Side effects of Cefdinir Capsules include gastrointestinal discomfort, allergic reactions, hematologic abnormalities, and vitamin deficiency symptoms. 1. Gastrointestinal discomfort: such as abdominal pain, diarrhea, stomach upset, loss of appetite, nausea, vomiting, heartburn, constipation. 2. Allergic reactions: e.g. rash, urticaria, itching, fever, edema, erythema, etc. 3. Hematological abnormalities: e.g. eosinophilia, neutropenia, etc. 4. Vitamin deficiency symptoms: such as bleeding tendency and other vitamin K deficiency, as well as lingual inflammation, stomatitis, neuritis and other vitamin B complex deficiency symptoms. 5. Others: such as headache, vertigo, chest pressure, numbness and so on. Patients taking Cefdinir Capsules, if any of the above discomfort occurs, the drug should be stopped immediately, and promptly seek medical attention, under the guidance of the doctor for appropriate treatment.