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60 Cards in this Set
- Front
- Back
classes of drugs to prevent and treat vomiting?
|
anticholinergic
antidopaminergic 5-HT3 antagonists H1 antihistamines cannabinoids corticosteroids benzodiazepines |
|
stimuli that trigger vomiting?
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stimulation of sensory nerve endings in gi tract and pharynx;
endogenous emetic substances produces as result of radiation damage or disease; disturbance of vestibular apparatus; stimuli to the sensory nerves of the heart and viscera; endocrine factors; rise in intracranial pressure; nauseating smells; repulsive sights; disgusting experience |
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chemoreceptor trigger zone?
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area postrema on floor of IV ventricle;
sensitive to chemical stimuli due to poorly developed bbb |
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vomiting center?
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dorsolateral border of reticular formation of medulla;
consists of N. tractus solitarius, parvicellular reticular formation, and visceral and somatic motor nuclei coordinating the act of vomiting; integrates the emetic response |
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where does VC receive excitatory inputs from?
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vagal sensory from gi
labyrinths via vestibular nuclei higher cortex centers CTZ intracranial pressure receptors |
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drugs that can cause emesis via action on CTZ?
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apomorphine
L-dopa cardiac glycosides emetine estrogens ergot alkaloids opiates cancer chemotherapeutic agents |
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mechanism of drugs causing emesis by acting locally on gi?
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activate enterochromaffin cells in mucosa --> release of 5-HT --> stimulation of 5-HT3 receptors --> excite N. tractus solitarius --> activates VC;
aka 'local irritants' |
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drugs causing emesis via action locally in gi?
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ipecac
copper sulfate zinc salts antimony salts |
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when might drugs causing emesis be useful?
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ingesting harmful substance;
patient must be conscious; must be within certain time so substance has not passed the stomach |
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most highly emetogenic agent?
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cisplatin
|
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hyoscine?
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M antagonist
prevention of motion sickness ineffective against substances acting in CTZ |
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H1 antihistamines?
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cinnarizine
cyclizine promethazine |
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use of antihistamines?
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motion sickness
ineffective against substances acting in CTZ |
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why are newer antihistamines not useful in prevention of emesis?
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do not cross the bbb
|
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antidopaminergics?
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metoclopramide
domperidone |
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metoclopramide?
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D2 blocker at CTZ
psychotic side effects |
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domperidone?
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D2 blocker at CTZ
does not cross bbb so no cns side effects preferred vs metoclopramide |
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benzodiazepines use as antiemetics?
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anticipatory n/v before cancer therapy
useful for vestibular disorders |
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PONV?
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post operative nausea and vomiting
|
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corticosteroids use as antiemetics?
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prevention of PONV
reportedly as effective as ondansetron |
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nabilone?
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synthetic cannabinoid derivative
not well accepted |
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5-HT3 antagonists?
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ondansetron
granisetron |
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5-HT3 antagonist use?
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prevention of n/v due to cancer chemotherapy and causes little toxicity;
given in combo with dexamethasone (synergistic); widely used for PONV but less effective; sublingual preps available |
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complications of peptic disease?
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hemorrhage
obstruction perforation |
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factors that influence peptic ulcer disease?
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lifestyle
smoking alcohol stress |
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how does smoking affect peptic ulcer disease?
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slows healing of existing ulcers
increased chances of getting an ulcer |
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how does caffeine affect ulcers?
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stimulate acid secretion in stomach, aggravating pain of existing ulcer
|
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how does stress affect ulcers?
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emotional stress increases pain
physical stress increases risk of developing ulcers |
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ulcer presentation?
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gnawing or burning pain in epigastrium
n/v loss of appetite bleeding anemia (due to prolonged bleeding) |
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gold standard treatment for peptic ulcer disease?
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H2 blockers
|
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H2 blockers characteristics?
|
competitive antagonist to block acid release;
promote healing; useful for hypersecretory states (zollinger-ellison); prophylaxis for at risk patients; useful for reflux esophagitis, bile reflux gastritis, prevention of aspiration pneumonitis |
|
cimetidine?
|
H2 blocker
reduces acid secretion by 70% for 4-5 hrs so patient compliance can be problematic as taking high dose often |
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side effects of cimetidine?
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gi upset
headache confusion gynecomastia (androgen receptor antagonist) increased prolactin release impotence inhibitor of microsomal enzymes decreased bioavailability with antacids |
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ranitidine?
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H2 blocker
more potent than cimetidine none of side effects of cimetidine does not bind to testosterone receptors low incidence of headache and rash |
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H2 blockers?
|
cimetidine
ranitidine nizatidine famotidine roxatidine |
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effect of anticholinergics?
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decreased ACh stimulated secretion and motility;
rare systemic anticholinergic effects; rarely used alone |
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antacids characteristics?
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weak bases to partially neutralize gastric acid, reduce pain associated with ulcers, and promote healing;
danger of over-neutralizing resulting in alkalosis |
|
calcium carbonate?
|
antacid
overuse can lead to hypercalcemia contraindicated with renal disease rebound acid production due to stimulated gastrin release |
|
magnesium hydroxide?
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antacid
can cause diarrhea and lead to hypotension |
|
aluminum hydroxide?
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antacid
can cause constipation binds bile acids stimulates mucus secretion |
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which antacid stimulates mucus secretion?
|
aluminum hydroxide
|
|
sodium bicarbonate?
|
antacid
not for long term therapy contraindicated with HTN due to Na content |
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drug interactions with antacids?
|
altered bioavailability of drugs due to change in pH;
chelation of drugs to prevent absorption (digoxin and tetracyclines) |
|
omeprazole?
|
proton pump inhibitor
inhibits parietal cell proton pump by covalent modification |
|
side effect of omeprazole?
|
hypertrophy of gastrin producing cells;
inhibits microsomal enzymes; tumors in animals at high doses |
|
proton pump inhibitors?
|
omeprazole
urogastrone enterogastrone |
|
sulcralfate?
|
protective agent;
complex polysaccharide complexed with aluminum hydroxide; crosslinks in gastric pH with affinity for exposed proteins in peptic ulcers |
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sulcralfate side effect?
|
nausea
constipation |
|
requires acidic gastric pH to be activated?
|
sulcralfate
|
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complications of untreated GERD?
|
severe chest pain
esophageal stricture bleeding barrett's esophagus |
|
important features of h. pylori?
|
potent producer of urease
2/3 world infected unknown transmission unknown reason for symptomatic presentations most never suffer symptoms associate with gastric cancer |
|
confirmation of h. pylori presence?
|
IgG
breath test upper esophgogastroduodenal endoscopy |
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agents that increase fecal bulk?
|
psyllium
carboxymethylcellulose dietary fiber polycarbophil calcium polycarbophil |
|
salt containing osmotic agents?
|
magnesium sulfate
magnesium citrate magnesium hydroxide sodium phosphates mineral waters |
|
use of salt containing osmotic agents?
|
bowel evacuation prior to surgery
elimination of parasites after therapy |
|
non salt containing osmotic agents?
|
glycerine
lactulose polyethylene glycol irritant agents wetting agents coating agents |
|
antidiarrheals?
|
adsorbents
glucocorticoids bismuth subsalicylate loperamide anticholinergics |
|
adsorbents?
|
kaolin
pectin (donnagel) dietary fiber |
|
use of opioid preparations?
|
high doses to control refractory diarrhea
|
|
opioid preparations?
|
opium tincture
camphorated opium tincture codeine diphenoxylate |