Methenamine helps slow the growth of bacteria. Sodium salicylate is a pain reliever and a nonsteroidal anti-inflammatory drug (NSAID) in a group of drugs called salicylates (sa-LIS-il-ates).

Methenamine and sodium salicylate is a combination medicine that is used to relieve symptoms of bladder infection or irritation, such as painful or burning urination, or feeling an urgent or more frequent need to urinate.

methenamine and sodium salicylate may help slow the progress of a bladder infection. Consult your doctor to make sure you do not need a prescription antibiotic medicine.

Methenamine and sodium salicylate may also be used for purposes not listed in this medication guide.

methenamine and sodium salicylate can increase your risk of fatal heart attack or stroke. Do not use this medicine just before or after heart bypass surgery (coronary artery bypass graft, or CABG). This medicine may also cause stomach or intestinal bleeding, which can be fatal.

Use exactly as directed on the label, or as prescribed by your doctor.

Use the lowest dose that is effective in treating your condition.

Take methenamine and sodium salicylate with a full glass of water.

Drink plenty of water each day.

Call your doctor if your symptoms do not improve after 3 days.

Store at room temperature away from moisture, heat, and light.

An NSAID can increase your risk of fatal heart attack or stroke, even if you don't have any risk factors. Do not use this medicine just before or after heart bypass surgery (coronary artery bypass graft, or CABG).

An NSAID may also cause stomach or intestinal bleeding, which can be fatal. These conditions can occur without warning while you are using methenamine and sodium salicylate, especially in older adults.

You should not use this medicine if you are allergic to methenamine, sodium salicylate, or aspirin.

Ask a doctor before using methenamine and sodium salicylate to treat painful or frequent urination if you've never had these symptoms before.

Ask a doctor or pharmacist if this medicine is safe to use if you have ever had:

• heartburn, stomach ulcers or bleeding;

• heart disease, high blood pressure;

• cirrhosis or other liver disease;

• if you are on a low-salt diet; or

• if you drink more than 3 alcoholic beverages per day.

Ask a doctor before using this medicine if you are pregnant or breastfeeding.

If you are pregnant, you should not take this medicine unless your doctor tells you to. Taking an NSAID during the last 20 weeks of pregnancy can cause serious heart or kidney problems in the unborn baby and possible complications with your pregnancy.

Do not give methenamine and sodium salicylate to a child younger than 12 without medical advice. Do not give this medicine to a child or teenager with a fever, flu symptoms, or chickenpox. Salicylates can cause Reye's syndrome, a serious and sometimes fatal condition in children.

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Ask a doctor or pharmacist before using other medicines for pain, fever, swelling, or cold/flu symptoms. They may contain ingredients similar to methenamine and sodium salicylate (such as aspirin, ibuprofen, ketoprofen, or naproxen).

Avoid alcohol. Heavy drinking can increase your risk of stomach bleeding.

Get emergency medical help if you have signs of an allergic reaction: sneezing, runny or stuffy nose; wheezing or trouble breathing; hives; swelling of your face, lips, tongue, or throat.

This medicine may cause serious side effects. Stop using this medicine and call your doctor at once if you have:

• ringing in your ears;

• a light-headed feeling, like you might pass out;

• new or worsening stomach pain; or

• bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds.

Less serious side effects may be more likely, and you may have none at all.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Ask a doctor or pharmacist before using methenamine and sodium salicylate with any other medications, especially:

• a diuretic or "water pill";

• medicine to treat gout or arthritis;

• insulin or oral diabetes medicine; or

• a blood thinner--warfarin, Coumadin, Jantoven.

This list is not complete. Other drugs may affect methenamine and sodium salicylate, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.