(Reuters) – GlaxoSmithKline has made changes in the dosage label for the IV form of its anti-nausea drug Zofran (ondansetron), U.S. health regulators said.
The U.S. Food and Drug Administration on Friday said interim data from a clinical study showed a single 32 mg IV dose of Zofran could cause QT prolongation, putting patients at risk for torsades de pointes.
The updated label removes the 32 mg single IV dose, and says that the drug can continue to be used in adults and children at doses of 0.15 mg/kg every four hours for up to three doses, but no single dose should exceed 16 mg.
Oral dosing remains unchanged, at least for now.
Glaxo conducted the safety study after regulators had voiced concerns last September.
The FDA said in a statement it will evaluate the final study data when available, and will work with Glaxo to explore an alternative single-dose regimen.