ANTURANE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for ANTURANE (ANTURANE).
Uricosuric agent; inhibits renal tubular reabsorption of uric acid, increasing uric acid excretion and lowering serum urate levels.
| Metabolism | Primarily hepatic oxidation and glucuronidation; minor CYP450 involvement. |
| Excretion | Renal excretion: approximately 50% of the dose as unchanged drug and its active sulfide metabolite via glomerular filtration and tubular secretion; biliary/fecal: ~30%, primarily as metabolites. |
| Half-life | Terminal elimination half-life is approximately 4–6 hours for the parent drug; active sulfide metabolite has a half-life of 12–16 hours. Clinically, twice-daily dosing maintains therapeutic levels. |
| Protein binding | 99% bound, primarily to albumin. |
| Volume of Distribution | 0.15–0.3 L/kg, indicating limited extravascular distribution; primarily remains in plasma and extracellular fluid. |
| Bioavailability | Oral: Approximately 90% absorbed, but extensive first-pass metabolism reduces systemic bioavailability of parent drug to 30–40%; active sulfide metabolite contributes to efficacy. |
| Onset of Action | Oral: Onset of uricosuric effect occurs within 24–48 hours, with peak effect in 1–2 weeks. |
| Duration of Action | Uricosuric effect persists for 8–12 hours after a single dose; sustained effect with continuous therapy. Clinical monitoring required for urate lowering. |
200-400 mg orally twice daily
| Dosage form | TABLET |
| Renal impairment | Contraindicated if CrCl <30 mL/min. For CrCl 30-50 mL/min, reduce dose by 50%. For CrCl >50 mL/min, no adjustment. |
| Liver impairment | Child-Pugh A: no adjustment. Child-Pugh B: reduce dose by 50%. Child-Pugh C: avoid use. |
| Pediatric use | Not recommended for use in pediatric patients due to lack of safety and efficacy data. |
| Geriatric use | Start at low end of dosing range (200 mg twice daily); monitor renal function. Caution due to increased sensitivity and renal impairment. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for ANTURANE (ANTURANE).
| Breastfeeding | Sulfinpyrazone is excreted into human milk in small amounts. The milk-to-plasma (M/P) ratio is not well established but is likely low (<0.2). Due to potential adverse effects in the nursing infant (e.g., bleeding risk, interference with platelet function), caution is recommended. The benefits of breastfeeding should be weighed against the potential risks, and alternative therapies considered. |
| Teratogenic Risk | Anturane (sulfinpyrazone) is a uricosuric agent. There are no adequate and well-controlled studies in pregnant women. In animal studies, no teratogenic effects were observed at doses up to 10 times the human dose. However, due to its potential to inhibit platelet aggregation, use during pregnancy, especially near term, may increase the risk of maternal and fetal hemorrhage. First trimester: No specific fetal risks identified, but caution advised. Second trimester: Risks unclear; avoid unless necessary. Third trimester: Potential for premature closure of ductus arteriosus (unlikely as it is not an NSAID) and bleeding risk; avoid near term. |
■ FDA Black Box Warning
None.
| Serious Effects |
["Severe renal impairment (CrCl <50 mL/min)","History of hypersensitivity to sulfinpyrazone or sulfonamides","Active peptic ulcer disease","Blood dyscrasias","Uric acid nephropathy or stone formation"]
| Precautions | ["Acute gouty attacks may occur during initiation; prophylactic colchicine or NSAIDs recommended","Monitor renal function; dose adjustment in renal impairment","Avoid in patients with high urinary uric acid output to prevent uric acid stones","May potentiate warfarin; monitor INR","Cross-allergenicity with sulfonamides possible"] |
| Food/Dietary | Avoid alcohol as it increases uric acid levels and may decrease drug efficacy. Maintain adequate hydration; avoid excessive intake of high-purine foods (e.g., organ meats, sardines, anchovies) to help control gout. |
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| Fetal Monitoring | Monitor complete blood count (CBC) for thrombocytopenia and other cytopenias. Assess renal function (serum creatinine, BUN) and liver function tests periodically. Monitor for evidence of bleeding (e.g., bruising, petechiae) in both mother and fetus/infant. During pregnancy, consider fetal ultrasound if concerns about growth or well-being arise. |
| Fertility Effects | Sulfinpyrazone may inhibit prostaglandin synthesis, which could theoretically affect ovulation and implantation. However, clinical data on fertility effects are lacking. No specific studies have been conducted regarding its impact on human fertility. In animal studies, no impairment of fertility was observed at clinically relevant doses. |
| Clinical Pearls | Anturane (sulfinpyrazone) is a uricosuric agent used for chronic gout. It is contraindicated in patients with peptic ulcer disease due to GI irritation. Monitor renal function and uric acid levels. Avoid use in patients with a history of uric acid stones; maintain high fluid intake to prevent stone formation. Not effective in acute gout attacks. Discontinue at least 48 hours before surgery to avoid bleeding risk due to antiplatelet effects. |
| Patient Advice | Take with food or milk to reduce stomach upset. · Drink at least 8 glasses of water daily to prevent kidney stones. · Avoid aspirin and other salicylates as they reduce drug effectiveness. · Report any signs of bleeding (bruising, black stools) or stomach pain. · Do not stop suddenly without consulting your doctor. · This drug is not for acute gout attacks; continue other medications as prescribed. |