Cefoxitin - Intravenous

What Is Cefoxitin?

Cefoxitin is an antibiotic drug your healthcare provider may prescribe if you have certain types of bacterial infections. It is considered a broad-spectrum antibiotic because it treats a variety of bacterial infections but is only used for the types that are susceptible to its effects.

Delivered by intravenous (IV) infusion, cefoxitin belongs to a class of drugs called cephalosporin antibiotics. It works by binding to proteins that hold together the cells of the bacterial wall and, by doing so, prevents new bacteria from forming.

First approved for use by the Food and Drug Administration (FDA) in 1978, cefoxitin was sold under the brand name Mefoxin before the drug was discontinued in the United States. Cefoxitin is available by prescription only in its generic form. It may be given to adults and children 3 months and over.

It is administered via a liquid solution either by the individual at home or in a hospital setting by a healthcare professional.

Drug Facts

Generic Name: Cefoxitin

Brand Name(s): N/A; Mefoxin (discontinued)

Drug Availability: Prescription

Administration Route: Intravenous

Therapeutic Classification: Antibiotic

Available Generically: Yes

Controlled Substance: N/A

Active Ingredient: Cefoxitin sodium

Dosage Form(s): Liquid solution and powder for solution

What Is Cefoxitin Used For?

The FDA approved cefoxitin to treat specific bacterial infections. It is classified as a second-generation cephalosporin that is more active against gram-negative bacteria (bacteria with thinner walls and an outer lipid membrane) and less active against gram-positive bacteria (bacteria with thicker walls and no outer lipid membrane).

Taking the correct antibiotic reduces the risk of antibiotic resistance, which can occur when bacteria change as a result of antibiotic use, making them harder to kill.

Cefoxitin is specifically approved for the treatment of:

  • Bone and joint infections caused by Staphylococcus aureus
  • Gynecological infections, including pelvic cellulitis and pelvic inflammatory disease, caused by Escherichia coli (E. coli), Neisseria gonorrhoeae (gonorrhea), Peptococcus niger, Streptococcus agalactiae, and species of Bacteroides, Clostridium, and Peptostreptococcus
  • Inner abdominal infections, including peritonitis and intra-abdominal abscesses, that are caused by E. coli and species of Bacteroides, Clostridium, and Klebsiella
  • Lower respiratory tract infections, including pneumonia and lung abscesses, are caused by streptococci bacteria, Staphylococcus aureus, E. coli, Haemophilus influenzae, and species of Bacteroides and Klebsiella
  • Septicemia caused by Streptococcus pneumoniae, Staphylococcus aureus, E. coli, and species of Bacteroides and Klebsiella
  • Skin infections caused by streptococci bacteria, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, E. coli, Proteus mirabilis, Peptococcus niger, and species of Bacteroides, Clostridium, Klebsiella, and Peptostreptococcus
  • Urinary tract infections caused by E. coli, Proteus mirabilis, Morganella morganii, Proteus vulgaris, and species of Providencia and Klebsiella

Cefoxitin is also used in prophylactic therapy to prevent postoperative bacterial infections in people who are undergoing gastrointestinal surgery, vaginal or abdominal hysterectomy, or cesarean section (C-section).

How to Take Cefoxitin

You may receive a cefoxitin injection in a hospital or you may administer the medication at home. If you will be receiving cefoxitin injection at home, your healthcare provider will show you how to use the medication. Be sure that you understand these directions, and ask your healthcare provider if you have any questions.

Depending on the type and severity of infection you have, the dose can range from 1 to 3 grams per infusion. The course of treatment may involve anywhere from three to eight infusions, with each infusion separated by four to eight hours. Each infusion takes around 30 minutes to complete.


If administering at home, keep cefoxitin at room temperature, away from direct heat, moisture, and light. Do not store in a bathroom. Finally, keep the medication out of reach of children and pets.

Off-Label Uses

Cefoxitin is sometimes used off-label with the antibiotic drug Flagyl (metronidazole) to treat skin infections caused by animal bites. It can also be used as part of a multidrug regimen to treat mycobacterial lung infections not related to tuberculosis, the most common form of mycobacterial infection.

Cefoxitin is sometimes used off-label to defend against infection in newborns who are 1 to 2 months of age. It is used in infants with caution and when the benefits should outweigh the risks.

How Long Does Cefoxitin Take to Work?

Cefoxitin begins working within five minutes of IV injection. However, the presence of Cefoxitin in the bloodstream begins to fade around four hours after injection.

What Are the Side Effects of Cefoxitin?

The following is not a complete list of side effects and others may occur. A medical professional can advise you on side effects. If you experience other effects, contact your pharmacist or a medical professional. You may report side effects to the FDA at www.fda.gov/medwatch or 800-FDA-1088.

