Class Explorer · Pain & inflammation
Gout agents
Two entirely separate jobs that are constantly confused: putting out the fire of an acute attack, and lowering urate over months so the fires stop.
Members
AllopurinolLowers urate over months, and does nothing for the attack in front of you.ColchicineWorks if you start it early, and poisons you if the kidneys and CYP3A4 are against you.
Also in this class: Febuxostat · Probenecid · Pegloticase. Full pages arrive as the library grows.
Compare the members
Allopurinol
- Job
- Lower urate
- Timing
- Long term; continue through flares
Colchicine
- Job
- Treat inflammation
- Timing
- Start within hours of a flare
Shared across the class
- Indications
- Gout
- Adverse effects
- Gastrointestinal upset · Rash, occasionally severe (allopurinol)
- Contraindications
- Agent-specific
- Monitoring
- Serum urate against a target, usually below 360 µmol/L and lower with tophi · Renal function · Rash, which with allopurinol is stopped on first appearance
What makes each agent different
- Allopurinol is urate-lowering and does nothing for an acute attack; started during one it can prolong it, though an established prescription is never stopped mid-flare.
- Colchicine is anti-inflammatory and does nothing to urate. Its usefulness collapses if it is started late: hours matter.
- Every urate-lowering start needs anti-inflammatory prophylaxis alongside it for months, because falling urate mobilises crystals and provokes flares.
Allopurinol hypersensitivity syndrome is rare and can be fatal; the HLA-B*5801 allele carries much of the risk and is screened for in some populations.
Colchicine is renally and hepatically cleared and interacts sharply with clarithromycin, verapamil and statins. Toxicity presents as diarrhoea before anything else.
Last reviewed 2026-08-16 · Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed.