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57 Cards in this Set
- Front
- Back
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antacids
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CaCO3 - absorbed
NaHCO3 - absorbed Mg(OH) - not absorbed Al(OH) - not absorbed |
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H2 antagonists
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Ranitidine
Cimetidine Famotidine Nizatidine |
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PPI
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Omeprazole
Esomeprazole Lansoprazole Dexlansoprazole Pantoprazole Rabebrazole |
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Physiology of acid secretion
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1. Neural stimulation via vagus
2. Endocrine stimulation via gastrin 3. Paracrine stimulation by histamine release from enterochromaffin-like (ECL) cells | V Acid production by proton pumps on the apical membrane of parietal cells |
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Antacid clinical use
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Occasional GERD or dyspepsia
Can be used to determine if CP is acid reflux Replaced by H2B and PPI for ulcers |
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Antacid adverse reactions
NaHCO3 Mg(OH)2 Al(OH)3 CaCO3 |
Na - FLUID RETENTION, syst. alkalosis (esp renal insuf)
Mg - DIARRHEA, hyperMg (if renal insuf) Al - CONSTIP., hypoPhos, drug adsorption (bioavail) Ca - hyperCa, kidney stones, acid rebound, constip? |
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H2R Antagonists
Characteristics |
Competitively inhibit H2 (GPCR)
-> decreased cAMP->decreased pump activity Also decrease pepsin secretion Tachyphylaxis Short term (hours) -PRN for GERD, w/PPI for PM-breakthrough sx -SUP in high risk, PPI better for ZES Low toxicity |
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Cimetidine adverse effects
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inhibit cytochrome P450
Antiandrogenic (gynecomastia, galactorrhea) Cardiovascular problems Confusion in elderly ---thus less commonly used than other H2B |
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PPI background
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Inhibit H/K ATPase in apical membrane of parietal cells
All require conversation to sulfonamide intermediate which forms irreversible complex with ATPase Native drugs destroyed by GI acid. Special coating 30 minutes before mean. Effects last up to 24-48 hr |
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PPI adverse effects
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Generally well tolerated
Most common: HA, And pain, N, D, Farts Metabolized by P450 Increased risk for GI infections, bone fractures, aspiration pneumonia, hypomagnesemia |
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Clinical use of PPI
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PUD
GERD Reflux esophagitis ZES - IV for UGIB -reduce need for endoscopic intervention -decrease risk for recurrent UGIB s/p intervention |
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Mucosal protectants
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Bismuth salts
Sucralfate Misoprostol |
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Bismuth salts
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Coats ulcers and inflamed areas
multiple mechanisms poorly understood caution: black tongue and feces interaction with anticoagulants Gastroenteritis - helps sx of N/D/dyspepsia Traveler's D ppx (tho, others used) |
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Sucralfate
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Forms gel-like material on ulcers
Protects from acid and digestive enzymes Take before meals (ante sebum) SUP (replaced by PPI) Bile-reflux gastritis Esophageal ulcers (e.g. post variceal banding ulcers) |
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Misoprostol
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PG E1 analog
stimulates mucopolysaccharide production decreases acid secretion induces labor Combined with NSAIDs to reduce ulcer risk |
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Drugs effecting GI motility
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ABX = Erythromycin
Cholinomimetic = Bethanechol, neostigmine DA rec. antagonist = metoclopramide, domperidone Serotonin (5HT) = metoclopramide @ high dose |
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Macrolide ABX
(erythromycin) |
Prokinetic:
Activate motilin receptors on smooth muscle of the antrum and small intestine Use sparingly: tachyphylaxis and QT prolongation |
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Cholinomimetics
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Prokinetic: activate ACh receptors
Potently increase GI motility Multiple cholinergic and cardiac side-effects limit use IV neostigmine shown highly effective in acute colonic pseudo-obstruction (Ogilvie's syndrome) |
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DA receptor antagonists
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Metoclopramide
Domperidone Act pre & post-synaptic DA receptor antagonism promotes gastric/intestinal motility through release of Ach -increased gastric tone/pressure -improved antroduodenal coordination -accelerated gastric emptying |
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Metoclopramide (Reglan)
