Probenecid

Uricosuric·Musculoskeletal & Rheumatology

Gout prophylaxis (when allopurinol is contraindicated/failed)

PBSURICOSURICProbenecid AFT500 mg tabletS4+1

Max Dose

2000 mg/day

Half-life

4-17 h

Fluids

MANDATORY

Renal Adj.

INEFFECTIVE <50

Rapid Summary

Overview

Uricosuric agent. Lowers serum uric acid by blocking its reabsorption in the kidneys, forcing the body to pee out the uric acid.

Maximum Dose

Max 2000 mg/day (given in divided doses).

Clinical Focus

Requires excellent baseline renal function to work. Massive risk of forming kidney stones if oral fluids are not forced.

Bottom Line

Probenecid is a uricosuric agent for gout when allopurinol is not tolerated, but requires adequate renal function, high fluid intake, and is ineffective with eGFR < 30.

Formulation & Access

Brand Names

Probenecid AFT

Oral Routes

Tablets (500 mg).

Prescribing & PBS

Unrestricted General Benefit (S4).

Indications & Use

Primary

PBSTGA

Gout prophylaxis (when allopurinol is contraindicated/failed).

Off-Label

OFF

Boosting beta-lactam antibiotic levels.

Clinical Place

Second-line for chronic gout. Only useful for 'under-excreters' with healthy kidneys.

Quick reference

Class & Role

Uricosuric — Uricosuric agent.

Route / Formulation

Tablets (500 mg). (Probenecid AFT)

Usual Dose & Max

Start PO 250 mg BD for 1 week. Titrate up by 500 mg every 4 weeks. Maintenance usually 500-1000 mg BD. Max 2000 mg/day (given in divided doses).

Key Indication Doses

Chronic Gout: Start PO 250 mg BD for 1 week. Titrate up by 500 mg every 4 weeks. Maintenance usually 500-1000 mg BD. Penicillin Adjuvant: PO 500 mg QID (Used to boost penicillin blood levels for severe infections like neurosyphilis).

Best Uses

Probenecid is a uricosuric agent for gout when allopurinol is not tolerated, but requires adequate renal function, high fluid intake, and is ineffective with eGFR < 30.

Avoid / Cautions

History of uric acid kidney stones, acute gout flare, blood dyscrasias. Pregnancy Category B2.

Key Risks

Renal: Uric acid nephrolithiasis (kidney stones), acute uric acid nephropathy. Gastrointestinal: Nausea, vomiting, anorexia. Dermatological: Rash, hypersensitivity.

Key Interactions

Low-dose Aspirin antagonises the uricosuric effect of Probenecid. Do not use together. Penicillins and Cephalosporins (massively increases their blood levels and half-life). Methotrexate (reduces MTX clearance, spiking fatal toxicity).

Monitoring

Patient MUST drink 2-3 Litres of water daily to flush the uric acid out and prevent stone crystallization. Check eGFR (must be > 50). Monitor serum urate.

Clinical Pearl

Because Probenecid dumps massive amounts of uric acid into the urine, the urine becomes highly saturated. If the patient gets dehydrated, uric acid stones will form instantly. Prescribe a urinary alkaliser (e.g., Ural) concurrently to keep the uric acid dissolved.

Access

Probenecid AFT500 mg tablet

Brand: Probenecid AFT
Formulation: Tablets (500 mg)

Probenecid

Uricosuric·Musculoskeletal & Rheumatology

Gout prophylaxis (when allopurinol is contraindicated/failed)

PBSURICOSURICProbenecid AFT500 mg tabletS4+1

Max Dose

2000 mg/day

Half-life

4-17 h

Fluids

MANDATORY

Renal Adj.

INEFFECTIVE <50

Rapid Summary

Overview

Uricosuric agent. Lowers serum uric acid by blocking its reabsorption in the kidneys, forcing the body to pee out the uric acid.

Maximum Dose

Max 2000 mg/day (given in divided doses).

Clinical Focus

Requires excellent baseline renal function to work. Massive risk of forming kidney stones if oral fluids are not forced.

Bottom Line

Probenecid is a uricosuric agent for gout when allopurinol is not tolerated, but requires adequate renal function, high fluid intake, and is ineffective with eGFR < 30.

Formulation & Access

Brand Names

Probenecid AFT

Oral Routes

Tablets (500 mg).

Prescribing & PBS

Unrestricted General Benefit (S4).

Indications & Use

Primary

PBSTGA

Gout prophylaxis (when allopurinol is contraindicated/failed).

Off-Label

OFF

Boosting beta-lactam antibiotic levels.

Clinical Place

Second-line for chronic gout. Only useful for 'under-excreters' with healthy kidneys.

Quick reference

Class & Role

Uricosuric — Uricosuric agent.

Route / Formulation

Tablets (500 mg). (Probenecid AFT)

Usual Dose & Max

Start PO 250 mg BD for 1 week. Titrate up by 500 mg every 4 weeks. Maintenance usually 500-1000 mg BD. Max 2000 mg/day (given in divided doses).

Key Indication Doses

Best Uses

Probenecid is a uricosuric agent for gout when allopurinol is not tolerated, but requires adequate renal function, high fluid intake, and is ineffective with eGFR < 30.

Avoid / Cautions

History of uric acid kidney stones, acute gout flare, blood dyscrasias. Pregnancy Category B2.

Key Risks

Renal: Uric acid nephrolithiasis (kidney stones), acute uric acid nephropathy. Gastrointestinal: Nausea, vomiting, anorexia. Dermatological: Rash, hypersensitivity.

Key Interactions

Monitoring

Patient MUST drink 2-3 Litres of water daily to flush the uric acid out and prevent stone crystallization. Check eGFR (must be > 50). Monitor serum urate.

Clinical Pearl

Access

Probenecid AFT500 mg tablet

Brand: Probenecid AFT
Formulation: Tablets (500 mg)