European regulators have followed the lead of the US Food and Drug Administration and recommended more restrictions on the use of Sanofi-Aventis’ controversial antibiotic Ketek which has been linked to liver damage.

The European Medicines Agency’s Committee for Medicinal Products for Human Use (CHMP) has proposed restrictions on the use of Ketek (telithromycin), saying that as a treatment of bronchitis, sinusitis and tonsillitis/pharyngitis, the drug should only be used for infections caused by bacterial strains that are suspected or proven to be resistant to or cannot be treated with macrolide or beta-lactam antibiotics. No restrictions are recommended for another indication, the treatment of community-acquired pneumonia, as Ketek’s benefits continue to outweigh the risks,

However, the CHMP also recommended that the existing warning over the use of Ketek in patients with myasthenia gravis, a disease that causes muscle weakness, be upgraded to a contraindication, and said that the prescribing information be updated to strengthen warnings on transient loss of consciousness and effects on vision, including their impact on driving and using machinery. The regulator concluded by noting that the medicine should be taken at bedtime to reduce the impact of these side effects.

Last month, the FDA said that Ketek can remain on the US market as a treatment for pneumonia but Sanofi will no longer be able to promote the drug for sinusitis or bronchitis. That move was the latest in a long-running saga over the safety of Ketek in the USA where after being denied approval by the FDA in 2001 and 2003, it finally made it to market in 2004. However the agency has come under repeated fire from US politicians who claimed that a major safety trial of Ketek used to support approval had "data integrity problems."

Regarding the CHMP’s recommendations, Sanofi defended its product, noting that “severe problems with the liver have rarely been reported with Ketek but they do not occur more frequently than with other relevant antibiotic medicines”. The Franco-German drugmaker added that Ketek, when used with the updated product information, “continues to be an important option in the anti-infective drug armamentarium”. It is currently marketed in over 50 countries and that over 30 million courses of treatment have been prescribed worldwide to date.