Easy bleeding/bruising, stomach upset/pain, diarrhea, and constipation may occur. If any of these effects persist or worsen, tell 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.
Although unlikely, serious bleeding in the stomach, gut, eyes, or brain may occur. Also, clopidogrel can rarely cause a very serious blood disorder (thrombotic thrombocytopenic purpura-TTP). Symptoms may appear any time after starting this medication. Get medical help right away if any of these symptoms occur: severe stomach/abdominal pain, uncontrolled bleeding from gums or nose, bloody/black stools, confusion, fever, extreme skin paleness, purple skin patches, fainting, fast heartbeat, sudden severe headache, unusual weakness/tiredness, vomit with blood or that looks like coffee grounds, slurred speech, vision changes, seizures, yellowing eyes/skin, bloody/red/pink/dark urine, change in amount of urine.
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: 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.