Gout Flashcards
What is gout? What are the causes?
an abnormality of uric acid metabolism resulting in deposition of uric acid/urate crystals in the joints, soft tissue and urinary tract
- hyperuricaemia = > 0.42 mmol/L (men) and >0.36 mmol/L (women)
What foods are high and moderate in purines?
high
- alcoholic beverages,
- seafoods = herring, sardines, trout, haddock
- meats = bacon, turkey, venison
moderate
- meats = beef, chicken, pork, ham, duck
- shellfish = crab, globefish, oysters, shrimp
What are the symptoms of gout?
pain in the affected joints and reddening of the surrounding skin
- feels hot and looks shiny
attacks commonly starts during the night or early morning and reaches a peak within a few hours
- first attack is most commonly in the big toe
- can also affect the knees, elbows, wrists and small joints of the hands
can become tophaceous
- visible and/or palpable deposits of uric acid crystals in r around the joints and subcutaneous tissues
What are the treatments for gout during an attack vs prophylaxis of an attack?
during
- NSAIDs = diclofenac, indomethacin, ketoprofen, suldinac and etoricoxib
- colchicine
- corticosteroids
- monoclonal steroids = canakinumab
prophylaxis
- allopurinol
- febuxostat
- uricosurics = sulfinpyrazone,
How should NSAIDs be used? What should be monitored?
start on a high dose and titrate down
typically required for 7-14 days
avoid in renal impairment and CVD
monitor - renal function, LFTs
How should colchicine be used? What is the dose? What are the side effects? What should be monitored?
should be started as soon as symptoms start
- becomes less effective over time
500mcg up to 4 times a day
- max 6g = 2000mcg/2mg per day for 3 days
can be used in CVD instead of NSAIDs
should be reduced in the elderly and renal insufficiency
- avoid in eGFR < 10ml/min/1.73
side effects - nausea, vomiting, abdominal pain
= excessive doses may cause diarrhoea, GI haemorrhage, renal damage and blood disorders
monitor - FBC, LFTs, renal function
How should corticosteroids be used? What are the advantages? What are the side effects?
can be given orally or via intra-articular injection into the affected joints
- if one or a few joints are affected
= max 4 times a day
avoid bone infection
- must use aseptic techniques to avoid infection
can be used in renal impairment
When is canakinumab used?
is used for asymptomatic treatment of frequent gout arthritic attacks for patients who have not responded adequately to treatment with NSAIDs or colchicine
- with other treatment failure
What are lifestyle modifications to treat gout?
weight reduction
reduced alcohol consumption
reduced dietary purine intake
increasing water intake
What is allopurinol? When is it used? What are the requirements and cautions?
xanthine oxidase inhibitor
- inhibits the formation of uric acid from precursor xanthines
- 100mg OD
should be never be used during an acute attack
- must be started at least 1-2 weeks after
- require prophylactic colchicine or NSAIDs for at least one month to prevent an attack when initiating treatment
- taken after food
dose should be reduced in renal failure as its metabolite has a prolonged half life
require adequate fluid intake of at least 2-3L
side effects - rash = must withdraw treatment if rash reoccurs after passing treatment
cannot be taken with azathioprine (RA drug)
What is febuxostat? What are the side effects? What are the cautions?
a selective inhibitor of xanthine oxidase and decreases serum uric acid concentration
- 80mg OD
side effects - nausea, diarrhoea, headache, rash and LFT abnormalities
CI - heart failure, ischaemic heart disease
What are uricosurics? What do they do? What are the requirements? What are the cautions?
increase uric acid secretion by blocking tubular reabsorption of urate
- sulfinpyrazone
must be used alongside prophylactic colchicine or NSAIDs
require adequate fluid intake of at least 2-3L
CI - renal failure, those who have had uric acid stones in the kidney
risk of formation of urate crystals in the urine
risk of deposition of crystals in the tubules, pelvis and ureter
- can cause renal colic or deterioration of renal function
What must be avoided in gout?
aspirin and salicylates
- inhibit uric acid excretion
What are the causes of gout (pathophysiology)?
under excretion of uric acid
- renal insufficiency
- obesity, hypertension, hyperlipidaemia
- lead toxicity, alcohol, glucose-6-phosphatase deficiency
- drug therapy = thiazides, low dose aspirin (75mg)
overproduction of uric acid
- disease of high cell turnover (cancer, psoriasis)
- cytotoxic drugs
- dietary purines (alcohol, seafoods, meat)
- increased de novo purine synthesis
