IC17 Gout

Question 1

goals of treatment

Answer 1

1. Provide rapid, safe & effective pain relief
2. Reduce future attacks (reduce serum urate)

Question 2

patho of gout

Answer 2

basically, incr in purine/ uric acid which leads to urate crystal formation in synovial fluid

Question 3

pharmacotherapy approach in gout (first acute gouty arthritis / subsequent flares)

Answer 3

Colchicine preferred if present within 24-36h;
Other choices: NSAIDs, corticosteroids

Question 4

clinical presentation

Answer 4

severe pain, usually monoarticular at 1st MTP of great toe

Question 5

Treatment goal for non-tophaceous gout in ULT

Answer 5

< 360 umol/L (6mg/dL)

Question 6

Dose for colchicine

Answer 6

Once-off: Loading dose 1mg, f/b 0.5mg 1h later
OR
0.5mg BD or TDS, until acute flare resolves
Max: 1.5mg/day

Question 7

Dose for NSAIDs

Answer 7

Celecoxib 400mg loading, f/b 200mg BD
Max: 400mg/day

Question 8

Dose for corticosteroids

Answer 8

Prednisolone 30-40mg/day OR 0.5mg/kg/day

Question 9

When to initiate ULT

Answer 9

Any of following:
- Hx of urolithiasis
- Presence of tophus
- 2 or more acute gout per year
- Clinical/ imaging finding of gouty arthropathy

Question 10

Transporters that reabsorb uric acid in kidney

Answer 10

URAT-1, GLUT-9

Question 11

MOA of pegloticase (not avail in SG)

Answer 11

Incr uric acid metabolism; Converts uric acid to allantoin

Question 12

MOA of lesinurad (not avail in SG)

Answer 12

Incr uric acid excretion; Selective URAT1 inhibitor

Question 13

Dose for allopurinol

Answer 13

• initiation: ≤ 100mg/day [CKD stage ≥ 3: ≤ 50mg/day]
• titration: 50-100 mg increments q2-8 wks
• Usual maintenance: > 300mg/day [ok for renal impairment]
• max: 800-900 mg/day [normal renal fn]

Question 14

Why is HLA-B *5801 testing not routinely done prior to allopurinol initiation?

Answer 14

• low PPV
• lack of cost-effective alternative ULT

Question 15

Who would benefit from HLA-B *5801 testing more?

Answer 15

higher risk of allopurinol-induced SCAR e.g. renal impairment or older age.

Question 16

ULT at higher risk of SCAR

Answer 16

allopurinol, febuxostat

Question 17

Medication Review of Existing Meds

Answer 17

• Switch hydrochlorothiazide to alternative antihypertensive -> HCTZ decreases urate excretion
• Use losartan preferentially as antihypertensive
  -> ACEi (enalapril & captopril) & ARB (losartan) has uricosuric effect