Headache, nausea, and heartburn may occur. Talk with your doctor if you have a severe headache when you first start taking this medication. Your doctor may change your dose for the first week to lessen headache. If any of these effects persist or worsen, contact your doctor or pharmacist promptly.Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor immediately if any of these unlikely but serious side effects occur: easy bleeding/bruising, uncontrolled bleeding from gums or nose, fast/slow/irregular heartbeat, dark urine, yellowing eyes/skin.This drug may infrequently cause serious bleeding (especially from the stomach or intestines). If you notice any of the following rare but serious side effects, stop taking this medication and consult your doctor or pharmacist immediately: bloody/black/tarry stools, fainting, pale/bluish skin color, unusual weakness, vomit with blood or that looks like coffee grounds, persistent stomach/abdominal pain.Get medical help right away if any of these rare but serious side effects occur: symptoms of a heart attack (such as chest/jaw/left arm pain, shortness of breath, unusual sweating), signs of bleeding in the brain or stroke (such as weakness on one side of the body, slurred speech, sudden vision changes, confusion).A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: severe rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.