A commonly used antibiotic has been associated with a higher risk of death in a major new analysis. Cefepime is used against bacterial infections including pneumonia, urinary tract infections and skin infections, and healthcare providers typically administer it by injection in clinical settings.

The medication can cause severe side effects, according to Mayo Clinic. These may include confusion, decreased consciousness or seizures, particularly among older patients and people with kidney problems, along with numerous more common symptoms.

The global study, published in JAMA Network Open, reviewed 110 randomized clinical trials involving more than 22,000 patients. Participants received either cefepime or another beta-lactam antibiotic, a drug class that includes penicillins and cephalosporins.

The trials included adults and children who were treated for several serious medical conditions. These included pneumonia, urinary tract infections, meningitis, severe bacterial infections and febrile neutropenia, a medical emergency involving fever and dangerously low levels of white blood cells that fight infection.

Across the trials, 778 deaths occurred among 11,726 patients who received cefepime, representing 6.6% of that group. Among patients who received another antibiotic, the mortality rate was 6.2%.

Researchers evaluated deaths from any cause that occurred within about 30 days of treatment. Using a Bayesian meta analysis, they calculated a 94.4% probability that cefepime was associated with higher all cause mortality than other beta-lactam antibiotics.

The probability became even greater when researchers narrowed the analysis to 73 published trials that had undergone peer review. Within that group of trials, the probability increased to 98.6%.

The association appeared stronger among adults than among children. It was most pronounced among patients receiving cefepime for febrile neutropenia, although that condition itself carries a substantial risk of death.

Cefepime remains a commonly used broad spectrum antibiotic for serious bacterial infections among hospitalized patients. Clinicians use the medication because it is effective against a wide range of bacteria.

Despite the findings, researchers did not recommend that clinicians stop using cefepime. Instead, they called for further research and additional guidance to provide a clearer understanding of the medication’s safety.

Researchers said several factors could potentially explain the observed association between cefepime and higher mortality, but they could not identify one cause. Possible explanations included drug levels that were too low to treat an infection effectively and neurotoxicity caused when levels became too high.

Determining the appropriate cefepime dose can be difficult, according to the study. Higher doses may strengthen the drug’s ability to kill bacteria while simultaneously increasing the possibility of toxic side effects.

The research also carried several limitations. Investigators combined clinical trials that varied in design, patient populations, dosing strategies and comparison antibiotics, and some of those trials dated back decades.

Most importantly, the analysis identified an association rather than proving that cefepime caused the higher mortality. Differences among the trials and patients could complicate efforts to determine what drove the gap in outcomes.

Dr. Marc Siegel, Fox News senior medical analyst, said the findings demonstrate why older studies should be reviewed and analyzed again. "In this case, it correctly pointed out that febrile neutropenia (low white blood cell count with a fever) is itself a big cause of death in this population, making it often difficult to determine if the treatment (cefepime) decreases or possibly increases this risk," Siegel, who was not involved in the research, told Fox News Digital.

A closer examination of the data suggests that inadequate dosing and excessive dosing, rather than cefepime itself, may be more closely connected to worse outcomes and a higher risk of death, according to Siegel. That possibility places particular importance on selecting an appropriate dose for each patient.

Siegel also suggested that artificial intelligence could potentially help clinicians address the dosing challenge and evaluate results. "I also think there may be a role for AI here in determining the exact right dose, as well as assessing outcome," Siegel suggested.