This medication is used to relieve the discomfort, pain, frequent urge to urinate, and cramps/spasms of the urinary tract caused by an infection or a medical procedure. Methenamine is an antibiotic. Methylene blue is an antiseptic and is related to a group of drugs called monoamine oxidase inhibitors (MAO inhibitors). Both methenamine and methylene blue help to prevent the growth of bacteria in the urine. Salicylate, which is related to aspirin, is a pain reliever. This product also contains an ingredient (such as sodium phosphate, benzoic acid) to make the urine more acidic, which helps methenamine work better. Hyoscyamine is an antispasmodic drug that relaxes the muscles of the urinary tract to relieve cramps/spasms. This product should not be used to treat a urinary tract infection. If you have a bacterial infection, another antibiotic is usually prescribed to treat it. Consult your doctor for more details. This medication is not recommended for children younger than 6 years because they are more sensitive to the side effects.