Gout in practice (Louise) Flashcards
What is gout?
a type of arthritis where crystals form inside and around joints rapid onset (6-12hrs)
symptoms of gout
severe pain
swelling
warmth
tenderness in joint
Where is gout most commonly found?
1st metetarsophalangeal joint
areas of body you can find gout
big toe midfoot ankle knee fingers wrist elbow
How many joints does gout affect usually?
monoarticular - affects one joint
What is tophus?
a build up of crystals at the surface of the joint
What is pseudo-gout?
non-urate crystal induced gout
septic arthritis
if systemically unwell and painful, hot, swollen joint
refer immediately for emergency joint aspiration and culture
can be fatal if recognised late
risk factors for gout
sustained increase in serum urate (sUA) age (O50) male renal impairment hypertension drugs (diuretics) tophi chronic arthritis alcohol consumption
What is gold standard for diagnosos of gout?
urate crystals in fluid aspirated from joint (in secondary care)
When should gout be referred to secondary care?
- septic arthritis suspected (urgently)
- unresponsive to uric acid lowering or persistent symptoms after max NSAIDs
- complications relating to gout (neuropathy)
- persists despite uric acid levels being lowered
- young onset (<30yrs)
- pregnancy
- diagnostic uncertainty
acute gout management 1st/2nd/3rd line
1st line - NSAID full dose (or COX-2 inhibitor) AND PPI
2nd line - colchicine
3rd line - corticosteroids
acute gout management
- start antiinflammatory/analgesic straight away and continue for 1-2 weeks (24-48hrs after the attack has resolved)
- elevate joint/rest/keep cool/avoid trauma to joint
NSAIDs that can be used
any at max dose
indometacin
diclofenac
naproxen
When to avoid NSAIDs
in HF
active GI ulcer
impaired renal function
colchicine dose
500mcg 2-3 times a day until symptoms relieved or until diarrhoea/vomiting occurs
max dose of colchicine
500mcg QDS
Why is colchicine dose limited?
by diarrhoea and vomiting
When is colchicine most effective?
if taken within 12-24hrs of an attack
cautions with colchicine
narrow therapeutic window
very toxic in overdose
when to reduce dose/inc dosing interval of colchicine
in elderly
When is colchicine useful?
warfarin - can’t take NSAIDs and warfarin together
renal impairment - can’t give NSAIDs, adjust dose (caution)
HF - can’t take NSAID
When to avoid colchicine in renal impairment?
eGFR < 10 (end stage)
max dose of colchicine per acute treatment course
max 6mg
don’t repeat within 3 days
colchicine interactions
caution/low dose with CYP450 3A4 inhibitors (clarithromycin, erythromycin)
caution in renal impairment and statins - report myopathy and rhabdomylosis
3rd line option
corticosteroids
-> can’t take NSAIDs and colchicine not tolerated
How are steroids given for monoarthritis gout?
intra-articular injection
IM
oral
What steroids are used?
methylprednisolone
hydrocortisone acetate
triamcinolone oral prednisolone
oral prednisolone dose
20-40mg daily for 5 days
steroids given by IM injection
methylprednisolone
triamcinolone
lifestyle factors
reduce alcohol intake (especially purine rish - beer)
reduce purine rich foods (shellfish/meat)
What risk should be reviewed annually?
CV risk
-> connection between sUA and CVD
What drugs can induce gout?
low dose aspirin (interferes with uric acid excretion) antihypertensives - DIURETICS - beta blockers - ACEI - losartan/CCBs (dec sUA)
What information to give to patients?
- causes/consequences of gout
- how to manage acute attacks
- aims/objectives of treatment
- lifestyle advice (diet, alcohol, obesity)
When and what to review after acute attack?
review 4-6 weeks after
- check sUA and renal function
- check lifestyle factors
- assess CV risk factors (and treat)
- review prescribed meds (diuretics)
- discuss urate lowering therapy (ULT)
When is ULT (urate lowering therapy) important?
- 2+ attacks in 12mths
- tophaceous gout/gouty erosions on x-ray (tophi)
- uric acid renal stones (kidney stones)
- CKD and gout
- continuing diuretics (HF) and gout
When not to start chronic gout management?
during an attack
but continue if already established therapy and an attack occurs
management of chronic gout 1st/2nd/3rd line
1st line - allopurinol
2nd line - febuxostat
3rd line - benzbromarone (specialist only)
co-prescribing for chronic gout management
low dose colchicine 500mg OD/BD
OR
low dose NSAID
-> up to 6 months to prevent acute flare
What is the aim of ULT (urate lowering therapy?
reduce and maintain serum uric acid leves at or below target level
prevent further urate crystal formation
dissolve existing crystals
When to start allopurinol?
at least 1-2 weeks from last attack when newly starting
dose of allopurinol
low dose 50-100mg/day
When to monitor sUA on allopurinol?
monthly
How is allopurinol titrated?
titrate up by 100mg to achive serum urate below target levels (<300micro moles/L)
usual allopurinol dose
300-600mg daily
-> 300mg in divided doses
When to adjust dose of allopurinol?
renal impairment
What not to prescribe with allopurinol
azathioprine
-> inhibits metabolism of azathiporine, accumulation of toxic metabolites
s/e of allopurinol
rash GI intolerance (take after meals)
rash with allopurinol
- if rash occurs stop and seek med advice
- when rash resolved if it was mild, can gradually introduce again
- but discontinue if rash returns
When to start febuxostat?
at least 1-2 weeks from last attack when nwely starting
dose of febuxostat
low dose 80mg to start
increase in response to serum urate blood tests
max dose of febuxostat
120mg daily
cautions with febuxostat
liver impairment
thyroid disorders
IHD
HF
what to avoid with febuxostat
azathioprine
mercaptopurine
s/e with febuxostat
GI
abnormal LFT
oedema
When should febuxostat be stopped immediately?
if hypersensitivity occurs
- Stevens-Johnson syndrome
- acute anaphylactoid shock/rxn
- > discontinue and do not start again
3rd line options for gout
drugs that increase uric acid excretion - uricosuric drugs
- benzbromarone (unlicenced, parallel import)
- sulfinpyrazone
- probenecid (unlicenced)
What is the target for sUA?
< 300 micro moles/L
What is the dose for when sUA is at target/no tophu/attacks stopped?
reduce ULT dose to maintain sUA at 300-360
How often should ULT be measured when target sUA reached/no tophi/no attacks?
annually
