The Food and Drug Administration (FDA) is facing pressure to amend the warning label of Levaquin and other antibiotics in its class to include serious and sometimes fatal side effects of the fluoroquinolones.
Cleveland television station ABC5 (WEWS) obtained a 2013 Food and Drug Administration (FDA) database that contains 3,000 reported deaths and 200,000 complaints related to Levaquin (levofloxacin), Cipro (ciprofloxacin) and other drugs in their class.
Side effects of the fluoroquinolones include tendinitis, tendon ruptures, liver damage, severe diarrhea, heart rhythm changes, blood sugar level changes, and nerve damage to the arms and legs, according to the National Library of Medicine (of the National Institutes of Health). Tendinitis and tendon rupture may occur after the individual has stopped taking the medication. Since 2008, fluoroquinolones have carried a black box warning—the FDA’s most serious drug label warning—and in 2013 the FDA expanded the black box warning to include both ruptured tendons and nerve damage.
But fluoroquinolone labels do not warn about mitochondrial toxicity, another serious side effect that researcher Dr. Charles Bennett says should be included on the label. Bennett, a drug researcher at the University of South Carolina, who holds the endowed chair at the Medication Safety and Efficacy Center of Economic Excellence (CoEE), explains the importance of mitochondria to the body’s functioning. Mitochondria are the body’s “gas tank,” and without mitochondria, “there is no gas in the tank and your body cannot function.” Last year Bennett filed a petition with the FDA urging an expanded warning for fluoroquinolones to include mitochondrial toxicity. The FDA said it is giving the petition “our careful attention” and is “considering the matters raised by the petition,” according to WEWS.
The symptoms of mitochondrial toxicity include muscle weakness, peripheral neuropathy (numbness of fingers and toes), and pancreatitis. The most severe symptom is lactic acidosis, in which a build-up of lactic acid in the tissues leads to loss of energy, organ failure, and eventually death. According to the Mayo Clinic, the brain, heart, liver, muscles, kidneys and the endocrine system most frequently experience damage from mitochondrial toxicity.
Janssen Pharmaceuticals, a unit of Johnson & Johnson, and the maker of Levaquin, said the company “collects and monitors information . . .on the safety and effectiveness of all our medicines, and, in cooperation with the US FDA and other health authorities, we incorporate new data into our product labels so doctors and patients can make informed decisions.” But Bob Paddock, whose wife, Karen, suffered serious effects from Levaquin, said his wife was not aware of the original warning related to tendon damage when she took the drug. Paddock told the television station that the side effects left her unable to walk and after years of struggling with pain in all of her limbs, Karen Paddock took her own life.
Despite the evidence of mitochondrial toxicity related to the fluoroquinolones, it could take another year or longer before the FDA makes a decision on the petition for expanded warnings, according to WEWS.