List of products in the National Drug Code with proprietary name . This medication is used to treat certain bladder/urinary tract symptoms. Flavoxate is a smooth-muscle relaxant. It works by relaxing the muscles in the bladder. Flavoxate helps to reduce leaking of urine, feelings of needing to urinate right away, frequent trips to the bathroom, and bladder pain. This medication does not treat the cause of your bladder symptoms (e.g., urinary tract/bladder/prostate infection or inflammation).