In a Federal Register notice today (here), FDA announced its finding that Ondansetron Hydrochloride Injection USP, in plastic, ready-to-use containers containing 32mg/50mL was removed from the market and withdrawn for safety reasons.

In a September 2011 Drug Safety Communication (here), FDA stated concerns relative to the “risk of abnormal in the electrical activity of the heart, which could lead to potentially fatal abnormal heart rhythm” called Torsades de Pointes.  Based on the FDA’s concern, they asked the innovator to conduct a study to “assess the risk.”   The study confirmed a “significant QT prolongation effect in conjunction with the 32 mg dose.”  Under the regulations at 21CFR 314.161, FDA may (at any time) review a previous safety or efficacy determination based on new information that becomes available to the Agency, and, as a result of the findings of the study, confirming the heart rhythm abnormality that could occur at that dose, the FDA is taking action to notify the public that the 32mg/50mL dose is no longer considered safe.   Other strengths of ondansetron injection have not been implicated and remain on the market.

Because of the finding outlined in the FR notice, FDA removed the products from the Orange Book and will no longer accept or approve ANDAs that refer to the 32mg/50mL Ondansetron product.