The FDA is notifying healthcare professionals, particularly surgery and oncology specialists, that the 32 mg, single intravenous (IV) dose of the anti-nausea drug ondansetron hydrochloride (Zofran, GlaxoSmithKline) will no longer be marketed because of the potential for serious cardiac risks.

The 32 mg, single IV dose of Zofran had been used to prevent chemotherapy-induced nausea and vomiting. A previous Drug Safety Communication (DSC), issued on June 29, communicated that the 32 mg, single IV dose should be avoided due to the risk of a specific type of irregular heart rhythm, called QT interval prolongation, which can lead to Torsades de Pointes. These drugs are sold pre-mixed in solutions of either dextrose or sodium chloride in plastic containers.

The agency anticipates these products will be removed from the market through early 2013.

The FDA also does not anticipate that removal of the 32 mg IV dose of ondansetron currently sold as pre-mixed injections will contribute to a drug shortage of IV ondansetron, as the 32 mg dose makes up a very small percentage of the current market. The agency said it continues to recommend the IV regimen of 0.15 mg/kg administered every four hours for three doses to prevent chemotherapy-induced nausea and vomiting. Oral dosing of ondansetron remains effective for the prevention of chemotherapy-induced nausea and vomiting. At this time, there is not enough information available for FDA to recommend an alternative single IV dose regimen.

The specific list of ondansetron products to be voluntarily withdrawn from the U.S. market are listed on the FDA’s website.