Some Antibiotics Linked To Tendon Rupture; Public Citizen Petitions FDA For Stronger Warnings

Targets Fluoroquinolone Class of Antibiotics: Tequin, Levaquin, Cipro, et al.

The consumer advocacy group Public Citizen filed a petition with the FDA in late August 2006 requesting that the agency order drug companies to put a "black-box" warning about the risks of tendon rupture that have been associated with a class of antibiotics known as fluoroquinolones.  Some of these antibiotics are Bristol-Myers Squibb's Tequin, Ortho-McNeil's Levaquin, and Bayer's Cipro.

The August 2006 Public Citizen petition concerning antibiotics in the fluoroquinolone class also urged the FDA to require the drug companies to send out so-called "Dear Doctor" letters regarding the stronger warning and to requires pharmacists to issue patient medication guides showing the stronger warning.

According to an August 29, 2006 Associated Press article at least one of the affected drug companies thought the current label was adequate:

Levaquin's label already "clearly states" tendon rupture can occur during or after treatment with the antibiotic, said Ambre Morley, a spokeswoman for Ortho-McNeil Inc., the Johnson & Johnson subsidiary that makes the drug.

Jennifer Corbett Dooren, of Dow Jones Newswire, reported why Public Citizen disagreed with that position in a piece published by The Wall Street Journal on August 29, 2006:

The drug labels do warn of the risk of tendon ruptures but the warning is not contained in a black-box, which is considered the FDA's toughest warning. A black box warning is in bold type and is surrounded by a black box to make it stand out. It typically appears at the top of drug labels and any advertising of products that carry black boxes must also include warning information as part of the advertisement.

Public Citizen said the tendon warning is buried in a list of possible adverse reactions to the drugs and is not adequate to warn consumers and health-care providers of the risk. The current tendon warning was added after Public Citizen petitioned the agency asking for such a warning in 1996.

According to the August 2006 Public Citizen petition, the antibiotic-induced tendon ruptures have occurred in the Achilles tendon, the rotator cuff (shoulder), the biceps, the hand, and the thumb. The petition states that one causation theory is that fluoroquinolones are toxic to tendon fibers and may decrease blood supply in tendons that already have a limited blood supply.

As an aside, in April 2006 Bristol-Myers said that it would stop selling Tequin for other reasons.

P.S.  On July 8, 2008 the FDA announced that a so-called "black-box" Warning would be added to the package insert, or label, to strengthen existing warnings about the increased risk of developing tendinitis and tendon rupture associated with the following fluoroquinolones:

Ciprofloxacin (marketed as Cipro and generic ciprofloxacin)
Ciprofloxacin extended release (marketed as Cipro XR and Proquin XR)
Gemifloxacin (marketed as Factive)
Levofloxacin (marketed as Levaquin)
Moxifloxacin (marketed as Avelox)
Norfloxacin (marketed as Noroxin)
Ofloxacin (marketed as Floxin and generic ofloxacin)

For more details, see the July 8 press release, "FDA Requests Boxed Warnings on Fluoroquinolone Antimicrobial Drugs".  (7/9/08)

(Posted by: Tom Lamb)