1 What Is Ancef?

Brand: Ancef

Generic: Cefazolin

Brand: Ancef

Generic: Cefazolin

Cefazolin is the prototype first-generation cephalosporin that is active against Streptococci (pyogenes as well as viridans), gonococci, meningococci, C. diphtheriae, H. influenzae, clostridia, and Actinomyces. Activity against Klebsiella, Moraxella catarrhalis, and E. coli is relatively high, but it is quite susceptible to staphylococcal β-lactamase.

Cefazolin causes bacterial cell wall lysis, which is the basis of bactericidal activity for susceptible bacteria. It can be given intramuscularly (less painful) as well as intravenously and has a longer half-life (two hours) due to slower tubular secretion. It also attains higher concentration in plasma and bile. In addition, it is the preferred parenteral first-generation cephalosporin, especially for surgical prophylaxis.

This drug is available only with a doctor's prescription, and you can get it in the form of a powder or solution.

Cefazolin is used to treat a wide variety of bacterial infections. It is also used to prevent infection before and during surgeries. Cefazolin is also known as cyclosporine antibiotic. It inhibits the growth of bacteria. Cefazolin is marketed under the brand name Ancef. Bacteria that causes infection of the skin, lungs, joints, blood, stomach, heart valve, and urinary tract are targeted by this drug. In 1973, cefazolin was approved by the FDA. Today, many companies are manufacturing this drug. 

Cefazolin attacks the cell wall of the bacteria, thus preventing the synthesis of a substance called peptidoglycan. This substance gives the cell wall its strength and helps the bacteria survive inside the human body.

Specifically, cefazolin is used to treat conditions such as:

  • Cellulites
  • Pneumonia
  • Biliary tract infections
  • Endocardiatis
  • Urinary tract infections
  • Joint infections
  • Around the time of delivery, it is used to prevent group streptococcal disease.

In 1971, cefazolin was patented and made commercially available. It is an effective and safe medicine available in a generic form. A wide variety of infections are treated using this drug. Cefazolin cannot be used to treat meningitis since it does not penetrate into the central nervous system. It is not effective against methicillin-resistant staphylococcus aureus, but it is effective against methicillin-susceptible staphylococcus aureus. In cases of bacteremia, cefazolin is used as an alternative to penicillin for people who are allergic to penicillin. However, these patients could be allergic to cefazolin, too. Some species of bacteria, such as Chlamydia and mycoplasma, are resistant to this drug. Cefazolin is not effective against enterococcus, atypical bacteria, or anaerobic bacteria.


This medicine is used against infections caused by susceptible bacteria, such as:

  • Biliary tract infections: It is used to treat infections caused by Escherichia coli, proteus mirabilis, and various strains of streptococci, Klebsiella sp., and staphylococcus.
  • Bone and joint infections: This medication is used to treat infections caused by staphylococcus aureus.
  • Genital infections: Such as prostatitis epididymis caused by E. coli and Proteus mirabilis, Klebsiella sp., and enterococci sp.
  • Respiratory tract infections: This medication is useful against streptococci pneumonia, staphylococcus aureus, staphylococcus pyogenes and beta-hemolytic streptococci, Klebsiella sp., and haemophilus influenza.
  • Skin/skin structure infections: This medicine is effective against infections caused by staphylococcus aureus, staphylococcus pyogenes, beta-hemolytic streptococci, and staphylococcus agalactiae and streptococci strains.

Its use is recommended in the case of:

  • Open procedures on the biliary tract
  • Appendectomy-uncomplicated procedures
  • Coronary artery bypass or insertion procedures of cardiac devices, such as a pacemaker or implantation
  • Cesarean delivery
  • Procedures involving entry with or without entry into the GI tract
  • Clean contaminated cancer procedures
  • Heart/lung transplantation
  • Hernia repair
  • Neurosurgery
  • Hysterectomy
  • Intrathecal pump implantation
  • Hip fracture repair internal fixation device implantation or total joint replacement
  • Plastic surgery
  • Small intestine procedures
  • Non-cardiac thoracic procedures
  • Clean procedures with or without entry into the urinary tract
  • Vascular procedures

2 What To Know Before Using

If you are about to start a drug therapy, the risk-benefit ratio of taking this drug should be considered carefully. The suitable drug therapy is chosen with the active participation of both the doctor and patient.

