Glaxo Wellcome has given further information on the reason for the withdrawal last week of its antibiotic Raxar (grepafloxacin) (PJ, October 30, p701).
The company says that a review of the drug showed that some patients might be at risk of torsades de pointes, a rare but serious ventricular arrhythmia, because of an effect on cardiac repolarisation, manifested as QT interval prolongation. From 2.65m patient treatments prescribed, there have been two confirmed reports and one unconfirmed report of non-fatal torsades de pointes. There have also been seven deaths among patients taking the drug in which a causal relationship with treatment could not be excluded.