Drugs to treat PUD Flashcards
Stomach wall cells secrete ______ to produce protective layer coating the surface of cells.
They also recruit _______ to _______
Stomach wall cells secrete mucus to produce protective layer coating the surface of cells.
They also recruit bicarbonate to buffer acidity
Prostaglandins promote:
1.
2.
3.
- Mucus secretion
- Bicarbonate secretion
- Blood flow
Can taking NSAIDs increase risk of damage to stomach?
yes
Parietal cells release
H+
Histamine activation of h2 receptors activates ______ to release H+
proton pumps
Agents that reduce gastric acidity/ neutralise acids
- antacids
- H2 receptor antagonists
- PPIs
Antacids: they do NOT ___________, rather they ________
they do NOT prevent gastric acid production, rather they reduce gastric acidity
Rank most potent to least potent antacid
- Most: Sodium bicarbonate
Calcium carbonate
Mg OH
Al OH
Liquid antacid or tablet is btr?
Liquid. Due to rate of dissolution
Some antacid preps contain _______ as an anti-foaming agent (ease release of gas)
simethicone
Adverse effects of antacids:
- Na+
- Ca++
- Carbonates & bicarbonates:
- Mg++
- Al++
- Na+: increase in Na in bloos and thus fluid retention, hypertension, CHF
- Ca++: hypercalcemia, rebound acid secretion
- Carbonates & bicarbonates: will produce CO2 gases which can lead to belging & flatulence
- Mg++: osmotic diarrhoea
- Al++: constipation
MOA of H2-receptor antagonists
- competitive inhibitors of H2 receptors on parietal cells
- suppresses acid secretion by parietal cells
Efficacy of H2-receptor antagonists
Effective at:
Not effective at:
Effective at: inhibiting nocturnal acid secretion (due to histamine)
Not effective at: blocking secretion associated with meals
Rank most potent to least potent H2 receptor antagonist
Famotidine
Ranitidine
Cimetidine
Adverse effects of ___________
headache
nausea
dry mouth
rare: tachycardia blood dyscrasia blurred vision musculoskeletal pain
famotidine & ranitidine
Adverse effects of \_\_\_\_\_\_\_\_\_\_\_ headache nausea diarrhoea constipation fatigue mental confusion in critically ill pts men: gynaecomastia, impotence women: galactorrhea
cimetidine
Examples of PPIs
omeprazole
esomeprazole
PPIs inhibit ________ in _____ cells
PPIs inhibit H+K+-ATPase (proton pumps) in parietal cells
PPIs are reversible/irreversible
irreversible
PPIs are ______ pro-drugs, hence _____ bioavailability; can/cannot absorb well
PPIs are inactive pro-drugs, hence good bioavailability; can absorb well
PPIs are released and absorbed in _______
intestines
PPIs are given during :
usually 1h before bfast; on empty stomach
How many times of PPI is adminstered?
Once daily
Adverse effects of \_\_\_\_\_\_\_\_\_\_\_ headache nausea diarrhoea flatulence dizziness rash constipation long term: osteoporosis
other concerns (bot not proven): gastric cancer, pneumonia, Fe deficiency, vit. B12 deficiency
PPIs
Agents that protect gastric mucous
- sulcrafate
- bismuth compounds
- misoprostol
MOA of sucralfate
-vely charged sucrose sulphate binds postitively charged proteins at ulcer crater forming a viscous, tenacious gel that prevents further acid attack
stimulates mucosal prostaglandin & bicarbonate secretion
Sucralfate are given during :
usually 1h before bfast; on empty stomach
Adverse effects of sucralfate
constipation
impairs absorption of other drugs
Bismuth compounds stimulate ______ & ______ secretion.
They also has direct anti-microbial activity against ________.
stimulate mucus &. bicarbonate secretion
against H.pylori
Misoprostol is given how many times a day?
4 times daily
Misoprostol is to prevent _____-induced peptic ulcers
NSAID
- low dose:
- high dose:
- binds to PGE2 receptors
- low dose: increases mucus & bicarbonate secretion,, enhances mucosal blood flow
- high dose: decreases acid secretion
Adverse effects of \_\_\_\_\_\_\_\_\_\_\_ abdominal pain diarrhoea abortion (uterine contraction) bone pain & hyperostosis (excessive bone growth)
misoprotol
Triple-therapy for H pylori eradication
clarithromycin +
amoxicillin / metronidazole +
PPI
h pylori multiply best at pH
6-8 (alkaline)
Antibiotics typically administered ____ a day.
2x a day
Antibiotics are given during :
with or w/o food within 1 hr
Do you need to complete the course of antibiotic?
YES
Esomeprazole is better suited for pts with ____ than omeprazole.
NGT
PPIs lower ___________ of antibiotics against H pylori
minimum inhibitory concentration (MIC) (aka make antibiotics more effective)
PPI takes about _____ days to fully inhibit acid secretion
3-4 days