As with all medications, cefoxitin can cause side effects. Tell your healthcare provider about any side effects you experience while taking this medication.

Common Side Effects

Cefoxitin is generally well tolerated and causes infrequent side effects. By far the most common is thrombophlebitis, an inflammatory reaction that causes the formation of a blood clot in a vein (usually superficial and non-severe).

Less commonly, cefoxitin has been known to cause rash, diarrhea, and symptoms of low blood pressure in some people, which include dizziness, nausea, blurred vision, and clammy skin.

Severe Side Effects

On rare occasions, cefoxitin use has triggered potentially severe allergic reactions, including:

Anaphylaxis, a potentially life-threatening whole-body allergic reaction, is a concern with all antibiotics. Even so, the risk is extremely low with intravenous cephalosporins, the class of antibiotics that cefoxitin is in. Anaphylaxis affects about 7 of every 100,000 users. The risk of death is even lower, running at around 0.001%.

Between 1% and 3% of the population is thought to have some form of cephalosporin allergy, ranging from mild to severe.

Call your healthcare provider right away if you have serious side effects while taking cefoxitin. Call 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency. These include symptoms of anaphylaxis, such as:

If not treated immediately, anaphylaxis can lead to shock, coma, cardiac or respiratory arrest, and death.

Long-Term Side Effects

Cefoxitin is intended for the short-term treatment of an acute bacterial infection. The prolonged use of cefoxitin can affect the balance of microorganisms in the digestive tract and other parts of the body, leading to the overgrowth of fungus or non-susceptible bacteria.

This can lead to something called a superinfection, in which an infection occurs after or on top of an earlier infection. Superinfection is commonly associated with the overuse of broad-spectrum antibiotics.

Report Side Effects

Cefoxitin may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).

Dosage: How Much Cefoxitin Should I Take?

A healthcare provider will determine the dosage and administer this medication to you.


Cefoxitin is excreted from the body in urine. People with kidney problems require a dose adjustment because the kidneys are less able to filter the drug from the bloodstream. The adjustment helps prevent the toxic accumulation of the drug.

The dose is based on the level of kidney impairment as measured by a creatinine clearance (CrCl) test. This is a test that measures the speed at which a waste product called creatinine is excreted in the urine, described in milliliters per minute (mL/min).

People with any level of kidney dysfunction would be given a loading (starting) dose of between 1 and 2 grams. The subsequent doses would then be prescribed as follows:

  • Mild kidney impairment (30–50 milliliter/minute): 1–2 grams every eight to 12 hours
  • Moderate kidney impairment (10–29 milliliter/minute): 1–2 grams every 12–24 hours
  • Severe kidney impairment (5–9 milliliter/minute): 0.5 to 1 g every 12–24 hours
  • Essentially no kidney function (under 5 milliliter/minute): 0.5–1 gram every 24–48 hours

Prophylactic dosage:

When used as prophylactic therapy for gastrointestinal (GI) surgery, vaginal or abdominal hysterectomy, or C-section, the recommended dosage is as follows:

  • Initial dose: 2 grams delivered 30 minutes to one hour before surgery
  • Subsequent doses: 2 grams delivered every six hours after the first dose for no more than 24 hours

Users should also be aware of the following before beginning cefoxitin:

Pregnancy: ​​Cefoxitin is relatively safe for use during pregnancy. Classified as a Pregnancy Category B drug, cefoxitin has been studied extensively in rats, with no evidence of birth defects, miscarriage, or stillbirth when dosed at 7.5 times the recommended dose in humans. Pregnancy registries have not shown an increased risk of adverse effects in pregnant humans compared to the general population.

Breastfeeding: Cefoxitin is excreted in breast milk. Although there is no evidence that this poses any harm to a nursing baby, speak with your healthcare provider to fully weigh the risks and benefits of treatment if you are pregnant, become pregnant, are trying to become pregnant, or are breastfeeding.

Adults over 65: In older, disabled, or potentially malnourished people, or in individuals with renal (kidney) or hepatic (liver) issues, the initial dosing, dose increments, and maintenance dosage should be closely monitored to assure healthy renal function as this drug is known to be substantially filtered by the kidney.

Pediatric use: The safety and effectiveness of cefoxitin have not been established in children under three months of age. Cefoxitin is prescribed for use only in people who require the entire 1- or 2-gram dose.

People who smoke: Smoking can lower cefoxitin's effectiveness. Try to stop smoking before starting cefoxitin, and avoid smoking while taking cefoxitin. Your healthcare provider can help you with this goal.

Missed Dose

If administering at home, take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not use a double dose to make up for a missed one.

Overdose: What Happens If I Take Too Much Cefoxitin?

