Cefazolin is a cephalosporin antibiotic used to treat bacterial infections. These may include infections of the respiratory tract, skin, bones, joints, genital organs, and urinary tract.
The dose and length of treatment with cefazolin depend on the infection being treated. It is given as an injection into a muscle or vein by a health care professional under medical supervision.
Cefazolin is available as a powder for injectable solution containing 1 g or 2 g of cefazolin sodium. It is available as a generic medication in the United States and should be used only with medical guidance.
What it is used for
Cefazolin is used to treat several conditions, including:
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Respiratory infections, including pneumonia;
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Skin and soft tissue infections;
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Genital infections, such as prostatitis or epididymitis;
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Biliary tract infections;
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Bacterial endocarditis, which is a type of infection that affects the heart valves;
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Urinary tract infections caused by bacteria such as Proteus mirabilis or Escherichia coli;
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Bloodstream infections;
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Bone and joint infections caused by the bacterium Staphylococcus aureus.
In addition, this antibiotic may also be used before, during, and after surgery to help prevent infections.
How to use and dosage
Cefazolin should be given as an injection directly into a vein, called intravenous use, or into a muscle, called intramuscular use, by a nurse in the hospital.
The dose depends on the infection being prevented or treated and on the doctor’s recommendation. Doses vary for adults and children, as shown below:
1. Dosage for adults
The dosage of cefazolin for adults varies depending on the condition being treated and may include:
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Acute, uncomplicated urinary tract infection: 1 g every 12 hours intravenously;
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Pneumococcal pneumonia: 500 mg every 12 hours intravenously;
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Prevention of endocarditis: 1 g intravenously, 30 minutes before surgery begins;
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Mild infections: 250 to 500 mg every 8 hours intravenously;
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Moderate to severe infections: 500 mg to 1 g every 6 to 8 hours intravenously;
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Prevention of surgical or postsurgical infections: 1 g intravenously, 30 to 60 minutes before surgery begins. For prolonged surgeries lasting 2 hours or more, 500 mg to 1 g is indicated during surgery. After surgery, the usually indicated dose is 500 mg to 1 g within the first 24 hours after surgery.
For older adults, the antibiotic dose may need to be adjusted depending on kidney function and should be calculated by the doctor. The adult dose should not exceed 6 g per day.
2. Dosage for children
The dosage of cefazolin for children older than 1 month and younger than 12 years depends on the condition being treated and may include:
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Prevention of endocarditis: 25 mg per kg of body weight intravenously, 30 minutes before surgery begins, or as directed by the pediatrician;
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Mild to moderate infection: 6.25 to 12.5 mg per kg of body weight every 6 hours, or 8.3 to 16.7 mg per kg of body weight every 8 hours, or as directed by the pediatrician;
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Severe infection: 25 mg per kg of body weight every 6 hours, or 33.3 mg per kg of body weight every 8 hours;
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Prevention of surgical or postsurgical infections in children: 25 to 30 mg per kg of body weight, or as directed by the doctor, 30 to 60 minutes before surgery begins.
For children younger than 1 month of age, the usually indicated dose is 20 mg per kg of body weight every 8 or 12 hours intravenously, or as directed by the doctor.
Possible side effects
The most common side effects of cefazolin are nausea, vomiting, diarrhea, pain at the injection site, and blisters on the skin.
Inflammation of the veins and a fungal infection in the mouth may also occur.
Cefazolin can cause severe allergic reactions or anaphylaxis, which require immediate medical care. In these cases, treatment should be stopped, especially if symptoms such as trouble breathing, cough, chest pain, swelling of the mouth, tongue, or face, or hives occur.
Who should not use it
Cefazolin should not be used by pregnant or breastfeeding women without medical guidance, or by people with colitis or kidney failure.
This antibiotic is also contraindicated in people who are allergic to cefazolin, cephalosporins, or other ingredients in the formula. The doctor should be told if the person has had even a mild allergic reaction to penicillin or other similar antibiotics.
In addition, people who take anticoagulants, such as warfarin or heparin, should tell their treating doctor before receiving cefazolin.