ic17 gout management Flashcards
diet and lifestyle factors associated with gout?
alcohol
sugary beverages (high fructose corn syrup)
dietary purines, eg red meat
sedentary lifestyle
obesity
what iss the special population gout
if gout present in male <30 or premenopausal women,
could suggest inherited enzyme defect OR presence of renal disease.
what are possible drug induced decreased uric acid clearance drugs
diuretics
organ transplant: cyclosporine, tacrolimus
low dose salicylates
TB drugs: ethambutol, pyramidazole
antiparkinsonian: levodopa
laxative abuse (alkalosis)
salt restriction
nicotinic acid
alcohol/ethanol
presentation of gout
usually monoarticular at the first MTP of great toe
wake up from sleep by pain
“hot burning pain” EXCRUCIATING pain
could be associated with lower temps = gout
swelling and discomfort may continue days to weeks thereafter…
how to make diagnosis for gout?
asymptomatic hyperuricemia alone ≠ gout
diagnosis based on the presence of monosodium urate crystals in:
- synovial fluid
- tissue sections of tophaceous deposits
what do the joint aspirate findings look like
colour: yellow
clarity: cloudy
viscosity: decreased
wbc: 2,000-50,000 cells/mm3
neutrophils >50%
gram stain: negative
crystals: positive (needle negative birefringent crystals)
NOTE THAT >50,000 suggests sepsis.
stages of gout
asymptomatic hyperuricemia:
men: plasma urate >6mg/dL
women: plasma urate >7mg/dL
acute gout: first attack
inter critical phase: asymptomatic
chronic gout: hyperuricemia, development of tophi/joint damage
recurrent gouty arhtritis
severe cases: interstitial renal disease, uric acid nephrolithiasis
initial phx management of acue gout flares?
initiate colchicine as soon as possible within 24 hours
other agents: oral nsaids or corticosteroids, otherwise intra-articular corticosteroids
no one tx is more effective than the other.
how to use ULTs?
initiate ULT (if indicated) after resolution of flares (2-4 weeks)
IF ALREADY ON ULT = do not discontinue during the lfare.
can also consider use of ULT without waiting for flare to resolve if
- patient does not want to return for tx
- patient not highly motivated for tx
- patient has frequnet attacks
non phx therapy for gout attacks
use topical ice
dose of colchicine for acute flares
1mg followed by 0.5mg one hour later
OR
0.5mg BD-TDS until flare resolves
SE of colchicine
n/v/diarrhoea
myopathy: muscle pain/weakness, dark urine
neuropathy: tingling sensation
pancytopenia: blood dyscrasia
caution w colchicine
use with renal or hepatic impairemnt can increase toxicity
use of 3a4 or pgp inhibitors can also increase toxicity:
- statins
- antiarrhymatics: amiodarone, verapamil, diltiazem
- rifampin
- macrolides
- azoles
c/i for colchicine
CRCL <30 avoid use.
criteria to initiating urate lowering therapy
≥2 acute flares
presence of TOPHUS
clinical / imaging of gouty arthropathy
history of urolithiasis
treatment target for gout
non-tophaceous gout = <360umol/L (6mg/dL)
tophaceous gout = <300umol/L (5mg/dL)
first line agents for ULT; which to choose?
xanthane oxidase inhibtors:
allopurinol and febuxostat
- allopurinol is cheaper but has more risk of hypersx SCAR compared to febuxostat.
- febuxostat has risk of MACE reactions and should caution in patients with CHD, HF…
allopurinol preferred in singpaore
considerations for use of uricosuric agents
probenecid is contraindicated in
- history of urolithiasis
- crcl <50
caution in patients with G6PD deficiency = risk of hemolytic anemia
dosing for allopurinol
initiation: ≤100mg/day (if ckd stage ≥3, or egfr <60, start at ≤50mg/day
increase in 50-100mg increments q2-8 weeks
maintain at >300mg/day (even for renal impairment)
max 800-900.day
dosing for febuxostat
initiation: ≤40mg/day (half dose if renally impaired)
titration: 80mg/day if treatment target not met after 2-4 weeks
dosing for probenecid
initiation: 250mg BD x 1 week, then 500mg BD
increase by 500mg q 4 weeks as tolerated,
maintenance: ≤2g/day
counselling point for probenecid
consume adequate vol of water <≥2L. to prevent risk of urolithiasis (kidney stone formation)
other counselling for prebencid (GAWIN DAWE)
keep urine pH >6 by giving potassium citrate
counselling point for all ULT
risk of SCAR
rare and serious adverse skin reaction
- if allergic reaction stop and seek help immeidately,
- if vv bad skin reaction with
flu like sx (high temp, body ache),
rash,
mouth ulcer/sore throat,
red/sore eyes,
stop drug and go a&e immeidately
what (and when) testing done for allopurinol
hla*b5801
more prevalent in han chinese
test if high risk, eg
- renal impairment, crcl <60
- use of diuretics
- older age
drug interactions with allopurinol
1) increase bone marrow suppression
by increasing conc of allo
- 6-mercaptopurine, azathioprine, cyclophosphamide
2) increase hypersx/toxicity of allopurinol
- ACEi, loop diuretics, thiazide diuretics, ampicillin, amoxicilin
3) allopurinol can increase concentration of
- CBZ, warfarin, theophylline (to monitor)
4) allopurinol can increase adverse effect/toxicity of PEGLOTICASE (recombinant pegylated uricase for gout)
gout prophylaxis against acute flares PHX
colchicine 0,5mg OD for 3-6 months
can also use low dose NSAIDs/oral corticosteroids (5-7.5mg prednisolone)
treatment duration of gout phx
if no flares ≥1 year and no tophi = considered remission,
conduct SDM on stopping treatment
what are high purine foods
asparagus, cauliflower
mushroom
red meat
anchovies & peanuts
durian
organ meat eg liver
