Clopidogrel has been evaluated for safety in more than 17,500 patients, including over 9,000 patients treated for 1 year or more. The overall tolerability of clopidogrel was similar to that of aspirin regardless of age, gender and race. The most common adverse effects were gastrointestinal hemorrhage, gastrointestinal events like abdominal pain, dyspepsia, gastritis, constipation and diarrhea. Other adverse effects occurring in 1% to 2.5% of patients receiving clopidogrel are rash and skin disorders, syncope, palpitation, asthenia, hernia, cramps in legs, hypoaesthesia, neuralgia, paraesthesia, vertigo, arthritis, arthrosis, anxiety, insomnia, anemia, hemorrhagic gastritis, hemorrhagic upper GI ulcer, bilirubinemia, infectious hepatitis, and fatty liver.