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Common side effects:
somnolence, feeling jittery, HD, insomnia, diarrhea Also serious nervous system disorders -tardive dyskinesia: involuntary, repetitive movements (may be irreversible) -dystonia -neuroleptic malignant syndrome Confirm dx before using, detailed discussion with pt and written consent |
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Laxatives:
Bulk forming Osmotic agents Stimulants Stool softeners Chloride channel secretion |
Bulk forming: psyllium, CMC, polycarbophil
Osmotic agents: lactulose, Mg salts, NaPO4, PEG Stimulants: Bisacodyl, seena, cascara, castor oil Stool softeners: Docusate, glycerin, mineral oil Cl channel secretion: Lubiprostone |
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Fiber lax
(bulk forming) |
Bulk forming: psyllium, carboxymethylcellulose (CMC), polycarbophil
Form gels in colon causing water retention and distention that leads to increased peristalsis |
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Osmotic lax
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Osmotic agents: lactulose, Mg salts, NaPO4, PEG
Draw H2O into lumen by osmosis Softer/liquid stool and distention induced peristalsis |
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Stimulant/irritant lax
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Stimulants: Bisacodyl, seena, cascara, castor oil
stimulates colonic smooth muscle and cause water accumulation in lumen; exact mechanism unclear |
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Stool softener lax
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Docusate - causes H2O and fat to mix
glycerin - enhances H20 retention mineral oil - softens stool, prevents H2O absorption, can inhibit fat soluble vitamin absorption |
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Anti-diarrhea agents
1. Anti-motility 2. Adsorbants 3. Antisecretory |
1. Anti-motility - loperamide, diphenoxylate/atropine, tincture of opium
2. Adsorbants - bismuth subsalicylate, fiber, cholestyramine, colestipol 3. Anti-secretory - octreotide, somatostatin |
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anti-motility
(opiates) |
Opioid receptor
loparamide, diphenoxylate/atropine, tincture of opium act directed on circular and long. muscle -inhibit peristalsis and prolong transit time -increase viscosity -diminishes fluid and electrolyte loss Increases anal sphincter tone |
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adsorbents
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Bismuth subsalicylate
-anti-secretory -antimicrobial -anti-inflammatory Fiber -bulking agents - "stool regulator" improves consistency Cholestyramine, colestipol -bile acid binding resin -prevent unabsorbed bile acids from irritating colonic mucosa and causing more electrolyte and fluid secretion |
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anti-secretory
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Octreotide/somatostatin
-reduces fluid and electrolyte secretion by stomach and pancreases -mild anti-motility effect -promotes intestinal electrolyte absorption -suppresses neuroendocrine tumor release of peptides that cause intestinal hyper secretion of electrolytes and water |
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Anti-diarrheas
warnings and precautions |
Do not give in setting of acute bacterial infection or inflammation
-->could get toxic megacolon |
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Anti-diarrheas
warnings and precautions |
Caution when combining loperamide and tincture of opium with other CNS depressants
-->sedation, respiratory depression |
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Anti-diarrheas
warnings and precautions |
Remember the "salicylate" in bismuth subsalicylate
-caution for pt on ASA or anti-coagulation -Reye syndrome |
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Anti-diarrheas
warnings and precautions |
Separate cholestyramine from other medications by at least 2 hours (bind, reduce bioavailability)
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Nausea and Emesis
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anticholinergic: scopolamine
Antihistamine: meclizine, dimenhydrinate DA-antagonist: prochlorperazine, promethazine 5-HT3-antagonist: ondansetron, dolasetron, granisetron Cannabinoid: dronabinol Neurokinin antagonist: aprepitant |
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Antiemetics: anticholinergic
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Block ACh at M1
Scopolamine prevents motion sickness But less effective at treating it Can prevent chemo-induced nausea Transderm patch 72 hr Antichoinergic side effects: dry mouth, sedation, blurred vision; and confusion and urinary retention in the elderly |
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Antiemetic: antihistamine
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Antihistaminic (H1) and anticholinergic
Mechlizine, dimenhydrinate Effect in tx of motion sickness Tablet, oral suspension, IM dimenhydrinate Antichoinergic side effects Meclizine may be less sedating than dimenhydrinate |
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Antiemetics: DA-antagonist
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D2-receptor blockers, some anticholinergic effects
