Fluoroquinolone antibiotics low blood sugar warning and additional drugs being evaluated for safety concerns

(August 12, 2018) (Cipro information updated November 22, 2021)

In the U.S., the FDA is responsible for continuously monitoring the safety of approved drug products. The FDA Adverse Events Reporting System (FAERS) enables the FDA to conduct "post-market surveillance" by requiring pharmaceutical companies to submit "adverse event reports" for patient safety incidents related to their products. Last month, we reported on the exponential increase in these reports in recent years, along with an explanation of what the FDA does with the data.

Each quarter, the FDA releases a list of drugs that have been flagged for exhibiting new (not already listed on the product label) potential signals of serious safety risks. The list also includes a description of the action that the FDA is taking or has taken. In some cases, the FDA decides not to take any action based on available information. In other cases, they require a change on a product label to bring attention to a new product risk. A recent example is a new required warning on the entire class of fluoroquinolone drugs, which are very powerful antibiotics with a long list of side effects. This warning was issued July 10, 2018:

"The Food and Drug Administration (FDA) is strengthening the current warnings in the prescribing information that fluoroquinolone antibiotics may cause significant decreases in blood sugar and certain mental health side effects. The low blood sugar levels can result in serious problems, including coma, particularly in older people and patients with diabetes who are taking medicines to reduce blood sugar. We are making these changes because our recent review found reports of life-threatening low blood sugar side effects and reports of additional mental health side effects."

The following table lists some commonly prescribed drugs that have adverse effects reported that have been identified in 2017 and 2018 by the FDA for further evaluation. Drug links go to AskaPatient reviews where patients have reported the side effects flagged by the FDA.The list is not complete. Click on the quarterly reports or FDA link below to view complete listings. Update November 2021: Cipro label was updated to warn that breastfeeding is not recommended while taking Cipro (see all Cipro safety-related label changes).
Drugs Under Evaluation for Possible FDA Regulatory Action
Report Date
Fluoroquinolone antibiotics: causing low blood sugar, hypoglycemic coma, and mental health side effects 2017 Q4
resulted in 7/10/2018 label changes
Cipro XR

Proton Pump Inhibitors: causing polyps of stomach and duodenum
2018 Q1

Two Insomnia Medications: causing sleepwalking, abnormal sleep-related events
2018 Q1
Lunesta tablets
Sonata capsules

Allergy/Asthma drug: causing neuropsychiatric adverse effects
2017 Q4
Singulair (Montelukast Sodium) tablets

Orlistat weight-loss drugs: causing neuropsychiatric events*
2017 Q1
Alli capsule
Xenical capsule
*this side effect for Orlistat not reported on AskaPatient as of 8/2018.

Gonadotropin-releasing hormone (GnRH) Agonists: causing musculoskeletal and connective tissue pain and discomfort
2017 Q1
Lupron Depot PED
Supprelin LA
Synarel nasal solution
Chart by AskaPatient.com.

Sources and more reading
-Does the FDA's rapidly growing database of adverse events reports improve drug safety? AskaPatient newsletter: July 1, 2018.
-FDA Potential Signals of Serious Risks/New Safety Information Identified from the FDA Adverse Event Reporting System (FAERS). Scroll to bottom of page for list of quarterly reports.
-Are there any drugs or drug classes that you feel should be removed from the market? Read results of our poll on this topic.
-MedlinePlus description of Cipro, a fluoroquinolon, including new warnings. Cipro is used for serious infections ranging from pneumonia to typhoid fever, plague and inhalation anthrax.