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Generic name: cefprozilsef-PROE-zil ]
Drug class: Second generation cephalosporins

Medically reviewed by Sanjai Sinha, MD. Last updated on Apr 8, 2024.

What is Cefzil?

Cefzil is a cephalosporin (SEF a low spor in) antibiotic. It works by fighting bacteria in your body.

Cefzil is used to treat patients with mild to moderate infections caused by bacteria that are susceptible to treatment with cephalosporin antibiotics.

Cefzil may also be used for purposes not listed in this medication guide.


Cefzil should not be used in patients with a known allergy to the cephalosporin class of antibiotics.

Before taking this medicine

You should not take Cefzil if you are allergic to cefprozil or other cephalosporin antibiotics, such as:

To make sure Cefzil is safe for you, tell your doctor if you have ever had:

Cefzil liquid may contain phenylalanine. Tell your doctor if you have phenylketonuria (PKU).

Tell your doctor if you are pregnant or breastfeeding.

Some antibiotics can make birth control pills less effective. Ask your doctor about using a non-oral birth control to prevent pregnancy. This includes injections, implants, skin patches, vaginal rings, condom, diaphragm, cervical cap, or contraceptive sponge.

Cefzil is not approved for use by anyone younger than 6 months old.

How should I take Cefzil?

Take Cefzil exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medicine guides or instruction sheets.

Shake the liquid before you measure a dose. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

Cefprozil doses are based on weight in children. Follow all dosing instructions carefully when giving this medicine to a child.

Use this medicine for the full prescribed length of time, even if your symptoms quickly improve. Skipping doses can increase your risk of infection that is resistant to medication. Cefzil will not treat a viral infection such as the flu or a common cold.

Cefprozil can affect the results of certain medical tests. Tell any doctor who treats you that you are using this medicine.

Store Cefzil tablets at room temperature, away from moisture and heat.

Store Cefzil liquid in the refrigerator. Do not freeze. Throw away any unused liquid that is older than 14 days.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What to avoid

Antibiotic medicines can cause diarrhea, which may be a sign of a new infection. If you have diarrhea that is watery or bloody, call your doctor before using anti-diarrhea medicine.

Cefzil side effects

Get emergency medical help if you have signs of an allergic reaction to Cefzil (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

Call your doctor at once if you have:

Common Cefzil side effects may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Cefzil?

Tell your doctor about all your other medicines, especially:

This list is not complete. Other drugs may interact with cefprozil, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Cefzil only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.