BK Treatment Study

Inclusion Criteria: * Living and cadaveric kidney transplant recipients over the age of 18 years with BK viremia Exclusion Criteria: * Female patients of childbearing age who are pregnant or in whom adequate contraception cannot be maintained. * Patients with active infections, history of malignancy/Posttransplant Lymphoproliferative Disease (PTLD) serologic positivity to HIV. * Patients with evidence of urinary tract obstruction causing allograft dysfunction, unless corrected by time of enrollment. * Patients with clinical or morphological evidence of recurrence of primary disease. * Patients with a history of allergic reaction to quinolone antibiotics. * Patients with history of prolong QT interval * Patients with recurrent hypoglycemic episodes * Patients with history of myasthenia gravis * Patients taking Thioridazine