2. Hyperuricaemia and gout Flashcards
Gout
What is it?
Uric acid crystals commonly form on joints, usually the big toe
Gout symptoms
- Sudden, intense joint pain swelling
- Purple-red shiny skin
- Tophi - large visible pumps composed of uric acid crystals
Drugs which cause hyperuricaemia (to worsen gout)
- Loop and thiazide diuretics
- Cytotoxic drugs
- Ciclosporin & Tacromilus
Gout treatment regimen - acute attack
- High dose NSAID (such as naproxen or diclofenac, NEVER aspirin)
or
Colchicine 500mcg BD-QDS, max 6mg per course. A repeat course should not be given within 3 days
or
Corticosteroids - short course
Prevention treatment should not be used during an acute attack as this may worsen or prolong attack
Gout treatment regimen - prevention in all patients
First line: Allopurinol
or
Febuxostat
Patients must report signs and symptoms of hypersensitivity with febuxostat.
There is an increased risk of cardiovascular death and all-cause mortality in gout.
Prevention treatment should not be used during an acute attack as this may worsen or prolong attack
Examples of xanthine oxidase inhibitors
- Allopurinol
- Febuxostat
Examples of uricosuric drugs
- Sulfinpyrazone
- Benzbromarone
Allopurinol mechanism of action
Inhibits xanthine oxidase, which prevents the formation of uric acid and lows uric acid levels
Allopurinol counselling and side effects,
- Take with or just after food, with a full glass of water
- Side effects: skin rash. If skin rash occurs stop, and re-introduce slowly if the skin rash is mild. If rash occurs again, completely stop
Allopurinol interactions
- Xanthine oxidase metabolises azathioprine and mercaptopurine. Therefore allopurnol interacts with azathioprine and mercaptopurine to cause them to accumulate. If the drugs are taken at the same time as allopurinol, their dose must be reduced by 25-50%
- Allopurinol increases the risk of hypersensitivty with ACE inhibitors and increases the risk of a skin rash with penicillins