Sometimes, cefazolin is used in patients with heart conditions, patients having dental or upper respiratory tract procedures, or who are allergic to penicillin. They are given cefazolin in order to prevent heart valve infections.

Important factors such as drug interactions, metabolic impairment, hypersensitivity reaction, pregnancy, and lactation may alter the desired, therapeutic effects of the medication.

Sometimes, the presence of other health disorders affects the beneficial effects of this medicine and may even cause serious toxic effects. If you have had any allergic reactions to any medicine, you must inform your doctor.

You should not use this drug if you have any of the following health disorders:

  • Known hypersensitivity to cefazolin or other cephalosporins
  • Stomach or bowel disease (e.g., colitis or severe diarrhea)
  • Moderate to severe liver disease (e.g., liver cirrhosis)
  • Certain kidney disorders (e.g., acute renal failure)
  • Undernourished condition
  • Seizures

If you have any allergies to medicines, foods, preservatives, or dyes, inform your doctor.

Cefazolin used along with Coumadin is known to cause easy bleeding. It is necessary to test the prothrombin time, or international normalized ratio. Moreover, the doctor needs to adjust the dose. If you experience any other problems, such as unusual bleeding or bruising, blood in the urine or stool, vomiting, dizziness, weakness, or headache, inform your doctor. A total of forty-two drugs have been known to interact with cefazolin; one interaction is major, thirty-eight are moderate, and three are minor.

Moreover, certain drugs should not be used concurrently with this medication. It is always recommended to consult your doctor if you are in need of other medications or even any over-the-counter medicines for another health problem in order to avoid unwanted toxic effects. In addition, you should know that concurrent use of probenecid prolongs the duration of action of cefazolin by decreasing its renal tubular secretion.

This medicine is not recommended for newborn or premature babies, since it is found to be toxic. To date, appropriate studies have not shown pediatric-specific or geriatric-specific problems that would limit the usefulness of this medicine. Generally, elderly people who have kidney disease or any other age-related problem have to have the dosage adjusted accordingly.

Studies performed with cefazolin in pregnant and lactating women have failed to demonstrate a risk to the fetus or nursing baby, respectively. Thus, this medicine can be used during pregnancy and lactation if clearly needed.

As per AHA guidelines, endocarditis prophylaxis recommends cefazolin only for patients at high risk. In severe renal insufficiency, the dose must be adjusted. Prolonged use may cause:

  • Hepatic or renal disease
  • Nutritional deficiency
  • Increased normalized ratio
  • Super infection of fungi or bacteria 

Patients with seizures and renal impairment should use this drug with caution.

3 Proper Usage

Currently, cefazolin is one of the most commonly used antibiotics. It covers a wide range of gram-positive and gram-negative bacteria, including some anaerobes, but not B. fragilis, enterococci, mycobacteria, or chlamydia.

This medicine is intended for intravenous use only. It should be given to patients by a nurse or other trained health professional in a hospital. The therapeutic dose and the duration of the drug therapy may vary with the severity of the patient’s condition.

It also comes in the form of a powder. This should be mixed with a liquid. In powder form, if you are using the medicine at home, follow the instructions about how to mix and store the medicine properly. Before measuring a dose, shake the medicine.

The injectable form should be given through an IV, inserted into a muscle or vein. Do not self-inject. Injections can be done at home, too. You will be shown how to use the injection at home. Dispose of the needles, IV tubing, syringes, and other materials used. Use a puncture-proof sharp disposal container.

The medicine can also come as a premixed product that should be injected intravenously over a period of thirty minutes.

Symptoms may improve after using the medicine, before the infection is cleared. But do not stop the medicine; use it as prescribed. If you miss or skip a dose, it may increase the risk of infection. Viral infections cannot be treated with cefazolin. Certain lab tests, such as a urine test for glucose, may be altered due to the use of this medicine, so inform the doctor or nurse beforehand.


0.5g eight hourly (mild cases); 1g six hourly (severe cases); 25-50mg/kg/day i.m. or i.v. (children); 1.0g as surgical prophylaxis (one or two hours before surgery).

If you miss a dose of this medicine, take it as soon as possible. However, if it is time for your next dose, skip the missed dose and go back to your regular treatment schedule.

