Drug Classes that Influence Acid Secretion Flashcards
What is omeprazole an example of?
A PPI
How do PPIs block?
covalent modification
What do NSAID block and is it reversible or irreversible?
cyclo-oxygenase, irreversibly
Do H2 receptor antagonist block competitively or non competitively?
competitively
What is pirenzepine an example of?
Muscarinic receptor antagonist
What do muscarinic receptor antagonists involved in influencing acid secretion block?
ACh competitively on M1 and M3
What do NSAIDs do to prostaglandin formation?
reduce it
How can gastric damage due to a long term NSAID treatmend be prevented?
with a stable PGE1 analogue e.g. misoprostol
How does drug treatment of peptic ulcers aim to promote ulcer healing?
reducing acid secretion, increasing mucosal resistance and eradicating H.Pylori
What is an example of a condition with acid hypersecretion?
Zollinger-Ellison Syndrom or CUshing’s ulcers
What is Zollinger Ellison Syndrome?
rare gastrin producing tumour
What is Cushing’s ulcers?
heightened vagal tone
What do PPIs inhibit?
active H+/K+ dependent ATPase proton pump
Are pumps in tubulovesicles inhibited?
No
Are PPIs prodrugs?
yes
When are PPIs active?
inactive at neutral pH, become active in strongly acidic environment e.g. caniculus
Do PPIs inhibit all available pumps?
Yes
Does inhibition of acid secretion exceed plasma hald life?
Yes greatly (except in tentroprazole)
How are PPIs administered?
orally once a day
What problem might occur at night with PPIs?
nocturnal acid breakthrough
Is the full effect of a PPI achieved without repeated dosing?
No
How are H2 receptor antagonists administered?
orally once or twice a day
What is pirenzipine an example of?
A muscarinic ACh receptor antagonist
Are muscarinic Ach receptor antagonists used nowadays?
No
Are gastrin receptor antagonists eg prolgomide used clinically?
No
What do mucosal strengtheners require?
acidic environments
How do mucosal strengtheners work?
bind to ulcer base and form complex gel with mucus
What is bismuth chelate toxic to?
H. Pylori
What does the antacid Mg triscilicate form?
MgCl2 and colloidal silical (which binds pepsin)
What do magnesium salts cause?
diarrhoea
What is the combination therapy used to treat a peptic ulcer?
omeprazole + clarithromycin + either amoxycillin OR metronidazole
What type of drugs are domperidone and metroclopramide?
Pro motility drugs
