A third-generation cephalosporin
Cefotaxime
A third-generation cephalosporin antibiotic given by injection in hospital for serious infections.
What is Cefotaxime?
Cefotaxime is a third-generation cephalosporin antibiotic, given by injection or drip (IV/IM) in hospital. It is used for serious bacterial infections such as meningitis, pneumonia and blood infections. People with a penicillin allergy may also react to it, and like other broad antibiotics it can occasionally trigger C. difficile diarrhoea.
Education and reference only. This is a plain-language guide to Cefotaxime — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Cefotaxime is a third-generation cephalosporin antibiotic, a relative of the penicillins. It is given by injection or drip in hospital and is used for serious infections, including meningitis, severe chest infections, and infections in the blood. It is chosen because it reaches a wide range of bacteria, including some that older antibiotics miss.
How it works
Cefotaxime works by stopping bacteria building their protective cell walls. Without an intact wall the bacteria cannot hold their shape under pressure, so they burst and die. It is active against a broad range of bacteria, which is why it is used for serious or uncertain infections while the exact cause is being identified.
Company & origin
Originated / developed by: Originally developed by Hoechst (now part of Sanofi); available as a generic medicine..
Developed in the late 1970s as one of the first third-generation cephalosporin antibiotics.
Practical use
How to take Cefotaxime
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- It is given by injection into a vein or muscle by a healthcare professional.
- The full course is completed even once you start to feel better.
- Tell the team about any allergy to penicillins or cephalosporins before it is given.
- Report any severe, watery or bloody diarrhoea promptly.
- Report any rash, swelling or breathing difficulty straight away.
- Stay well hydrated and follow the team's advice during treatment.
Weighing it up
Advantages & disadvantages of Cefotaxime
Advantages
- Works against a broad range of bacteria, useful for serious or uncertain infections.
- Penetrates well into many tissues, including the fluid around the brain, so suits meningitis.
- Long-established medicine with well-understood safety and available as a generic.
Disadvantages
- Only given by injection or drip, so it requires a hospital or clinical setting.
- Can cause cross-allergy in people allergic to penicillins.
- Like other broad antibiotics, it can disturb gut bacteria and trigger C. difficile.
Practical use
Good to know
Cefotaxime is given by a healthcare team in hospital, so dosing is managed for you. Tell staff about any previous reaction to penicillins or cephalosporins, as there can be cross-allergy. Like other broad antibiotics it can upset the natural balance of gut bacteria and occasionally lead to C. difficile infection, so report any severe or watery diarrhoea. The full course is given even if you feel better quickly.
Who should not take it / use with caution
- People who have had a serious allergic reaction to cephalosporins.
- People with a severe penicillin allergy should be assessed carefully because of cross-reactivity.
- Use is adjusted in significant kidney problems by the treating team.
Monitoring
- Whether the infection is responding to treatment.
- Kidney function, particularly in those already at risk.
- Any sign of allergic reaction or C. difficile diarrhoea.
Side effects
- Pain, redness or irritation where the injection is given.
- Diarrhoea, feeling sick or stomach upset.
- Rash or other allergic reactions.
- C. difficile-associated diarrhoea (uncommon but important).
Key interactions
- Other medicines that can affect the kidneys, used together with caution.
- Probenecid, which can raise its levels in the blood.
- It may affect the results of some blood and urine tests.
Available as: Available as a powder made up into an injection or infusion (drip).
Answers
Cefotaxime: frequently asked questions
How is cefotaxime given?
It is given by injection into a vein or a muscle by a healthcare professional, usually in hospital. It is not available as tablets.
Can I have it if I am allergic to penicillin?
Cephalosporins like cefotaxime can occasionally cause a reaction in people allergic to penicillin. Always tell the team about any previous antibiotic allergy so they can decide if it is safe.
What is C. difficile and why does it matter?
Broad antibiotics can upset the balance of gut bacteria and allow C. difficile to grow, causing severe diarrhoea. Report any severe or watery diarrhoea during or after treatment.
What is it used for?
It is used for serious bacterial infections such as meningitis, severe pneumonia and infections in the blood, often while tests identify the exact bacteria.
Do I finish the whole course?
Yes. The full course is given even if you feel better quickly, to make sure the infection is fully cleared and to reduce the risk of resistance.
The wider class
About Cephalosporins
Cefotaxime belongs to the cephalosporins class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF
- NICE CKS
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