RIVUR - Randomized Intervention for Children with Vesicoureteral Reflux

Be at least 2 months of age, but less than 6 years (72 months) old when study medication begins
Have been diagnosed with his/her FIRST or SECOND urinary tract infection (UTI) with either fever or associated symptoms
Have been diagnosed with first UTI within 112 days prior to beginning study medication
Have been treated for the first UTI for 7 or more days with an effective drug
Have been diagnosed with Vesicoureteral Reflux (VUR) grade I-IV in at least one ureter, but not have Grade V VUR present
NOT have a history of other renal injury or disease
NOT have any other current or former medical conditions that could interfere with his/her response to the study medication
NOT have any allergies to sulfa medications or the study drug (Trimethoprim-Sulfamethoxazole), nor can there be a family history of serious reaction to sulfa medications
Meet a few additional eligibility requirements