A widely used hospital antibiotic is under fresh scrutiny after a major new analysis found a possible increase in deaths among patients treated with cefepime compared with other beta-lactam antibiotics.
The finding comes from a new JAMA Network Open study published September 10. Researchers combined 110 randomized clinical trials involving 22,608 patients, making it one of the largest attempts yet to answer a safety question that has followed cefepime for nearly two decades.
The result is concerning, but it does not mean cefepime has suddenly been declared unsafe. Researchers themselves say the evidence should lead to a more careful discussion about when and how the drug is used, not its automatic removal from treatment.
What Did The New Cefepime Study Find?
Among all 110 trials, 778 of 11,726 patients who received cefepime died, compared with 674 of 10,882 patients treated with other beta-lactam antibiotics.
That works out to death rates of 6.6% with cefepime and 6.2% with the comparison drugs.
Using a Bayesian statistical model, researchers calculated a 94.4% probability that cefepime was associated with higher odds of death. The pooled odds ratio was 1.10, with a 95% credible interval from 0.98 to 1.24.
The signal became stronger when researchers looked only at 73 published, peer-reviewed trials involving 15,411 patients. In that group, cefepime was associated with a 98.6% probability of higher mortality, with an odds ratio of 1.17.
The researchers estimated a number needed to harm between 111 and 227. Put simply, if the association is truly caused by cefepime, that estimate suggests one additional death for roughly every 111 to 227 patients treated instead of another beta-lactam.
What Is Cefepime Used For?
Cefepime is a fourth-generation cephalosporin antibiotic given by injection.
It is used for serious bacterial infections including pneumonia, complicated and uncomplicated urinary tract infections, skin infections, intra-abdominal infections in combination with metronidazole, and empirical treatment of patients with febrile neutropenia.
It is particularly useful against some difficult gram-negative bacteria. The latest IDSA antibiotic guidance still describes cefepime as a preferred treatment option for certain infections involving bacteria at risk of clinically important AmpC beta-lactamase production.
That role is importnat at a time when antibiotic resistance continues to spread and doctors increasingly need drugs that remain active against resistant organisms.
Researchers Do Not Know Why The Difference Appeared
The new analysis does not prove that cefepime directly caused the additional deaths.
The authors described the result as a safety signal. One possible explanation involves dosing. Another involves cefepime neurotoxicity, particularly in older patients, critically ill patients and people whose kidneys do not clear the drug efficiently.
Neurotoxicity is not a newly discovered side effect. U.S. prescribing information already warns about serious reactions including confusion, encephalopathy, seizures and nonconvulsive status epilepticus, with kidney impairment recognized as an important risk factor.
An invited JAMA commentary published alongside the study argues that the problem may be related more to cefepime dosing than to the drug itself. Its authors wrote that cefepime remains useful and called for better prospective research into dosing and drug exposure.
The Evidence Is Not Completely One-Sided
A large randomized trial involving 2,511 hospitalized adults previously found no significant difference in acute kidney injury or death between cefepime and piperacillin-tazobactam, although patients receiving cefepime experienced more neurological dysfunction. The randomized ACORN trial results therefore add important context to the new mortality signal.
Even more recently, a September 2026 study of patients with Pseudomonas aeruginosa pneumonia reported higher mortality among patients receiving piperacillin-tazobactam rather than cefepime. The authors of that Pseudomonas pneumonia study cautioned that the sample was limited and larger studies are needed.
Different infections, doses and patient populations can produce different results. That is why a single headline cannot tell doctors which antibiotic is best for an individual patient.
Should People Taking Cefepime Be Worried?
The new study is important, but it is not a reason to stop treatment on your own.
Cefepime is generally administered in hospitals or other closely supervised medical settings for infections that can themselves become life-threatening. Choosing an alternative antibiotic also involves risks, including whether another drug will effectively treat the bacteria causing the infection.
Kidney function and dose remain particularly important because cefepime is cleared through the kidneys and excessive exposure can increase neurological toxicity.
The FDA drug safety communications do not show a new cefepime safety alert issued in response to the JAMA analysis.
Last Words
The study brings an old cefepime safety debate back into focus with substantially more trial data. It may now influence future antibiotic guidelines, dosing research and decisions about which beta-lactam is best for specific patients.
For now, the most accurate takeaway is narrower than some headlines suggest. Researchers found a possible mortality signal, particularly in adults, but they have not established that cefepime itself causes the additional deaths or that patients should stop receiving it.
