Nabumetone is a nonsteroidal anti-inflammatory drug (NSAID). Nabumetone works by reducing hormones that cause inflammation and pain in the body.

Nabumetone is used to relieve the symptoms of rheumatoid arthritis or osteoarthritis.

Nabumetone may also be used for purposes not listed in this medication guide.

Nabumetone 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).

Nabumetone may also cause stomach or intestinal bleeding, which can be fatal. These conditions can occur without warning while you are using nabumetone, especially in older adults.

You should not use nabumetone if you are allergic to it, or if you have ever had an asthma attack or severe allergic reaction after taking aspirin or an NSAID.

Tell your doctor if you have ever had:

• heart disease, high blood pressure, high cholesterol, diabetes, or if you smoke;
• a heart attack, stroke, or blood clot;
• stomach ulcers or bleeding;
• asthma;
• liver or kidney disease; or
• fluid retention.

If you are pregnant, you should not take nabumetone 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.

You should not breastfeed while using this medicine.

Nabumetone is not approved for use by anyone younger than 18 years old.

Use Relafen DS (Oral) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Get emergency medical help if you have signs of an allergic reaction (hives, sneezing, runny or stuffy nose, wheezing, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

Get emergency medical help if you have signs of a heart attack or stroke: chest pain spreading to your jaw or shoulder, sudden numbness or weakness on one side of the body, slurred speech, feeling short of breath.

Stop using nabumetone and call your doctor at once if you have:

• shortness of breath (even with mild exertion);
• swelling or rapid weight gain;
• the first sign of any skin rash, no matter how mild;
• signs of stomach bleeding--bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds;
• liver problems--nausea, upper stomach pain, itching, tired feeling, flu-like symptoms, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);
• kidney problems--little or no urinating, painful or difficult urination, swelling in your feet or ankles, feeling tired or short of breath; or
• low red blood cells (anemia)--pale skin, unusual tiredness, feeling light-headed or short of breath, cold hands and feet.

Common side effects may include:

• stomach pain, indigestion, nausea;
• diarrhea, constipation, gas;
• swelling in your hands and feet;
• headache, dizziness;
• itching, skin rash; or
• ringing in your ears.

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.

Avoid drinking alcohol. It may increase your risk of stomach bleeding.

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

Nabumetone could make you sunburn more easily. Avoid sunlight or tanning beds. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.