💊Pharmacology💊 - GORD Flashcards
What is diclofenac?
A very potent NSAID
What is the advantage of giving drugs topically (e.g. diclofenac as a gel)?
Attempts to confine drug effect to target area
Systemic effects to some extent are, however, inevitable
How do NSAIDs reduce pain?
Reduce prostaglandin synthesis
What is the mechanism by which NSAID’s reduce pain and inflammation?
Inhibit cyclooxygenase (mainly COX-2 but also COX-1) - decreased PG synthesis
Prostaglandins sensitize nociceptors → their reduction leads to decreased pain perception
Anti-inflammatory action → ↓ vasodilation, ↓ leukocyte infiltration, ↓ swelling → improved mobility
What adverse effects do NSAIDs have in the stomach?
COX-1 inhibition → ↓ protective gastric mucosal prostaglandins
Leads to reduced mucus and bicarbonate secretion, ↑ gastric acid secretion
Increased risk of gastritis, peptic ulcers, and GI bleeding → presenting as upper abdominal pain
How does decreased PG synthesis lead to a reduction in pain?
PGs do not directly cause pain themselves, but they sensitise peripheral nociceptors mediators (bradykinin and histamine) which causes pain
How can oral naproxen and topical diclofenac lead to adverse effects?
2 NSAIDs is a lot, especially when this potent
Topical drugs can still have systemic effects - hence combination with oral naproxen and the resulting abdominal symptoms
What can be co-prescribed with an NSAID to reduce risk of gastrointestinal pain?
Proton pump inhibitors (PPIs)
What should be given to a patient with a form of arthritis?
NSAID
Co-prescribe PPI
What should be given to someone who is elderly and in chronic pain?
NSAID and PPI
What should be prescribed to someone in chronic pain with a high risk of GI adverse effects?
COX-2 selective NSAID (e.g. etoricoxib, celecoxib)
PPI
What should be prescribed to someone in chronic pain with a moderate risk of GI adverse effects?
Specific COX-2 inhibitor
OR
NSAID + PPI
What should be prescribed to someone in chronic pain with a low risk of GI adverse effects?
Non-selective NSAID
What is the go-to treatment for peptic ulcer disease with no active bleeding and H. pylori negative?
For patients on NSAID, stop NSAID where possible.
Offer full-dose PPI therapy for 4 to 8 weeks
Several PPI options, one of which is omeprazole:20 mg orally once daily
What is the mechanism of action of PPIs?
Target: H⁺/K⁺-ATPase (proton pump) in gastric parietal cells.
Action: Irreversible inhibition → prevents final step of gastric acid secretion.
Effect: ↓ HCl production → increased gastric pH → ulcer healing & symptom relief.
