To Investigate the Effect of Intravenous Ondansetron on Cardiac Conduction as Compared to Placebo and Moxifloxacin in Healthy Adult Subjects

Ondansetron, also known as Zofran, is a marketed compound used for the prevention of nausea and vomiting. This study, called a thorough QT study, will characterize the effects of a single intravenous (IV) dose of ondansetron on cardiac repolarization as compared to placebo. Moxifloxacin, a commercially available antibiotic known to cause a mild QT prolongation, will be used as a positive control and will be given orally. The cardiac repolarization will be measured by taking consecutive ECGs on a recording device known as a Holter monitor and measuring the QT interval at specified times. In addition, blood samples will also be taken at specified times and will be used to measure the amount of study medication in the body.