Allopurinol
Allopurinol (Zyloprim) is the only product on this shelf, available in 100 mg and 300 mg tablets for preventing gout flares and lowering uric acid during cancer therapy.
Key points
- Allopurinol blocks xanthine oxidase, the enzyme that converts hypoxanthine to xanthine and then to uric acid, cutting the body’s uric acid production at its source.
- The Zyloprim label warns that a skin rash may be followed by more severe hypersensitivity reactions, including Stevens-Johnson syndrome, generalised vasculitis, irreversible liver damage and, on rare occasions, death.
- NICE lists allopurinol as a first-line option for starting long-term, treat-to-target urate-lowering therapy in gout.
How does Allopurinol work?
By reducing uric acid at the enzyme level, allopurinol allows existing uric acid crystals to dissolve over time, which is what separates long-term gouty arthritis prevention from treating a single flare. NICE describes gout as a lifelong condition where sustained urate-lowering therapy eliminates crystals, shrinks tophi and protects joints from permanent damage. The same mechanism manages hyperuricaemia that spikes when tumour cells break down during cancer treatment, before the kidneys are overwhelmed. Zyloprim sits within Gout Treatment as the brand-name version of allopurinol.