Inclusion Criteria

DISEASE CHARACTERISTICS: Stage Ta (any grade) transitional cell carcinoma of the bladder
on basis of cystoscopy Recurrent disease no greater than T1 Must not be at high risk for
upper tract (ureter or renal pelvic) transitional cell cancers

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: SWOG 0-2 Life expectancy:
Not specified Hematopoietic: Not specified Hepatic: Not specified Renal: Not specified
Other: Not pregnant or nursing Fertile patients must use effective contraception No other
prior malignancy in the past 5 years except adequately treated basal cell or squamous cell
skin cancer, carcinoma in situ of the cervix, or adequately treated stage I or II cancer
in complete remission No allergies to fluoroquinolones If allergic to penicillin or
cephalosporin, must be able to take co-trimoxazole

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: At least 28 days
since prior intravesical therapy and recovered Endocrine therapy: Not specified
Radiotherapy: At least 28 days since prior radiotherapy and recovered Surgery: Not
specified Other: At least 3 months prior to cystoscopy since prior fluoroquinolones No
concurrent fluoroquinolones No concurrent hemodialysis or peritoneal dialysis No
concurrent probenecid or theophylline No concurrent antacids containing aluminum,
magnesium or calcium, products containing iron or zinc, caffeine, cyclosporine, or
warfarin