The United States health regulators Food and Drug Administration (FDA) are looking at the safety of GlaxoSmithKline's anti-nausea drug Zofran generically known as ondansetron, to ascertain whether there is a potential risk of abnormal heart rhythm.
According to the FDA in a statement, the drug may increase the risk of developing abnormal changes in the electric activity of the heart, leading to a potentially fatal heart rhythm.
The FDA has requested GSK to conduct a study on whether Zofran could prolong a patient's QT interval, a measure of heart rhythm. The results of the study are expected in summer of 2012.
FDA until then announced on its website that it was making interim changes to the drug's labels to include a warning that Zofran be avoided in patients with congenital long QT syndrome.