Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.
2 min synopsisUK scopeSources checked 27 Aug 2026Clinical review pending
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Serious hypersensitivity needs immediate action
A new rash with fever, facial oedema, mucosal ulceration, blistering, eosinophilia, hepatitis or kidney injury after allopurinol or febuxostat may represent DRESS, Stevens-Johnson syndrome or toxic epidermal necrolysis.
Action: Stop the suspected urate-lowering medicine immediately, do not rechallenge after a severe reaction, assess airway, mucosa, skin detachment and organs, and arrange same-day emergency dermatology and medical care while documenting the exact medicine and reaction.
Synopsis
Use shared decisions and a treat-to-target strategy to dissolve monosodium-urate crystals, prevent flares and tophi, titrate allopurinol or febuxostat safely and sustain monitoring across renal, cardiovascular and reproductive contexts.
Urate-lowering therapy is crystal-dissolving treatment, not an analgesic. Benefits require a serum-urate target, gradual titration, flare prophylaxis and continuation after the patient feels well.
Offer treat-to-target ULT for multiple or troublesome flares, CKD stages 3–5, diuretic therapy, tophi or chronic gouty arthritis; discuss it after a first or later flare in other patients.
NICE usually starts ULT two to four weeks after a flare has settled; frequent flares can justify starting during an attack while adequate anti-inflammatory treatment and prophylaxis continue.
Key red flags
Rash, mucosal pain, blistering, facial swelling, fever or systemic illness after allopurinol requires immediate permanent cessation pending urgent assessment.
Allopurinol hypersensitivity
New rash with fever, facial swelling, mucosal disease or internal-organ injury after exposure is an emergency and prohibits rechallenge after severe reaction.
Investigation priorities
01
First-line baseline urate and safety bloodsFirst stepFirst line
Confirm the treatment baseline and identify prescribing constraints.
Management branches
First-line eligibilityOffer or discuss lifelong crystal dissolution
Gout is confirmed and the acute attack has been reviewed.
Offer ULT for troublesome recurrence, CKD stages 3–5, diuretic therapy, tophi or chronic gouty arthritis and discuss it with other patients after any flare.
Explain targets, early mobilisation flares, prophylaxis, likely lifelong duration and why symptom freedom alone is not crystal clearance.
First-line selectionChoose allopurinol or febuxostat safely
The patient elects to begin treat-to-target urate-lowering therapy.
Key medicines
AllopurinolStart 100 mg orally once daily after food in most adults; consider 50 mg once daily in advanced renal impairment. Increase commonly by 100 mg every 2 to 4 weeks against monthly serum urate, up to the licensed maximum 900 mg daily when necessary and tolerated.
FebuxostatGive 80 mg orally once daily with or without food; if serum urate remains above 357 micromol/L after 2 to 4 weeks, consider increasing to 120 mg once daily.
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.