Cephalosporins are a subclass of antibiotics called beta-lactam antibiotics (antibiotics that have a chemical structure called a beta-lactam ring). Beta-lactam antibiotics also include carbapenems, monobactams, and penicillins.
There are several classifications or generations of cephalosporins. The different generations are effective against different types of bacteria.
Most bacteria have an outer covering (cell wall) that protects them. Like the other beta-lactam antibiotics, cephalosporins work by preventing bacteria from forming this cell wall, resulting in death of the bacteria.
Because cephalosporins are structurally similar to the penicillins, some people who have an allergic reaction to penicillins may have an allergic reaction to certain cephalosporins. A health care professional can help assess the risk of allergic cross-reactivity between specific antibiotics in people who believe they have had an allergic reaction.
Cephalosporins
Medication | Common Uses | Some Potential Side Effects |
|---|---|---|
First generation | ||
Cephradine | Mainly skin and soft-tissue infections Given before surgical procedures to prevent infections Urinary tract infections | Gastrointestinal upset and diarrhea* Nausea Allergic reactions (more likely in people allergic to penicillin) |
Second generation | ||
Some respiratory infections | Gastrointestinal upset and diarrhea* Nausea Allergic reactions (more likely in people allergic to penicillin) | |
Third generation | ||
Cefditoren Cefoperazone Ceftibuten | Given by mouth: Broad coverage of many bacteria for people with mild-to-moderate infections, including skin and soft-tissue infections Given by injection: Serious infections (such as meningitis or infections acquired in a hospital) | Gastrointestinal upset and diarrhea* Nausea Allergic reactions (more likely in people allergic to penicillin) |
Fourth generation | ||
Serious infections (including Pseudomonas infections), particularly in people with a weakened immune system, and infections due to susceptible bacteria that are resistant to other antibiotics | Gastrointestinal upset and diarrhea* Nausea Allergic reactions (more likely in people allergic to penicillin) | |
Anti-MRSA cephalosporins | ||
Ceftobiprole/medocaril | Infections due to susceptible bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA) | Gastrointestinal upset and diarrhea* Nausea Allergic reactions (more likely in people allergic to penicillin) |
Other cephalosporins | ||
Urinary tract infections or pneumonia due to susceptible bacteria, such as Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, and Enterobacter, in people over 18 years of age who have limited or no alternative treatment options | Gastrointestinal upset and diarrhea* Nausea Allergic reactions (more likely in people allergic to penicillin) | |
Complicated urinary tract or abdominal infections due to sensitive organisms | Gastrointestinal upset and diarrhea* Nausea Allergic reactions (more likely in people allergic to penicillin) Kidney and liver problems | |
* Almost any antibiotic can cause Clostridioides difficile–induced diarrhea | ||
(See also Overview of Antibiotics.)
Use of Cephalosporins During Pregnancy and Breastfeeding
Cephalosporins are among the safest antibiotics to use during pregnancy but are not without risks. Each medication is slightly different and may have different side effects. (See also Safety of Medications During Pregnancy.)
Use of cephalosporins during breastfeeding is discouraged because these medications may affect the baby's digestive tract. (See also Medication and Substance Use During Breastfeeding.)
