Gout Flashcards
what is gout
microcrystal synovitis caused by deposition of MSU in synovium
caused by chronic hyperuricaemia (uric acid > 450 umol/l)
acute mx of gout?
first-line: NSAIDs, colchicine
when should max dose NSAID be prescribed?
1-2 days after sx have settled
gastroprotection, e.g. PPI, also maybe indicated
how does colchicine work?
inhibits microtubule polymerisation by binding to tubulin, interfering with mitosis
also inhibits neutrophil motility and activity
colchicine disadvantages
slower onset of action
diarrhoea is main side effect
what is used if NSAIDs and colchicine are CI in gout acute mx?
oral steroids - usually prednisolone 15mg/day
what should be done if the pt is already taking allopurinol in gout?
continue with allopurinol (don’t stop it)
what are indications for urate-lowering hterapy?
give to all pt after first gout attack
particularly recommended if 2 or more attacks in 12mo, tophi, renal disease, uric acid renal stones, prophylaxis if on cytotoxics or diuretics
what is first-line in urate-lowering therapy?
allopurinol (100mg od with dose titrated every few weeks to aim for serum uric acid of <300umol/l)
lower initial doses if pt has reduced egfr
consider colchicine or NSAID cover (for 6mo)
when should urate-lowering therapy be delayed until?
best delayed until inflammation has settled as ult better discussed when pt is not in pain
what is second-line in urate-lowering therapy?
if allopurinol is not tolerated or ineffective, use febuxostat (xanthine oxidase inhibitor)
what is third-line in urate-lowering hterapy?
uricase (urate oxidase)
pegloticase (x1 infusion every 2wks) - persistent symptomatic and severe gout despite ULT
lifestyle modifications in gout?
reduce alc intake, avoid in acute attack
lose weight if obese
avoid purine-rich food (liver, kidney, seafood, mackerel/sardines, yeast products)
what drugs may be stopped in gout?
thiazides
why may losartan be suitable in gout management?
has specific uricosuric action so may be suitable for pt who have coexistent HTN
why may increasing vitamin C intake improve gout?
decreases serum acid levels
may be recommended either as supplements or normal diet
how long do gout flares last?
several days usualy
acute develop maximal intensity within 12h
features of a gout flare?
pain - often v sig
swelling
erythema
around 70% of first gout presentations affect?
1st MTP, but other commonly affected = ankle, wrist, knee
historically called podagra
what can happen if acute episodes of gout are left untreated?
more chronic joint issue
ix of gout?
IMMEDIATE
joint aspiration for synovial fluid analysis - needle-shaped -ve birefringent MSU crystals under polarised light (rule out sa)
CRP (rule out sa, in which case would be raised)
x-ray
LATER
uric acid - once acute episode has settled (~2wks) as may be high/normal/low during the attack
differentials for a hot, swollen joint
gout
septic arthritis
why are cytotoxic drugs a risk factor for gout?
they increase cell breakdown, releasing products degraded into uric acid -> hyperuricaemia (a rf for gout)
radiological features of gout?
early sign: joint effusion
punched-out erosions with sclerotic margins in a juxta-articular distribution
overhanging edges
soft tissue swelling
normal joint space until late disease
no periarticular osteopenia (unlike RA)
soft tissue tophi maybe
predisposing factors for gout?
decreased uric acid excretion: diuretics, ckd, lead toxicity
increased uric acid production: myelo/lymph proliferative disorder, cytotoxic dtugs, severe psoriasis
lesch-nyhan syndrome
what are features of lesch-nyhan syndrome?
hypoxanthine-guanine phosphoribosyl transferase deficiency
x-linked recessive - so only seen in men
features: gout, renal failure, neuro deficits, learning difficulties, self-mutiliation
