Unlike the rattlesnake antivenin used in the United States over the previous 50 years, CroFab antivenin (approved by the US Food and Drug Administration in October 2001) uses Mojave rattlesnake venom A (in addition to venom from three other species) in its manufacture,Protherics, Inc. 2004. CroFab Crotalidae Polyvalent Immune FAB (Ovine). [Package insert] making it particularly effective for treatment of venom A Mojave rattlesnake bites. Antibodies in CroFab produced by the other three species' venoms effectively neutralize Mojave rattlesnake venom B.
