In Each Tablet: Other Information: This product may stain contact lenses. This product can interfere with laboratory tests including urine glucose (sugar), and ketones test. Long term administration of phenazopyridine hydrochloride has induced neoplasia in rats (large intestine) and mice (liver). Although no association between phenazopyridine hydrochloride and human neoplasia has been reported, adequate epidemiological studies along these lines have not been conducted. Store at 20 degrees - 25 degrees C (68 degrees - 77 degrees F) in a dry place and protect from light.