The intravenous formulation of a drug used to prevent chemotherapy-related nausea and vomiting increases the risk of torsade de pointes and should no longer be used for this indication in children or adults, the Food and Drug Administration announced on Dec. 17.The drug is dolasetron mesylate, a serotonin 5-HT3 receptor antagonist marketed as Anzemet by Sanofi-Aventis US. Confirming previous suspicions about the IV drug's effects on the QT interval, a study of 80 healthy adults found that IV dolasetron...