Uricosuric medications
Clinical Pharmacology of Probenecid
| Probenecid | ||
|---|---|---|
| Mechanism of action | Competitively inhibits URAT1 & GLUT9 → decreased tubular reabsorption urate → increased uricosuria | |
| Pharmacokinetics | Hepatic metabolism Half-life 6–12 hours → BID dosing Decreases serum uric acid by ∼33% | |
| Adverse events | Preventable Acute gouty attacks: use prophylaxis Urate nephropathy: obtain baseline urine tests Urate nephrolithiasis: obtain baseline urine tests Relatively common Nausea, loss of appetite (10%) Dermatitis (5%) Headache, flushing Rare but serious Cytopenias, aplastic anemia Stevens–Johnson syndrome Anaphylaxis Nephrotic syndrome | |
| Contraindications or cautions to use | 24-hour urine collection with >800 mg uric acid History of uric acid nephrolithiasis CrCl <= 50 mL/minute (lack of efficacy) G6PD deficiency (risk of hemolytic anemia) Avoid with salicylates On Beers list of medications to avoid in elderly No hepatic adjustment required | |
| Drug interactions | Increases the half-life of many meds Probenecid increases serum concentration of many antibiotics, NSAIDs, dapsone, methotrexate, sulfonylureas, and heparin among others Aspirin diminishes effectiveness of probenecid | |
| Cost | With drug discount cards: $60/month (1000 mg BID dosing) |
BID, Twice a day; CrCl, creatinine clearance; G6PD, glucose-6-phosphate dehydrogenase; NSAIDs, nonsteroidal antiinflammatory drugs.
a Comparison of agents available in the United States; sulfinpyrazone and benzbromarone available outside the United States.
