"Fluoroquinolones are effective in treating certain bacterial infections, but health care professionals and patients need to be aware of the increased risk associated with the use of these drugs of developing tendinitis and tendon rupture," Edward Cox, director of the FDA's Office of Antimicrobial Products, said in a statement issued Monday.
"The FDA believes it is important to highlight and strengthen information regarding possible side effects of fluoroquinolones because it may affect decisions about the relative risks and benefits associated with these products," he said.
Fluoroquinolones, such as the antibiotic Cipro, are used to treat bacterial infections such as some forms of cystitis, urinary tract infections, chronic bacterial prostatis, lower respiratory tract infections and sinusitis, among other conditions.
The drugs already carry warnings of tendon rupture, but "large numbers of tendon-related adverse events continue to be reported," the FDA said.
The risk of developing tendinitis and tendon rupture as a result of fluoroquinolone is greater among the over-60 population, in those taking corticosteroid drugs, and in kidney, heart, and lung transplant recipients, according to the FDA.
The beefed-up warnings would not apply to eyedrops containing fluoroquinolones.
Besides Cipro, other medications that are impacted by the FDA action are Proquin XR, Factive, Levaquin, Avelox, Noroxin and Floxin.