Because cefoxitin is often administered by a medical professional, the risk of an overdose is low. If one were to occur, it can have toxic effects on the brain and cause seizures and other symptoms of encephalopathy (a condition causing brain dysfunction). Nausea, vomiting, diarrhea, stomach pain, and blood in urine can also occur.

A cefoxitin overdose is treated symptomatically with IV fluids, antidiarrheals, anti-nausea drugs, and anticonvulsants like benzodiazepines if needed.

Common symptoms of a potential medication-related overdose include:

What Happens If I Overdose on Cefoxitin?

If you think you or someone else may have overdosed on cefoxitin, call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses or isn't breathing after taking cefoxitin, call 911 immediately.


Drug Content Provided and Reviewed by IBM Micromedex®

If your symptoms or your child's symptoms do not improve within a few days, or if they become worse, check with your doctor.

Cefoxitin injection may cause diarrhea, and in some cases it can be severe. Do not take any medicine or give medicine to your child to treat diarrhea without first checking with your doctor. Diarrhea medicines may make the diarrhea worse or make it last longer. If you have any questions about this or if mild diarrhea continues or gets worse, check with your doctor.

Before you or your child have any medical tests, tell the medical doctor in charge that you are receiving this medicine. The results of some tests may be affected by this medicine.

What Are Reasons I Shouldn't Take Cefoxitin?

Cefoxitin should never be given to anyone with a known hypersensitivity to cefoxitin sodium or any other beta-lactam antibiotic. This includes cephalosporins, penicillins, carbapenems, monobactams, and beta-lactamase (the overarching category of enzymes involved in bacterial resistance) inhibitors.

Cefoxitin should only be used to treat infections that are proven to be (or strongly believed to be) caused by susceptible bacteria. This may require tests by a pathologist to positively identify the type and species of bacteria involved. Treating non-susceptible bacteria with cefoxitin can increase the risk of antibiotic resistance.

What Other Medications May Interact With Cefoxitin?

Tell your healthcare provider about all of the medicines you take, including prescription and over-the-counter (OTC) medicines, and vitamins or supplements. 

There are few drug interactions associated with cefoxitin. However, the concurrent use of cefoxitin with another class of antibiotics known as aminoglycosides can be toxic to the kidneys and impair kidney function. Severe cases may lead to acute kidney failure.

The aminoglycosides that pose the greatest potential risk include:

To avoid interactions, always advise your healthcare provider about any medications you take, whether they are prescription, OTC, nutritional, herbal, or recreational.

What Medications Are Similar?

Cefoxitin is a second-generation cephalosporin that is most effective in treating gram-negative bacterial infections.

The other three drugs in this group of antibiotics are:

Some of these drugs are more effective in treating certain bacterial infections than others. For instance, cefoxitin, Cefotan (cefotetan), and cefprozil are better able to kill Bacteroides species, while cefuroxime is the preferred option for treating Haemophilus influenzae infections.

While newer third- and fourth-generation cephalosporins are able to treat a broader range of gram-negative bacteria, second-generation cephalosporins are still considered the drug of choice for treating certain bacterial infections.

Frequently Asked Questions

  • What is cefoxitin used for?

    Cefoxitin is a broad-spectrum antibiotic used to treat specific severe bacterial infections. It belongs to a class of drugs called cephalosporins that are effective against gram-negative bacteria such as E. coli and Staphylococcus aureus. The drugs are delivered by IV infusion in a hospital setting.

  • How does cefoxitan work?

    Cefoxitin works by binding to proteins called transpeptidases that connect the molecules that make up the cellular wall of bacteria. By doing so, it prevents the proper formation of new bacteria, leading to rapid death. Cefoxitin is more active against gram-negative bacteria in part because they have thinner walls than gram-positive bacteria.

  • What are the side effects of cefoxitin?

    Cefoxitin is generally well tolerated but can cause superficial blood clots at the injection site, known as thrombophlebitis. Less commonly, it causes diarrhea, low blood pressure, and rash (usually mild).

How Can I Stay Healthy While Taking Cefoxitin?

If cefoxitin is prescribed, it is generally because you have a serious bacterial infection that is better treated with an intravenous antibiotic than an oral one.

While the hospital staff will oversee your treatment (as well as ensure nutrition, hydration, and the management of side effects), you can do your part by advising the staff about any medications you take and any side effects you have experienced in the past.

If you are going to be hospitalized overnight, bring your medications with you and let the hospital staff dispense them along with any other drugs you may be prescribed.

The more that the hospital staff knows about your treatment history, the better able they will be to respond if an adverse reaction occurs.

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended to replace medical advice, diagnosis, or treatment from a healthcare provider. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.

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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By James Myhre & Dennis Sifris, MD
Dennis Sifris, MD, is an HIV specialist and Medical Director of LifeSense Disease Management. James Myhre is an American journalist and HIV educator.