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Ciprofloxacin Licensed To Treat Pneumonic Plague

Yersinia pestis bacteria
Credit: NIAID

Based on data from NIAID, the Food and Drug Administration (FDA) recently licensed the antibiotic ciprofloxacin to prevent and treat pneumonic plague—the least common but most serious form of disease—and septicemic plague caused by Yesinia pestis bacteria. FDA approved the first antibiotic, levofloxacin, in April 2012. FDA also recently approved a third antibiotic, moxifloxacin, using the same animal model developed by NIAID, to treat pneumonic and septicemic plague.

What’s interesting about the FDA approvals is that these antibiotics were not created or initially approved to treat plague, but for ciprofloxacin and levofloxacin, NIAID-supported research helped confirm their added effectiveness. All three drugs are considered broad-spectrum antibiotics, meaning they effectively kill bacteria that cause respiratory, skin, urinary, intestinal, and other types of infections.


In recent years, NIAID has supported animal studies of various FDA-approved antibiotics to determine whether they are effective against infectious diseases other than those for which they were designed. Because so few treatments are available for pneumonic plague, which affects the lungs and can lead to transmission by droplets, it became a testing priority.

Research Advance

For more than a decade, the NIAID Division of Microbiology and Infectious Diseases has supported and helped develop animal models to determine how different systems absorb and tolerate antibiotics and whether those antibiotics are effective treatments against various bacterial challenges. Along with pneumonic plague, for example, the project also has tested licensed antibiotics against tularemia and anthrax.


Having an expanded choice of licensed treatments strengthens and adds depth to public health systems, particularly in large outbreaks where treatment availability might be limited.​​

Content last reviewed on May 20, 2015