Promethazine, proclorperazine Effective antiemetic in mutliple settings Oral tablet or suspension, rectal, IM, IV ADE: sedation, QT prolongation, anticholinergic; extrapyramidal sx = pseudoparkinsonism, acute dystonic reactions and tardive dyskinesia |
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Antiemetics: 5-HT3 antagonist
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Selective 5-HT3 receptor antagonist, vagal nerve terminals and chemoreceptor trigger zone
Ondansetron, dolasetrong, granisetron Effect for multiple settings including -chemo-induced N/V Adverse effects: QT prolongation |
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Antiemetics: cannabinoid
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CNS cannabinoid (CB1) receptor agonist, likely interacts with multiple neurotransmitters
Delta-9-tetrahydrocannabinol (THC) - "Marinol" PO Approved for chemo-induced N/V and appetite stimulant for HIV/AIDS Adverse effects: euphoria, paranoia, CNS depression and abuse potential |
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Antiemetics: NK antagonist
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Substance P/neurokinin-1 receptor antagonist
Aprepitant, fosaprepitant Effective in prevention of acute and delayed chemotherapy-induced and postoperative N?V, especially as adjunctive to therapy PO, IV (fos) before chemo or anesthesia ADE: hiccups, fatigue, increased risk for severe infection |
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Selection of anti emetics by clinical situation:
migraine-related nausea |
DA-antagonist
5-HT3 antagonist |
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Selection of anti emetics by clinical situation:
Motion sickness |
anticholinergic
antihistamine |
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Selection of anti emetics by clinical situation:
Chemo-induced N/V |
5-HT3-antagonist
corticosteroids NK antagonists others: cannabinoids, benzodiazepines |
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Post-op N/V
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DA-antagonist
5-HT3 antagonist NK-antagonist |
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Hyperemesis gravidarum
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Ginger
B6 Antihistamine DA antagonist 5-HT3 antagonist |
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Anti-inflammatory:
aminosalicylates |
topical anti-inflammatory effect via multiple mech.
sulfasalazone: prodrug in the colon ---bacterial azoreductase --> 5ASA 5-aminosalicylate: mesalamine, balzalazide, olsalazine ->75% absorbed in jéjunum Effectin in UC and Crohn's of colon |
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aminosalicylate: warnings/precautions
sulfasalazine |
sulfasalazine:
freq GI, CNS and hematologic effects agranulocytosis is rare (serious) decrease folic acid absorption (supp. 1mg/daily) |
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aminosalicylate: warnings/precautions
5-ASA |
5-ASA
mild GI side effects hypersensitivity rxn: pancreatitis, pneumonitis pradoxical worsening of disease chronic interstitial nephritis |
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Glucocorticoids
conventional |
Predisone, methylprednisone
effective induce remission UC/CD -generally reserved for mild/mod disease Should be used for short term induction, not maintenance therapy cannot stop w/o tapering (adrenal insufficiency) |
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Glucocorticoids
non-systemic |
Budesonide
controlled ileal release vs. extended colonic release high first pass hepatitic metabolism induction agent in CD, not effective for long-term maintenance lower incidence of adrenal suppression, but still requires a taper |
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Immunomodulators: 6-MP/AZA
pathway |
AZA --> 6-MP
6-MP --(TMPT enzyme)-> 6-MMP (inactive) and 6-MP-->>>6-TGN (active, inhibited nucleotide synth) |
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Immunomodulators: 6-MP/AZA
use and ADE |
Maintenance of remission in CD and UC
Tx levels reached at 3 months Adverse effects: leukopenia, thrombocytopenia (6TGN) hepatotoxicity infection increased risk of malignancy avoid use with allopurinol which shunts towards active metabolite |
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Immunomodulators: methotrexate
mechanism |
folate antimetabolite
competitively inhibits DHF to DHFR Thought to induce apoptosis in T cells |
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Immunomodulators: methotrexate
use and ADE |
maintenance for CD
ADE: hepatotoxicity myelosuppression interstitial lung disease (rare, significant) give folic acid 1mg daily to all patients to prevent megaloblastic anemia teratogenic, contraindicated in pregnancy |
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Biologics: anti-TNFa
use, ADE |
induction and maintenance of CD and UC
ADE reactivation risk (TB, HBV) Myelosuppression Increased risk of malignancy Psoriasis, drug-induced lupus, demyelination |
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Biologics: anti-TNFa flavors
Infliximab Adalimumab Certolizumab Golimumab |
IFX: Chimeric (Both)
ADA: Humanized (Both) CTZ: PEG-Fab (CD) GOL: Humanized (UC) |
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Biologics: anti-integrins
Natalizumab |
Blocks leukocyte migration from blood vessels to sites of inflammation
increased risk of progressive multifocal leukoencephalopathy (PML) - exposed to JC virus New (Vedolizumab) may be GI specific |
