Probenecid

How it works

It inhibits renal tubular reabsorption of urate, increasing uric acid excretion and lowering serum urate; it also reduces renal tubular secretion of some drugs.

Prescribing in practice

• Probenecid should not be started during an acute gout attack and can precipitate flares when initiated, so it is begun once acute inflammation has settled with appropriate flare prophylaxis.
• Generous fluid intake, and sometimes urine alkalinisation, is advised to reduce the risk of urate stone formation.
• It is ineffective in significant renal impairment and reduces the renal excretion of several drugs, raising their plasma levels.

Monitoring

Monitor serum urate, renal function, and for gout flares after initiation and dose changes.

Counselling the patient

• Drink plenty of fluids to help prevent kidney stones.
• A flare of gout may occur when starting; do not stop the medicine but follow the flare-treatment advice given.
• Tell your clinician and pharmacist about all other medicines, as interactions are common.

Evidence & guidelines

Probenecid is an established uricosuric option for urate-lowering therapy in gout, as reflected in NICE guidance on gout management.