Cephalosporin antibiotics
Cephalosporins are antibiotics that kill bacteria by stopping them from building their cell walls. They are used to treat bacterial infections such as some urinary, throat, chest, skin and ear infections. Examples include cefixime and cefuroxime. They are related to penicillins, so some people who are allergic to penicillin can also react to them.
Pharmacist review in progress. This page is based on the sources listed below and is being checked by our registered pharmacist.
How do Cephalosporin antibiotics work?
Cephalosporins attach to proteins that bacteria need to build their cell wall. Without a firm wall the bacteria burst and die. They work only on bacteria and have no effect on viruses.
Active ingredients of this type
These active ingredients belong to Cephalosporin antibiotics. They are listed A to Z.
- Cefixime: Cefixime is a third-generation cephalosporin antibiotic used to treat certain bacterial infections.
- Cefuroxime: Cefuroxime is a second-generation cephalosporin antibiotic used to treat certain bacterial infections.
Common questions
What do first, second and third generation cephalosporins mean?
The generations are groups of cephalosporins that act on somewhat different sets of bacteria. Cefuroxime is a second-generation medicine and cefixime a third-generation one. A higher generation is not automatically better; the doctor chooses the medicine that suits the infection.
Can I take a cephalosporin if I am allergic to penicillin?
Some people with penicillin allergy also react to cephalosporins, so tell your doctor about any past allergy before taking one. Get emergency help for swelling of the face, lips or throat, trouble breathing, or a fast-spreading rash after a dose.
Can cephalosporins cause diarrhoea?
Yes, loose stools are a common side effect. Rarely, antibiotics cause a serious gut infection called C. difficile, with severe or bloody diarrhoea that can start weeks after the course. See a doctor for that; do not take anti-diarrhoea medicines without advice.
Sources
- Cefixime tablets: prescribing information (Rising Pharma, revised 4/2026). DailyMed, US National Library of Medicine
- Cefuroxime axetil tablets: prescribing information (A-S Medication Solutions, revised 5/2026). DailyMed, US National Library of Medicine
- Antibiotics. NHS (UK)
- ATC/DDD Index: J01DD Third-generation cephalosporins. WHO Collaborating Centre for Drug Statistics Methodology
- ATC/DDD Index: J01DC Second-generation cephalosporins. WHO Collaborating Centre for Drug Statistics Methodology