications (4)
Definition
Clear stomach prior to GI endoscopy/surgery
Tx infantile esophageal reflux
Diabetic gastroparesis
Tx post-op vomiting
Term
Bulk laxatives (3) and lactulose
Definition
Calcium polycarbophil
Methylcellulose
Psyllium
Lactulose

Don't cause laxative dependence
Term
Methylcellulose: composition, MOA
Definition
Indigestible bran, fruits, veggies

Attracts water => hydrogel with feces => increases bulk
Activates stretch receptors => increase peristalsis via local reflexes
Term
Methylcellulose: effects (4)
Definition
After 1-3 days
-Softens stool
-Increases volume and water content of feces
-Increases colonic transit rate
-Increases frequency of defecation
Term
Psyllium: composition, MOA
Definition
Indigestible seed coat => hydrophilic mucilloid

Attracts water => hydrogel with feces => increases bulk
Term
Calcium polycarbophil: composition, MOA
Definition
Hydrophilic resin

Draws water into bowel => increases bulk => activates local peristaltic reflexes
Term
Lactulose: composition, MOA, additional effect
Definition
Disaccharide

Not absorbed => bowel bacteria degrade it into acids => osmotic effect = draw water into the colon => increases bulk => increased peristalsis via local reflexes

Acidification of the colonic lumen traps blood ammonia as ammonium
Term
Stool softener (1)
Definition
Docusate

Doesn't cause laxative dependence
Term
Docusate: MOA
Definition
Anionic surfactant => lowers surface tension of feces => allows penetration of water => emulsification softens stool
Term
Irritant colonic agent (1)
Definition
Bisacodyl

Can cause laxative dependence
Term
Bicosadyl: MOA
Definition
Irritation => increased accumulation of water and electrolytes => enhances peristalsis via local reflexes
Term
Bicosadyl: effect
Definition
Soft, semifluid stool within 6-12 hrs p.o.
Purgative effect within 15-60 min per rectum
Term
Osmotic purgative agents (2)
Definition
Mg hydroxide
Polyethylene glycol

Can cause laxative dependence
Term
Osmotic purgatives: MOA, effect
Definition
Hypertonic => osmotic effect = draw water into the colon => increases peristalsis via local reflexes

Soft, semifluid stool within 6-12 hrs p.o.
Term
Tx constipation
Definition
Bulk laxatives (methylcellulose, polycarbophil, psyllium) + lactulose
Stool softener (docusate)
Term
Tx constipation indications (lots)
Definition
Post op ab/anal/rectal surgery
Hemorrhoids, hernia, anal lesions, rectal prolapse
CAD, HTN, prior MI/CVA
Term
Stool softeners are also added to ___ to prevent ___
Definition
Iron supplements
Prevent the constipating effect of iron
Term
GI exam drugs (3)
Definition
Bisacodyl
Mg hydroxide
Polyethylene glyco
Term
Cathartic drugs (2)
Definition
Bisacodyl
Mg hydroxide
Term
Tx IBD (5) and MOA
Definition
Corticosteroids
Mesalamine
Olsalazine
Bulk laxatives: expand large bowel => prevent alternating segmental contractions => restore antegrade peristalsis
M-R blocker (dicyclomine): prevent bowel spasm
Term
Antidiarrheals (5)
Definition
Bismuth subsalicylate
Diphenoxylate
Loperamide
Octreotide
Polycarbophil
Term
Opiates: drugs (2), MOA
Definition
Diphenoxylate
Loperamide

Direct and indirect inhibition of GI motility despite increased tone => stasis allows absorption and consolidation
Term
Polycarbophil: indications
Definition
Constipation: hydrates the feces
Diarrhea: consolidates
Term
Coating agent (1)
Definition
Bismuth subsalicylate
Term
Bismuth subsalicylate: S/E (3)
Definition
Bismuth not absorbed, but 90% of the salicylate is => salicylate toxicity
Decreased absorption of tetracyclines
Turns stools gray-black and radioopaque (but not melena!)
Term
Bismuth subsalicylate: antibacterial MOA, effect with other Ab
Definition
Binds to SH groups of microbial proteins => destroy tertiary structure

Reduce their adherent properties => prevent binding to epithelium

Synergism!
Term
Octreotide: MOA
Definition
Stimulates somatostatin-R in the GI tract
Term
Octreotide: indications (2)
Definition
Reduces diarrhea/flushing associated with carcinoid syndrome
Stop GI bleeding in patients with esophageal varices
Term
Tx bacterial diarrhea (1)
Definition
Ab
Bismuth subsalicylate

No diphenoxylate/loperamide
Term
Anti-ulcer drugs (10)
Definition
Al hydroxide
Cimetidine
Esomeprazole
Famotidine
Mg hydroxide
Misoprostol
Omeprazole
Ranitidine
Sucralfate
Ab triple tx: clarithro, amox, omeprazole
Term
H2R blockers (3)
Definition
Cimetidine
Famotidine
Ranitidine
Term
H2R blockers: physiologic effect
Definition
Gastric pH rises to 3-4 (recurrence is common after stopping tx)

