A third-generation cephalosporin antibiotic given by injection
Ceftazidime
An injectable antibiotic used for serious infections, including those caused by pseudomonas.
What is Ceftazidime?
Ceftazidime is a third-generation cephalosporin antibiotic given by injection or drip, used to treat serious bacterial infections in hospital. It is particularly useful because it works against a tough bacterium called pseudomonas. Like other antibiotics in its family, it can cause an allergic reaction, and people with a penicillin or cephalosporin allergy need to tell their team because of possible cross-reactivity. It can also disturb the gut bacteria and lead to a bowel infection called Clostridioides difficile (C. difficile). It is given and monitored by healthcare professionals.
Education and reference only. This is a plain-language guide to Ceftazidime — 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
Ceftazidime is an antibiotic from the cephalosporin family, specifically a third-generation cephalosporin. It is given by injection or into a vein as a drip, usually in hospital, to treat serious bacterial infections such as some chest, urine, blood and other infections. It is especially valued for being active against pseudomonas, a bacterium that is hard to treat and can cause serious infections. It is prescribed and given by healthcare professionals, who choose it when the type of infection makes it a good fit.
How it works
Ceftazidime kills bacteria by stopping them from building their cell walls, which the bacteria need to survive, so they break apart and die. Cephalosporins are broad-acting, and ceftazidime in particular reaches infections caused by a range of bacteria including pseudomonas, which many other antibiotics struggle with. Because it is given by injection or drip, it gets into the bloodstream quickly and reliably, which matters for the serious infections it is used to treat.
Company & origin
Originated / developed by: Specialist manufacturers.
A third-generation cephalosporin antibiotic given by injection, used in the UK for serious infections including those caused by pseudomonas.
Practical use
How to take Ceftazidime
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- It is given by injection or into a vein by healthcare professionals, usually in hospital, as a full course.
- Tell the team about any allergy to penicillins or cephalosporins before it is given.
- Report any new, severe or persistent diarrhoea during or after treatment, as it can signal a bowel infection.
- Complete the full course even if you feel better, to treat the infection properly.
- Report any rash, swelling, breathing difficulty or other signs of an allergic reaction straight away.
Weighing it up
Advantages & disadvantages of Ceftazidime
Advantages
- An effective antibiotic for serious infections, particularly those caused by pseudomonas.
- Given by injection or drip, so it reaches the bloodstream quickly and reliably.
- A useful option in hospital for infections that are hard to treat with other antibiotics.
Disadvantages
- Can cause allergic reactions, with possible cross-reactivity in people allergic to penicillins.
- Like other antibiotics, it can disturb gut bacteria and lead to C. difficile diarrhoea.
- Has to be given by injection or drip by professionals, rather than as a simple tablet.
Practical use
Good to know
Two safety points stand out with ceftazidime. First, it belongs to the same broad family as penicillins, so people with a penicillin or cephalosporin allergy need to tell their team, because there can be cross-reactivity and a risk of allergic reaction; a history of a severe reaction to either is especially important. Second, like many antibiotics it can upset the natural balance of bacteria in the gut and allow an overgrowth of Clostridioides difficile (C. difficile), causing diarrhoea that can become serious, so any new or severe diarrhoea during or after treatment should be reported. It is given as a course for as long as needed to treat the infection, and the team monitors the response and, where relevant, kidney function. Always finish the course as directed.
Who should not take it / use with caution
- People who have had a serious allergic reaction to ceftazidime or other cephalosporins should not be given it.
- It is used with caution in people with a penicillin allergy because of possible cross-reactivity.
- The dose is adjusted, and it is used with care, in people with reduced kidney function.
Monitoring
- Watching the response of the infection to treatment.
- Checking kidney function, especially in people whose kidneys are not working well, so the dose can be adjusted.
- Watching for allergic reactions and for any signs of C. difficile diarrhoea.
Side effects
- Diarrhoea, nausea or stomach upset.
- Reactions where the injection or drip is given, such as pain or inflammation of the vein.
- Allergic reactions, ranging from a rash to, rarely, a severe reaction.
- C. difficile diarrhoea, which can be serious and needs to be reported.
Key interactions
- Tell the team about all your medicines, including other antibiotics and medicines that affect the kidneys.
- It can affect some laboratory tests, so labs should know you are receiving it.
- Combining it with certain other medicines that affect the kidneys may need extra monitoring.
Available as: A powder made up into a solution for injection or drip into a vein or muscle.
Answers
Ceftazidime: frequently asked questions
What is ceftazidime used for?
It is an injectable cephalosporin antibiotic used for serious bacterial infections in hospital, and is particularly useful against the bacterium pseudomonas.
Can I have it if I am allergic to penicillin?
Tell your team, because cephalosporins are related to penicillins and there can be cross-reactivity; a history of a severe penicillin reaction is especially important to mention.
Why might it cause diarrhoea?
Antibiotics can upset the natural balance of gut bacteria and allow C. difficile to overgrow, causing diarrhoea that can be serious; report any new or severe diarrhoea.
Why is it given by injection rather than tablet?
Ceftazidime is given by injection or drip so it reaches the bloodstream quickly and reliably, which matters for the serious infections it treats.
Should I finish the course?
Yes; complete the full course even if you feel better, so the infection is properly treated and bacteria are less likely to come back.
The wider class
About Cephalosporin antibiotic (third-generation)
Ceftazidime belongs to the cephalosporin antibiotic (third-generation) 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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