FDA Response to Citizen Petition on Arsenic-based Animal Drugs
On September 30, 2013, FDA denied a petition from the Center for Food Safety and the Institute for Agriculture and Trade Policy that asked the agency to take steps to revoke the approvals of four arsenic-based animal drugs. The petitioners’ requests with respect to three of the four drugs at issue became moot after the sponsors of those drugs requested that FDA withdraw the approvals for those products. With respect to the only remaining approved arsenic-based animal drug, FDA denied the petitioner’s request because the agency is in the process of completing several scientific studies and reviewing and evaluating information to help the agency more fully evaluate any potential concerns related to the safety of arsenic-based animal drugs. The agency has decided to review this information before reaching any conclusions about whether there may be grounds to initiate proceedings to withdraw approval of nitarsone, the only currently marketed arsenic-based animal drug in the U.S.