No effect on LES pressure, gastric motility/emptying, pancreatic/biliary secretion
Term
Ulcer tx aims (4)
Definition
Eradicate H. pylori
Neutralize gastric acids
Decrease secretion of gastric acids: H2R blockers, PPI, PGE analogs (misoprostol)
Construct protective barrier (sucralfate)
Term
Antacids: MOA, S/E
Definition
Weak bases slowly soluble in water => pH rises to 3-4

Al compounds: constipation
Mg compounds: diarrhea
Toxicity in patients with renal insufficiency
Term
Cimetidine: S/E (3)
Definition
Inhibits P450
-Can't breakdown estrogen => anti-androgenic effects
-Increases the t1/2 of things like B-blockers, warfarin, diazepam

CNS effects: mental confusion to over psychosis in older patients/prior hx psych disease/large doses for long period
Term
PPIs (2)
Definition
Esomeprazole (S-isomer)
Omeprazole
Term
PPIs: MOA
Definition
Inhibit gastric H-K ATPase
Blocks acid secretion 24-72 hrs
Term
PPIs: physiologic effect
Definition
Inhibit basal, nocturnal, and stimulus-related acid secretion => pH rises to 4-5
Reactive increase in plasma gastrin concentration in some patients

No effect on LES pressure, gastric emptying/motility
No effect on release of IF from parietal cells (but increased pH partially inhibits absorption of protein-bound B12, but still no megaloblastic anemia)
No enterochromaffin hyperplasia/carcinoid tumors reported with long-term use
Term
Misoprostol: MOA
Definition
Stimulate PGE-R on gastric parietal cells => inhibit acid secretion (to simuli)
Protective effect on gastric mucosa

No effect on basal acid secretion
Term
Misoprostol: S/E (2)
Definition
Diarrhea
Don't give to women of child-bearing potential without adequate contraception b/c it's an abortifacient
Term
Coating agent
Definition
Sucralfate
Term
Sucralfate: MOA
Definition
Water-insoluble complex => polymerizes when pH <4 => sticky viscous gel that binds tightly to ulcerated gastric mucosa = protective layer

Poorly permeable to HCl, pepsin, trypsin, bile salts
Doesn't dissolve in the duodenum
Doesn't neutralize stomach acid or inhibit its secretion
Term
Sucralfate: efficacy
Definition
Duodenal > gastric ulcers
Prevents relapse
Healing rate not affected by smoking

Don't give with anything that increases pH!
Term
Sucralfate: S/E
Definition
Aluminum toxicity in patients with renal failure
Hypophosphatemia in chronic alcoholism
Term
Stress ulcer prophylaxis (3)
Definition
Antacids + H2 blockers: but predisposes to nosocomial pneumonia in ventilated patients due to the raised pH
Sucralfate: preferred for ventilated patients
Term
NSAID-induced gastropathy prophylaxis (2)
Definition
Misoprostol: use only in high-risk patients (>60 yo, smokers, prior hx), prevents GI ulcer/bleed, no effect on the pharm of NSAIDs
Sucralfate: decreases heartburn and epigastric pain
Term
Corticosteroid-induced gastropathy prophylaxis (1)
Definition
Misoprostol
Term
GERD drugs
Definition
PPIs
H2 blockers
Sucralfate
Antacids (symptomatic only)
Term
Mesalamine (5ASA): pharm
Definition
Capsule slowly releases 5ASA as it moves through the bowel
Term
Olsalazine: composition
Definition
2 5ASA molecules joined together
Cleaved by bacterial enzymes in the large bowel
Term
Gallstone dissolver
Definition
Ursodiol
Term
Ursodiol: properties (2)
Definition
Trace constituent of normal bile acid
Undergoes enterohepatic recirculation
Term
Ursodiol: MOA (4)
Definition
Increase ratio of bile acids and phospholipids
-Inhibit HMG CoA reductase => decrease cholesterol synthesis
-Reduce GI absorption of cholesterol
-Decrease biliary secretion of cholesterol

Promote formation of liquid crystalline phase at the surface of gallstones => increases solubility of cholesterol
Term
Tx primary biliary cirrhosis (1) and MOA
Definition
Ursodiol: slows progression to required hepatic transplant
Term
Tx hyperlipoproteinemia (1) and MOA
Definition
Psyllium: binds bile acids => depletes intrahepatic sterol pool => increased LDL-R, decreased LDL

Total decreased 5-15%
LDL decreased 10-20%
Term
Tx portal-systemic encephalopathy associated with chronic hepatic disease (1) and MOA
Definition
Lactulose: acidification of colonic lumen traps ammonia as ammonium => decreased plasma NH3 by 25-50%, improves mental state and EEG in 75%

Good for acute and chronic tx
Term
Other things to know about portal-systemic encephalopathy associated with chronic hepatic disease tx (3)
Definition
Lactulose as effective as neomycin, which decreases colonic ammonia by killing the bacteria
Co-tx with neomycin has additive effect

Don't use antacids since this opposes the acidification process
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