On July 10th, 2018, the U.S. Food and Drug Administration (FDA) reinforced the warning of drug safety information by making changes to the safety labels for fluoroquinolones . Fluoroquinolones are a class of antibiotics approved for the treatment or prevention of certain bacterial infections, and are used in animal husbandry. This class of antimicrobials include gemifloxacin, levofloxacin, moxifloxacin, and ofloxacin, and ciprofloxacin, the latter of which is one of the most widely used antibiotics across the world. Fluoroquinolones are the only class of antibiotics for clinical used which directly inhibit bacterial DNA synthesis . The most commonly reported side effects associated with fluoroquinolones includes rash, hypoglycemia, hyperglycemia, and effects on tendons, gastrointestinal tract, and central nervous system . The most frequent adverse effect involves gastrointestinal toxicity, followed by adverse effects involving the central nervous system .
The FDA prioritized updating safety labels for fluoroquinolones because use of the drug may result in a significant decrease of blood glucose or even mental health side effects. According to FDA Drug Safety Communication, the drug labels should become consistent across the entire class of fluoroquinolones, both taken by mouth and given intravenously .
The changes to the safety labels required by FDA are based on a comprehensive review of the FDA’s adverse event reporting system (FAERS) and case reports published in medical literature, specifically including life-threatening low blood sugar side effects and reports of additional mental health side effects . Blood sugar disturbance is already existing in the current drug label; however, the FDA states that low blood sugar level, or hypoglycemia, may lead to hypoglycemic coma, a serious side effect which needs to be added to boxed warnings. Patients who take hypoglycemic agents to reduce their blood glucose level are more likely to be at risk of a hypoglycemic coma when taking fluoroquinolones. Additionally, mental health side effects will be more clearly differentiated from other central nervous system side effects, and will be labeled more consistently. Previous labels only differed by individual drug. The mental health side effects from fluoroquinolone include disturbances in attention, disorientation, agitation, nervousness, memory impairment, and a severe disturbance called delirium .
The FDA has issued several changes regarding the drug safety of fluoroquinolones since 2008. In July 2008, the FDA added the boxed warning of increased risk of tendon damage . In 2011, the risk of worsening symptoms was indicated for the patients with myasthenia gravis, and in 2013, a label change was required to better describe the potential risk of peripheral neuropathy . The warning was enhanced by the FDA in 2016, when patients with conditions of acute sinusitis, acute bronchitis, and uncomplicated urinary tract infections, were advised against being prescribed fluoroquinolones by healthcare providers because it was determined that the risk outweighs the benefits of use .
To ensure safety, the FDA advises patients to disclose to healthcare professionals if they are taking medication to treat diabetes, particularly when the providers are considering to prescribe fluoroquinolones. Patients are also advised to let their providers know if they suspect they have symptoms of low blood sugar. Additionally, healthcare professionals should be aware of the potential risk of hypoglycemia and hypoglycemic coma, and offer patients a Medication Guide with each time of fluoroquinolone prescription. If a patient reports serious adverse effects relating to their tendons, muscles, joints or nerves issue, healthcare providers should stop fluoroquinolone treatment immediately and consider other available antibiotic options .