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Cefazolin (injection)

Generic name: cefazolin (injection) [ sef-A-zoe-lin ]
Brand names: Ancef, Kefzol
Dosage forms: injectable powder for injection (1 g; 10 g; 2 g; 500 mg), injectable solution (1 g/10 mL; 2 g/100 mL-5%; 2 g/20 mL), ... show all 4 dosage forms
Drug class: First generation cephalosporins

Medically reviewed by on Jun 14, 2023. Written by Cerner Multum.

What is cefazolin?

Cefazolin is an antibiotic that is used in adults and children at least 1 month old to treat bacterial infections of the lungs, bone and joints, urinary tract, skin, genitals, and gallbladder, including those that are severe or life-threatening such as heart or blood bacterial infections.

Cefazolin is sometimes given before and after surgery to prevent infections in adults and children at least 10 years old.

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

Cefazolin side effects

Get emergency medical help if you have signs of an allergic reaction (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).

Some side effects may occur during the injection. Tell your medical caregivers if you feel dizzy, nauseated, light-headed, itchy, sweaty, or have a headache, chest tightness, back pain, trouble breathing, or swelling in your face.

Cefazolin may cause serious side effects. Call your doctor at once if you have:

Common side effects of cefazolin 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.


Tell your doctor if you use other medicines or have other medical conditions or allergies.

Before taking this medicine

Cefazolin can cause serious or life-threatening allergic reactions. You should not use cefazolin if you are allergic to cefazolin or similar medicines such as:

You may not be able to use cefazolin if you have:

Tell your doctor if you have ever had:

Tell your doctor if you are pregnant or breastfeeding.

How is cefazolin given?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Cefazolin is injected into a vein or into a muscle. A healthcare provider will give you this injection.

You may keep receiving this medicine even if your symptoms quickly improve. Skipping doses could make your infection resistant to medication. Cefazolin will not treat a viral infection (flu or a common cold).

Antibiotic medicines can cause diarrhea. Tell your doctor if you have diarrhea that is watery or bloody.

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

Follow all storage instructions provided with cefazolin. Your pharmacist can provide more information about how to store this medicine.

What happens if I miss a dose?

Call your doctor for instructions if you miss a dose of cefazolin.

What happens if I overdose?

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

An overdose can cause a seizure.

What should I avoid while receiving cefazolin?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

What other drugs will affect cefazolin?

Tell your doctor about all your other medicines, especially probenecid.

This list is not complete and many other drugs may affect cefazolin. This includes 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 this medication only for the indication prescribed.

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