Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
41 Cards in this Set
- Front
- Back
|
2 physiological agents that induce secretion of acid
|
gastrin, histamine
|
|
|
makin pathway that regulate acid production?
|
meal/anticipation of meal --> releases gastrin from gastrin containing cells --> induces release of histamine from enterochromaffin like cells (ECL) --> histamine diffuses to parietal cell and acts on H2 receptors on parietal cells to produce cAMP and activate proton pump -> secrete H+
|
|
|
minor pathway that regulates acid production
|
activation of M1 receptors on ECL cells cause histamine release; activation of M3 receptors on parietal cells cause Ca+ mediated acid release; activation of gastrin receptors on parietal cells cause Ca+ med acid release; activation of EP receptors on parietal cells activated by prostaglandin inhibit acid secretion
|
|
|
what does proton pump do
|
membrane bound H+ K+ ATPase protein that pumps H+ into lumen across conc gradient
|
|
|
for disease causally linked to Helicobacter pylori, what is the main risk factor?
|
infected family membors; gastric/ duodenal uclcer
|
|
|
in gastric/duodenal ulcers, what is secreted by causative agent that neutralizes gastric acid
|
h. pylori secretes urease
|
|
|
what is the therapy for gastric/duodenal ulcers?
|
antibacterial plus agent that decreases acid
|
|
|
5 ways to diagnostically test for h. pylori
|
serology; non-endoscopic urease test (urease breath test, measure expired CO2); fecal antigen test, culture, endoscopy
|
|
|
first line for GERD, major dyspepsia, acid disorders?
|
proton pump inhibitors
|
|
|
MOA of PPIs?
|
suicide inhibitor of HKATPase - covalent binds, prodrug activates in acidic environment and becomes protonated and trapped on acidic parietal cell
|
|
|
admin and form of PPI?
|
delayed release, gelatin coated capsules, or enteric coated granules or tablets, or powdered drug with sodium bicarbonate; absorbed rapidly, better absorb before meal
|
|
|
half life and absorption of PPI?
|
absorb rapidly, bound to plasma portein, cleared by hepatic metabolism, metabolites excreted in urine.
t1/2 of 30-90 min |
|
|
which PPI is least metabolized by CYP2D19
|
rabeprazole
|
|
|
for peptic ulcers, which is better: H2 antagonists or omeprazole
|
omeprazole
|
|
|
what other syndrome is PPI used for?
|
zollinger-ellison
|
|
|
what should you worry about for long term, high dose PPI therapy in elderly?
|
increased incidence of hip fracture
|
|
|
first line therapy for eradicating H pylori infxn
|
PPI + amoxicillin + clarithromycin
|
|
|
if you have a resistant H pylori infxn what can you give them
|
PPI + bismuth subsalicylate + tetracycline + metronidazole
|
|
|
what is the mechanism of action for the non-ulcer dyspepsia tx that has an anti-androgenic side effect?
|
h2 receptor antagonist (cimetidine); acts via histamine H2 receptors on parietal cells; inhibits acid secretion stim by gastrin and muscarinic agonists; inhbits gastric HCl secretion
|
|
|
what does H2 receptor antagonists decrease and block?
|
volume of gastric juice, pepsin production, intrinsic factor production
|
|
|
what is a potential complication of h2 receptor antagonists?
|
vit deficiency
|
|
|
3 mucosal protective agents
|
colloidal bismuth compound, misoprostol (cytotec), sucralfate (carafate)
|
|
|
what should you never use in pregnant women bc its side effect of uterine contraction?
|
misoprosol, a mucosal protective agent
|
|
|
how does subsalicylate work?
|
increases mucosal secretion, coats ulcer, detachment of h pylori from gastric epithelium and bacteria lysis; no acid-neutralizing activity
|
|
|
what is the MOA of a rapidly absorbed mucosal prot agent that is approved only for NSAID induced gastric ulcers?
|
synthetic analog of PGE1, decrease gastric acid secretion, increases mucus and bicarb secretion
|
|
|
what is triple therapy?
|
multi drug therapy
|
|
|
what mechanism is responsible for lengthy duration of action in ppis
|
covalent binding to HKATPase, new synth of enzyme must be made
|
|
|
which h2 antagonist may be admin IV?
|
?
|
|
|
how does sucralfate and misoprostol differ in moa?
|
sucralfate- complex Al-sucrose sulfate; thought to coat ulcer, acid/pepsin barrier, may stim pge synth
misoprostol - synth analog of pge, increases mucus, bicarb, decreases acid secretion |
|
|
list major antacids?
|
sodium bicarb, calcium carbonate, magnesium salts, aluminum compounds, antacid mixtures
|
|
|
role of colloidal bismuth compound in triple therapy?
|
used with PPI and tetaracycline and metronidazole for resistant h pylori
|
|
|
what are the side effects/toxicity of a drug in which bases present react to neutralize stomach acid, decrease heartburn/pain sx, heal ulcer?
|
alkaluria and kidney stones, high sodium content dangerous for hypertensive or CHF pts
|
|
|
what exacerbates GERD and is not recommended for peptic ulcer tx, GERD, hypertensives, most others?
|
sodium bicarbonate
|
|
|
which antacid is recommended for women, esp pregnant women?
|
calcium carbonate, tums
|
|
|
what antacid that produces belching also causes transient metabolic alkalosis
|
sodium bicarbonate
|
|
|
which antacids are cathartics, osmotic effects, and stim intestinal motility?
|
magnesium salts, milk of magnesia
|
|
|
what is one diff between sodium bicarb and magnesium salts
|
mg salts have longer duration of action
|
|
|
which constipating antacid binds to phosphate preventing absorption and shouldn't be given with tetracycline?
|
aluminum compounds
|
|
|
what happens to aluminum compounds on storage
|
lose potency
|
|
|
which two antacids are usually used together to overcome constipating and cathartic side effects?
|
aluminum and magnesium
|
|
|
what are all the uses of ppis?
|
gerd, peptic ulcer, major dyspepsia, nsaid induced ulcer, lifetime therapy, zollinger ellison syndrome
|
