Omnicef is in a group of drugs called cephalosporin antibiotics. It works by fighting bacteria in your body. Omnicef is used to treat many different types of infections caused by bacteria, such as acute flare-ups of chronic bronchitis, middle ear infections, throat and tonsil infections, pneumonia, sinus infections and skin infections. Omnicef may also be used for other purposes not listed in this medication guide.

The health and medical information provided here is for general purposes only and is not a substitute for the expertise and judgment of your physician, or other health care professional. It should not be understood to indicate that the use of this medicine is safe, appropriate or effective for you. Always consult your health care professional before using this, or any other, drug.

Do not take Omnicef if you are allergic to cefdinir, or to similar antibiotics, such as Ceftin, Cefzil, Keflex, and others.
Before taking this medication, tell your doctor if you are allergic to any drugs (especially penicillin). Also tell your doctor if you have kidney disease or a history of intestinal problems.
Take this medication for the entire length of time prescribed by your doctor. Your symptoms may get better before the infection is completely treated. Omnicef will not treat a viral infection such as the common cold or flu.
Antibiotic medicines can cause diarrhea, which may be a sign of a new infection. If you have diarrhea that is watery or has blood in it, call your doctor. Do not use any medicine to stop the diarrhea unless your doctor has told you to.

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Call your doctor at once if you have any of these serious side effects:
diarrhea that is watery or bloody;
chest pain;
fever, chills, body aches, flu symptoms;
unusual bleeding;
seizure (convulsions);
pale or yellowed skin, dark colored urine, fever, confusion or weakness;
jaundice (yellowing of the skin or eyes);
fever, sore throat, and headache with a severe blistering, peeling, and red skin rash; or
increased thirst, loss of appetite, swelling, weight gain, feeling short of breath, urinating less than usual or not at all.
Less serious Omnicef side effects may include:
constipation, loss of appetite, bloating, gas, upset stomach;
nausea, vomiting, stomach pain, mild diarrhea;
headache, dizziness;
stiff or tight muscles;
feeling restless or hyperactive;
dry mouth;
unusual or unpleasant taste in your mouth;
diaper rash in an infant taking liquid Omnicef;
mild itching or skin rash; or
vaginal itching or discharge.

Take Omnicef exactly as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor. Follow the directions on your prescription label.
You may take this medication with or without food.
Shake the oral suspension (liquid) well just before you measure a dose. To be sure you get the correct dose, measure the liquid with a marked measuring spoon or medicine cup, not with a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist for one.
This medication can cause you to have false results with certain medical tests, including urine glucose (sugar) tests. Tell any doctor who treats you that you are using Omnicef.
Take Omnicef for the entire length of time prescribed by your doctor. Your symptoms may get better before the infection is completely treated. Omnicef will not treat a viral infection such as the common cold or flu. Store the capsules at room temperature away from moisture, heat, and light. Store Omnicef oral liquid in the refrigerator. Do not allow it to freeze. Throw away any unused medication that is older than 14 days.