GORD Flashcards
What drugs can be given to treat GORD?
- PPIs
- Histamine receptor antagonists
How do NSAIDs work to alleviate pain?
- They inhibit the enzyme cyclo-oxygenase (COX) which is the rate-limiting step for the production of all prostanoids (prostaglandins & thromboxanes).
- This reduces the amount of Prostoglandins and thus alleviates pain.
How do prostaglandins work to induce pain?
- They sensitise peripheral nociceptive C fibres which lowers their threshold for electrical stimulation. This makes it easier to stimulate them and cause pain.
- They sensitise peripheral nociceptor mediators like bradykinin and histamine which causes pain.
Which prostaglandin is mainly involved in causing pain in inflamed tissues (e.g in arthritis)?
Prostaglandin E2
There are 2 forms of the COX enzyme. Inhibition of which one has an analgesic effect?
COX-2
Why are one of the main side effects of NSAIDs peptic ulcers/ gastric irritation?
Inhibition of COX-1, the other major form of COX.
Where is the COX-1 enzyme (which when inhibited leads to gastric injury) found?
Gastric mucosal cells
How does NSAID inhibition of COX-1 cause peptic ulcer disease?
- NSAID inhibits prostaglandin synthesis.
- In the stomach, prostaglandins are involved in protecting the gastric mucosa from acid. If reduced, the mucosa will be more vulnerable and inflammation-prone.
How do prostaglandins protect mucosal cells from acid?
- increase bicarbonate release
- increase mucus production
- increase blood flow
Why is bad blood flow especially relevant in ulcer formation?
Tissue repair is dependent on good blood supply. Reduced blood flow means less tissue repair of ulcers in the stomach.
Except for gastric injury, what are other adverse side effects of NSAIDs?
- Reduced creatinine clearance and possible nephritis
- Prolonged use -> chronic renal failure
- Skin rashes & other allergies - - Dizziness
- Tinnitus.
- Adverse cardiovascular effects in those at risk (hypertension, stroke, MI)
In young children, what has using Aspirin (an NSAID) been linked with?
A rare but serious post-viral encephalitis (Reye’s syndrome)
Name some NSAIDs.
- naproxen
- diclofenac
- ibuprofen
(-aspirin)
What are the main uses of NSAIDs?
- analgesics (for the relief of mild to moderate pain)
- anti-pyretics
- anti-inflammatory drugs for chronic control of inflammatory diseases
How do PPIs work (Target, Location, Effect) ?
Irreversible inhibitors of H+/K+ ATPase on the apical membrane of gastric parietal cells which reduces the amount of gastric acid produced by parietal cells.