Cipro, similar antibiotics can cause tendon ruptures, FDA warns

The U.S. government has imposed its most urgent warning on Cipro and similar antibiotics.

The Food and Drug Administration warns that such drugs can cause tendon ruptures, a serious injury that leaves some patients incapacitated.

The FDA is ordering makers of fluoroquinolone drugs — a potent class of antibiotics — to add a "black box" warning to their products, which include Cipro, Levaquin, Floxin and other medications.

It says patients should immediately stop taking the medications if they develop any tendon pain, swelling or inflammation.