Sulfinpyrazone Nitrofurantoin

SULFINPYRAZONE NITROFURANTOIN i renal excretion of nitrofurantoin, which i its efficacy in urinary tract infections Uncertain Watch for poor response to nitrofurantoin... 

Nitrofurantoin (Macrodanrin, Furadanrin, Macrobid) [Urinary Anri-infective] WARNING Pulm Rxns possible Uses Prevendon Rx UTE Action Bacteriostatic iaterferes w/ carbohydrate metabolism. Dose Adults. Suppression 50-100 mg/d PO Rx 50-100 mg PO qid Peds. Suppression 1-2 mg/kg/d ia 1—2 + doses, max 100 mg/d Rx 5—7 mg/lcg/24 h ia 4 + doses (w/ food/milk/antacid) Caution [B, +] Avoid w/ CrCl <60 ml ymin, PRG at term Contra Renal failure, infants <1 mo Disp Cperipheral neuropathy Interactions T Effects W/ probenecid, sulfinpyrazone 4 effects w/ antacids, quinolones EMS May affect glucose (hypoglycemia) may discolor urine OD May cause N/V give IV fluids... 

A study of the way the kidneys handle nitrofurantoin found that intravenous sulfinpyrazone 2.5 mg/kg reduced the secretion of nitrofurantoin by the kidney tubules by about 50%. Thi s reduction would be expected to reduce its urinary antibacterial efficacy, and the higher serum levels might lead to increased systemic toxicity, but there do not seem to be any reports suggesting that this represents a real problem in practice. The same situation would also seem likely with probenecid, but there do not appear to be any reports confirming this interaction. 

The clinical importance of both of these interactions is therefore uncertain, but it would seem prudent to be alert for any evidence of reduced antibacterial efficacy and increased systemic toxicity if either sulfinpyrazone or probenecid is used with nitrofurantoin. 

On theoretical grounds the efficacy and toxicity of nitrofurantoin may possibly be increased by probenecid and sulfinpyrazone. 

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