Furthermore, it is advised to store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. All kinds of medicines should be kept out of the reach of children, and outdated medicines should be disposed of appropriately.

4 Precautions To Take

Regular visits to your doctor are recommended to check that the medicine is working properly.

Additionally, the following guidelines should be followed while you are using such medications:

  • Cefazolin should be used with extreme care in elderly patients associated with/without renal dysfunction and/or a recent history of seizures.
  • Close monitoring of patients undergoing cefazolin therapy is recommended to watch for hypersensitivity reactions, superinfection development, drug resistance, and other adverse reactions.
  • This drug therapy may cause a fall in prothrombin activity. Thus, monitoring of prothrombin time (PT) in patients previously stabilized on anticoagulant therapy (e.g., warfarin) should be carried out. However, exogenous vitamin K should be given to such patients to prevent further complications.
  • Cefazolin has been implicated in triggering seizures, particularly in patients with renal impairment. If seizures occur during this therapy, the drug should be stopped right away. Further, anticonvulsant therapy can be given if clinically indicated.
  • About 10% of patients allergic to penicillin show cross reactivity with cephalosporins. Those with a history of immediate reactions to penicillin should not be treated with cefazolin.
  • Before you undergo any medical tests, you should inform your doctor that you are using this medicine, as the results of some tests may be affected by cefazolin.

5 Potential Side Effects

There are some unwanted side effects associated with each drug that usually do not need medical attention. These side effects generally go away during treatment as the body adjusts to the medicine.

In addition, your doctor may advise you on how to prevent or reduce those unwanted side-effects.

You may need to consult a doctor if the following problems become significant:

  • Pain at the injection site is a common adverse effect when cefazolin is injected intramuscularly. Thrombophlebitis may also occur in some individuals in the case of intravenous administration.
  • Nausea, vomiting, anorexia, diarrhea, stomach cramps, and pseudomembranousHYPERLINK "" colitis have been reported due to alteration of gut ecology or irritative effects, but this is rare.
  • Hypersensitivity reactions are the most significant adverse effects of cefazolin, but such incidences are low. Rashes are the most frequent manifestation, but anaphylaxis, angioedema, asthma, and urticaria have also occurred.
  • Cefazolin has low-grade nephrotoxicity, which may be accentuated by preexisting renal disease, concurrent administration of an aminoglycoside, or a loop diuretic.
  • Bleeding occurs due to hypoprothrombinemia, and this incidence is more common in patients with cancer, intra-abdominal infection, or renal failure.
  • Neutropenia and thrombocytopenia are rare adverse effects.
  • Reports of hepatitis, oral candidiasis (oral thrush), and genital and anal pruritus (including genital moniliasis, vulvar pruritus, and vaginitis) have been received.

Rare side effects include:

  • Changes in skin color
  • Swelling of the foot or leg
  • Tenderness
  • Pain
  • Bluish color

Some side effects may be so minor that medical attention is not be needed. Slowly, these side effects go away as the body adjusts to the medication. However, if these side effects persist, check with your doctor. 

Cefazolin injections may cause the following side effects:

  • General itching
  • Loss of appetite
  • Gas or heart burn
  • White patches in the mouth
  • Confusion
  • Weakness and tiredness

Cefazolin injections may also cause serious side effects that need medical attention. These include:

  • Hives and itching
  • Watery or bloody stools
  • Fever during treatment or two to three months after stopping treatment
  • Difficulty breathing or swallowing
  • Swelling in the legs or feet
  • Shedding of skin, or bleeding or peeling of skin
  • Dark urine and decreased urination
  • Pain in the upper right portion of the stomach
  • Fainting
  • Sore throat, fever, or any other signs of infection
  • Mental or mood changes
  • Pounding or irregular heart beat
  • Yellowing of the eyes
  • Rarely, cefazolin may cause clostridium difficile-associated diarrhea, which is a severe intestinal condition. It occurs due to resistant bacteria. Anti-diarrheal products make the condition worse, so do not use narcotic anti-diarrheal medications.

This drug is metabolized minimally by the liver and is excreted in the urine. Its half-life is ninety to one hundred and fifty minutes. Its capacity to cross the blood-brain barrier is poor, and it is active against the skin flora, particularly against staphylococcus aureus.

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