ic17 gout management

Question 1

diet and lifestyle factors associated with gout?

Answer 1

alcohol
sugary beverages (high fructose corn syrup)
dietary purines, eg red meat

sedentary lifestyle
obesity

Question 2

what iss the special population gout

Answer 2

if gout present in male <30 or premenopausal women,

could suggest inherited enzyme defect OR presence of renal disease.

Question 3

what are possible drug induced decreased uric acid clearance drugs

Answer 3

diuretics

organ transplant: cyclosporine, tacrolimus

low dose salicylates

TB drugs: ethambutol, pyramidazole

antiparkinsonian: levodopa

laxative abuse (alkalosis)

salt restriction

nicotinic acid

alcohol/ethanol

Question 4

presentation of gout

Answer 4

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…

Question 5

how to make diagnosis for gout?

Answer 5

asymptomatic hyperuricemia alone ≠ gout

diagnosis based on the presence of monosodium urate crystals in:
- synovial fluid
- tissue sections of tophaceous deposits

Question 6

what do the joint aspirate findings look like

Answer 6

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.

Question 7

stages of gout

Answer 7

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

Question 8

initial phx management of acue gout flares?

Answer 8

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.

Question 9

how to use ULTs?

Answer 9

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

Question 10

non phx therapy for gout attacks

Answer 10

use topical ice

Question 11

dose of colchicine for acute flares

Answer 11

1mg followed by 0.5mg one hour later

OR

0.5mg BD-TDS until flare resolves

Question 12

SE of colchicine

Answer 12

n/v/diarrhoea

myopathy: muscle pain/weakness, dark urine
neuropathy: tingling sensation
pancytopenia: blood dyscrasia

Question 13

caution w colchicine

Answer 13

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

Question 14

c/i for colchicine

Answer 14

CRCL <30 avoid use.

Question 15

criteria to initiating urate lowering therapy

Answer 15

≥2 acute flares

presence of TOPHUS

clinical / imaging of gouty arthropathy

history of urolithiasis

Question 16

treatment target for gout

Answer 16

non-tophaceous gout = <360umol/L (6mg/dL)
tophaceous gout = <300umol/L (5mg/dL)

Question 17

first line agents for ULT; which to choose?

Answer 17

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

Question 18

considerations for use of uricosuric agents

Answer 18

probenecid is contraindicated in
- history of urolithiasis
- crcl <50

caution in patients with G6PD deficiency = risk of hemolytic anemia

Question 19

dosing for allopurinol

Answer 19

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

Question 20

dosing for febuxostat

Answer 20

initiation: ≤40mg/day (half dose if renally impaired)

titration: 80mg/day if treatment target not met after 2-4 weeks

Question 21

dosing for probenecid

Answer 21

initiation: 250mg BD x 1 week, then 500mg BD

increase by 500mg q 4 weeks as tolerated,

maintenance: ≤2g/day

Question 22

counselling point for probenecid

Answer 22

consume adequate vol of water <≥2L. to prevent risk of urolithiasis (kidney stone formation)

Question 23

other counselling for prebencid (GAWIN DAWE)

Answer 23

keep urine pH >6 by giving potassium citrate

Question 24

counselling point for all ULT

Answer 24

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

Question 25

what (and when) testing done for allopurinol

Answer 25

hla*b5801
more prevalent in han chinese

test if high risk, eg
- renal impairment, crcl <60
- use of diuretics
- older age

Question 26

drug interactions with allopurinol

Answer 26

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)

Question 27

gout prophylaxis against acute flares PHX

Answer 27

colchicine 0,5mg OD for 3-6 months

can also use low dose NSAIDs/oral corticosteroids (5-7.5mg prednisolone)

Question 28

treatment duration of gout phx

Answer 28

if no flares ≥1 year and no tophi = considered remission,

conduct SDM on stopping treatment

Question 29

what are high purine foods

Answer 29

asparagus, cauliflower
mushroom
red meat
anchovies & peanuts
durian
organ meat eg liver