Makers of fluoroquinolone antibiotics are strongly requested by the U.S. Food and Drug Administration to add a black box warning patients about the risks of tendon ruptures.

Fluoroquinolone antibiotics, used to treat bacterial infections, are sold by several drug makers under various brand and generic names. Their labels already warn about the risk of tendon ruptures but do not include black box warnings. Such ruptures most frequently involves the Achilles tendon, but also include ruptures of the shoulder, hand, biceps and thumbs, according to a posting on the FDA’s Web site on Tuesday.

The risk of tendon ruptures is “especially increased” in patients older than 60, and those with kidney, heart or lung transplants.

The fluoroquinolone antibiotics targeted by the black box request include ciprofloxacin sold by Bayer A.G. under the brand names Cipro, Ciproxin and Ciprobay, which is effective against both Gram-positive and Gram-negative bacteria. The same class involves levofloxacin sold by Ortho-McNeil under the trade name Levaquin. The drug is usually used in respiratory infections.

Factive (gemifloxacin), Avelox (moxifloxacin), Noroxin (norfloxacin) and Floxin and generic ofloxacin are also targeted by the black box request.

In 2006, consumer group Public Citizen petitioned the FDA to add black box warnings to these antibiotics after government data showed 262 reported tendon ruptures, 258 cases of tendonitis and 274 other tendon disorders through the end of 2005. Earlier this year, the consumer group sued the FDA. Sidney Wolfe, head of Public Citizen's Health Research Group, told Reuters that since 2005, roughly 100 more cases of tendon ruptures have been reported.

The FDA’s request regarding fluoroquinolone antibiotics comes the same day the agency asked companies selling epilepsy drugs to add a black box on their labels warning about the risk of suicidal thoughts and behavior. Such drugs include, Lamictal, Lyrica, Topamax, Depakote, Neurontin, Felbatol, Keppra, Trileptal, Zonegran.

The FDA’s decision was based on the analysis of 199 studies, which found that those taking the drugs face twice the risk of people who are not on anti-epileptic drugs.