Side effects

Upset stomach, nausea, vomiting, heartburn, headache, diarrhea, constipation, drowsiness, and dizziness may occur. If any of these effects persist or worsen, notify your doctor or pharmacist promptly. Tell your doctor immediately if any of these serious side effects occur: stomach pain, swelling of the hands or feet, sudden or unexplained weight gain, ringing in the ears (tinnitus). Tell your doctor immediately if any of these unlikely but serious side effects occur: vision changes, rapid or pounding heartbeat, easy bruising or bleeding. Tell your doctor immediately if any of these highly unlikely but very serious side effects occur: change in amount of urine, severe headache, very stiff neck, mental/mood changes, persistent sore throat or fever. This drug may infrequently cause serious (rarely fatal) bleeding from the stomach or intestines. If you notice any of the following unlikely but very serious side effects, stop taking naproxen and consult your doctor or pharmacist immediately: black stools, persistent stomach/abdominal pain, vomit that looks like coffee grounds. This drug may rarely cause serious (possibly fatal) liver disease. If you notice any of the following highly unlikely but very serious side effects, stop taking naproxen and consult your doctor or pharmacist immediately: yellowing eyes and skin, dark urine, unusual/extreme tiredness. An allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of an allergic reaction include: rash, itching, swelling, severe dizziness, trouble breathing. If you notice other effects not listed above, contact your doctor or pharmacist.