New safety labeling changes for fluoroquinolone antibiotics, require these medications to carry stronger warnings about potential mental health side effects and the risk of serious blood sugar disturbances. The US Food and Drug Administration (FDA) announced measures to improve labeling consistency across all fluoroquinolones taken by mouth or administered by injection.
Fluoroquinolones, also known as quinolone antibiotics, are effective against a wide range of bacteria and can be used to treat many different bacterial infections. More than 60 generic FDA-approved fluoroquinolones are available in the United States, as well as several branded medications, such as Levaquin (levofloxacin), Cipro (ciprofloxacin), Avelox (moxifloxacin), and Baxdela (delafloxacin).
FDA recommendations suggest fluoroquinolones not be used for common infections, such as urinary tract infections (UTIs), sinusitis, or bronchitis, due to the risk of serious side effects. In 2008, the agency added a Boxed Warning about the increased risk of tendinitis and tendon rupture, and in 2011, a warning about the risk of worsening symptoms in patients with myasthenia gravis was added.
A further update alerting patients to the potential for irreversible peripheral neuropathy was included in 2013. In 2016, the FDA enhanced warnings about fluoroquinolones, determining that the drugs should be reserved for use in patients with acute bacterial sinusitis, acute bacterial exacerbation of chronic bronchitis, and uncomplicated urinary tract infections for whom there are no alternative treatment options.
“The use of fluoroquinolones has a place in the treatment of serious bacterial infections - such as certain types of bacterial pneumonia - where the benefits of these drugs outweigh the risks, and they should remain available as a therapeutic option,” said Edward Cox, MD, director of the Office of Antimicrobial Products in the FDA’s Center for Drug Evaluation and Research.
Previously, Warnings and Precautions labels on many fluoroquinolones carried information about various mental health side effects, yet these differed between drugs. Under the latest class-wide changes, labels are required to list the following mental health side effects: disturbances in attention, disorientation, agitation, nervousness, memory impairment, and delirium. These will be listed separately from central nervous system side effects and will be consistent across all fluoroquinolones.
A recent FDA review also found certain patients using fluoroquinolones experienced hypoglycemia (low blood sugar) and even hypoglycemic coma in some cases. Consequently, all systemic fluoroquinolones will be required to explicitly state the potential risk of hypoglycemic coma in the Blood Glucose Disturbances subsection of the label.
In March 2018, a team of Swedish and Danish researchers published a study in The BMJ linking treatment with fluoroquinolone antibiotics to an increased risk of acute aortic disease. The researchers suggested the cause of this was increased activity of certain tissue-degrading enzymes, which they posited may also cause the more well-known side effect of tendon pain and rupture.