Gout

Question 1

what is gout?

Answer 1

Inflammatory arthritis
microcrystal synovitis caused by the deposition of monosodium urate monohydrate in the synovium

Question 2

What causes gout?

Answer 2

chronic hyperuricaemia (uric acid > 0.45 mmol/l)W

Question 3

What drugs can cause gout?

Answer 3

diuretics - thiazides, furosemide
ciclosporin
alcohol
cytotoxic agents
pyrazinamide
aspirin

Question 4

how long does an episode of gout take to come on, and how long does it usually last?

Answer 4

acute episodes typically develop maximal intensity with 12 hours

episodes last several days

Question 5

Main features of gout flare

Answer 5

pain
swelling
erythema

Question 6

Most common joint to be affected first in gout

Answer 6

1st metatarsophalangeal (MTP) joint

Question 7

Other joints (excluding MTP) which can develop gout

Answer 7

Ankle
Knee
Wrist

Question 8

If untreated repeated acute episodes of gout can damage the joints resulting in a more chronic joint problem. TRUE/FALSE?

Answer 8

TRUE

Question 9

How can gout be identified on Synovial fluid analysis

Answer 9

needle shaped
negatively birefringent
monosodium urate crystals
under polarised light

Question 10

When should uric acid levels be checked in relation to the acute gout episode

Answer 10

once the acute episode has settled down
(typically 2 weeks later)

Question 11

XR findings seen in gout

Answer 11

joint effusion
‘punched-out’ erosions with sclerotic margins
preservation of joint space
eccentric erosions
no periarticular osteopenia
soft tissue tophi

Question 12

Acute gout management options

Answer 12

NSAIDs or colchicine are first-line
PPI if starting these

Question 13

Explain the mechanism of action of colchicine

Answer 13

inhibits microtubule polymerization by binding to tubulin, interfering with mitosis.

Also inhibits neutrophil motility and activity

Question 14

Colchicine has a slower onset of action than NSAIDs. TRUE/FALSE?

Answer 14

TRUE

Question 15

Colchicine should be used with caution in renal impairment. Explain when the dose should be reduced and when colchicine is contraindicated

Answer 15

reduce dose if eGFR is 10-50 ml/min
avoid if eGFR < 10 ml/min BNF

Question 16

Main side effect of colchicine

Answer 16

diarrhoea

Question 17

What can be used if NSAIDs and colchicine are contraindicated?

Answer 17

oral steroids
- prednisolone 15mg/day is usually used

another option is intra-articular steroid injection

Question 18

if the patient is already taking allopurinol during an acute gout flare, should it be continued whilst they take NSAIDs or colchicine?

Answer 18

Yes

Question 19

When should urate lowering therapy be offered to patients with gout?

Answer 19

British Society of Rheumatology Guidelines advocate:
- after the first attack of gout

ULT is particularly recommended if:
>= 2 attacks in 12 months
tophi
renal disease
uric acid renal stones
prophylaxis if on cytotoxics or diuretics

Question 20

When should urate lowering therapy be started in relation to an acute attack

Answer 20

should not be started until 2 weeks after an acute attack,

Question 21

First line urate lowering therapy

Answer 21

Allopurinol

Question 22

Explain how allopurinol is initiated

Answer 22

Start with 100 mg od
dose titrated every few weeks to aim for a serum uric acid of < 360 µmol/l
Lower initial dose of allopurinol if patient has reduced eGFR
Colchicine cover can be considered when starting allopurinol

Question 23

When may a lower target uric acid level (<300 µmol/L) be considered?

Answer 23

patients who have:
- tophi
- chronic gouty arthritis
- OR continue to have ongoing frequent flares despite having a uric acid <360

Question 24

Second line agent when allopurinol is not tolerated

Answer 24

Febuxostat

Question 25

Mechanism of action of allopurinol and febuxostat

Answer 25

Xanthine oxidase inhibitor

Question 26

In cases of gout refractory to allopurinol and febuxostat, what other agents could be tried?

Answer 26

1. uricase (urate oxidase) [THINK RASBURICASE!]
2. pegloticase (polyethylene glycol modified mammalian uricase)
   - given as infusion once every two weeks

Question 27

Important lifestyle modifications in the treatment of gout

Answer 27

reduce alcohol intake and avoid during an acute attack
lose weight if obese
avoid food high in purines e.g. Liver, kidneys, seafood, oily fish (mackerel, sardines) and yeast products

Question 28

Medication changes which may help in the treatment of gout

Answer 28

stop precipitating drugs (e.g. thiazides)

losartan = specific uricosuric action
=> suitable for the patients who have coexistent hypertension

Question 29

Two main mechanisms of high uric acid

Answer 29

Excess production
- myeloproliferative/lymphoproliferative disorder
- cytotoxic drugs
- severe psoriasis

Reduced excretion
- drugs: diuretics
- chronic kidney disease
- lead toxicity

Question 30

Eponymous syndrome associated with gout

Answer 30

Lesch-Nyhan syndrome:
- hypoxanthine-guanine phosphoribosyl transferase (HGPRTase) deficiency
- x-linked recessive
Features:
- gout, renal failure, neurological deficits, learning difficulties, self-mutilation