GORD / Peptic Ulcer Disease Flashcards
What is the action of NSAIDs (naproxen)?
target
location
effect
‘Target’ – COX 2 enzyme (naproxen is non-selective i.e. also inhibits COX1)
‘Location’ – Peripheral nociceptive nerve endings
(analgesia)
‘Effect’ – COX produces prostaglandins (PG). PGs do
not directly cause pain themselves, but they
sensitise peripheral nociceptors mediators (bradykinin and histamine) which causes pain. NSAIDs inhibit COX.
Explain one indirect effect on pain that NSAIDs have.
PGs mediate inflammation, and since NSAIDs inhibit COX, which produces PGs, NSAIDs will reduce inflammation
Explain how NSAIDs can have an adverse effect on the stomach.
target
location
effect
‘Target’ – COX I enzyme (unintended leading to side
effect)
‘Location’ – Gastric mucosal cells
‘Effect’ – Inhibition PG production and hence inhibition of PG mediated protection of gastric mucosa
What effect do PGs have on gastric mucosal cells?
protection from acid via:
- Increase Bicarbonate release
- Increase Mucus production
- Increase Blood flow
Which of the following can have systemic effects.
- oral NSAIDs
- topical NSAIDs
both
For which populations of people should doctors co-prescribe PPIs with NSAIDs?
those w/:
osteoarthritis and RA
elderly
low back pain, spondyloarthritis, psoriatic arthritis
For people w/ high risk GI adverse events, what should you prescribe w/ NSAIDs?
COX-2 selective NSAID + PPI
For people w/ moderate risk GI adverse events, what should you prescribe w/ NSAIDs?
COX-2 inhibitor alone
or
NSAID + PPI
For people w/ low risk GI adverse events, what should you prescribe w/ NSAIDs?
non-selective NSAID
How should you treat a patient with peptic ulcer disease but with no active bleeding and who is H. pylori neg.
For patients on NSAID, stop NSAID where possible.
- Offer full-dose PPI therapy for 4 to 8 weeks
- Several PPI options (ie. omeprazole: 20 mg orally OD
How does omeprazole work?
target
location
effect
‘Target’ – H +/K+-ATPase (‘proton pump’)
‘Location’ – Parietal cell (secretory membrane)
‘Effect’ – Reduced acid production from parietal cells.
NSAIDs leave stomach wall exposed to the
effect of acid, which is causing pain. PPIs
reduce the acid production.
How does omeprazole work?
target
location
effect
‘Target’ – H +/K+-ATPase (‘proton pump’)
‘Location’ – Parietal cell (secretory membrane)
‘Effect’ – Reduced acid production from parietal cells.
NSAIDs leave stomach wall exposed to the
effect of acid, which is causing pain. PPIs
reduce the acid production.
What does the Treatment algorithm say about patients taking 20mg omeprazole once a day.
What does the data say?
they should only be taking it for 4-8 weeks.
Data suggests that most patients prescribed PPIs are treated for at least 3 months (above the recommended treatment duration of 4-8 weeks) & are treated at twice the standard treatment dose i.e. 40mg versus 20mg.
Apart from peptic ulcer disease, what are some other adverse effects of NSAIDs?
cardiovascular and renal complications
(increased risk of thrombotic events)
What is the mechanism of action of histamine (H2) receptor antagonists in the treatment of peptic ulcer disease?
target
location
effect
Target – Histamine H2 receptor
Location – Cell surface of the parietal cell
Effect – decreased acid production from parietal cell.
Histamine receptors increase acid production via cAMP dependent activation of H +/K+ ATPase
The damaged mucosal barrier leaves stomach wall
exposed to acid -> symptoms pain.
decreased acid production, decreased corrosive nature of environment.
