Levaquin, Cipro May Worsen Myasthenia Gravis: Health Canada

Canadian health officials are warning that a class of antibiotics, which includes Levaquin and Cipro, may worsen the effects of some muscle disorders. 

The antibiotics warning was issued on March 14, by Health Canada and the makers of fluoroquinolone antibiotics, Bayer and Janssen, Inc., a division of Johnson & Johnson. The warning came with a notice that the labels for all antibiotics in that class would be updated.

According to health officials, Cipro, Levaquin and Avelox are associated with a worsening of a muscle condition known as myasthenia gravis, which can cause muscle weakness and breathing problems. While there was already some information about possible effects of these antibiotics on myasthenia gravis, the new label warnings will be stronger and contain more information.

Fluoroquionolones have already been linked to other forms of muscle problems, including tendon ruptures.

In July 2008, the FDA required that a “black box” warning be added about the side effects of Levaquin and other similar antibiotics, which is the strongest warning that can be placed on a prescription medication. However, consumer advocates called for stronger Levaquin tendon rupture warnings to be added at least two years earlier, with Public Citizen filing a petition with the FDA in 2006, insisting that consumers and the medical community be provided with clearer warnings about the risk of tendon damage.

Levaquin is one of the best selling antibiotics in the United States, pulling in about $1.5 billion last year. It is now also available as a generic from other drug makers.

Several thousand Levaquin lawsuits have been filed against Johnson & Johnson by individuals throughout the United States, alleging that the drug maker failed to adequately warn about the risk of tendon damage and tendon ruptures associated with their antibiotic.