Ketolide antibiotics

Telithromycin is the first ketolide antibiotic to enter clinical use and is sold under the brand name of Ketek. It is used to treat community acquired pneumonia of mild to moderate severity. After significant safety concerns, the US Food and Drug Administration sharply curtailed the approved uses of the drug in early 2007.

thumb|right|Telithromycin Ketolides are antibiotics belonging to the macrolide group. Ketolides are derived from erythromycin by substituting the cladinose sugar with a keto-group and attaching a cyclic carbamate group in the lactone ring. These modifications give ketolides much broader spectrum than other macrolides. Moreover, ketolides are effective against macrolide-resistant bacteria, due to their ability to bind at two sites at the bacterial ribosome as well as having a structural modification that makes them poor substrates for efflux-pump mediated resistance.

Cethromycin, trade name Restanza (initially known as ABT-773) is a ketolide antibiotic undergoing research for the treatment of community acquired pneumonia (CAP) and for the prevention of post-exposure inhalational anthrax, and was given an "orphan drug" status for this indication. Originally discovered and developed by Abbott, it was acquired by Advanced Life Sciences Inc. for further development.