Drug Information for Wyeth Antivenin (Micrurus fulvius) (Equine Origin) North American Coral Snake Antivenin (Wyeth Pharmaceuticals Company): Composition

Antivenin (Micrurus fulvius), Wyeth, is a refined, concentrated, and lyophilized preparation of serum globulins obtained by fractionating blood from healthy horses that have been immunized with eastern coral snake (Micrurus fulvius fulvius) venom. Prior to lyophilization, the product contains 0.25% phenol and 0.005% thimerosal (mercury derivative).

Antivenin (Micrurus fulvius), Wyeth, is standardized for potency in mice in terms of its LD₅₀ neutralizing capacity per milliliter as determined by intravenous injection of a graded series of Antivenin—M.f. fulvius venom mixtures. Based on this assay system, the reconstituted contents of each vial (10 ml) will neutralize approximately 250 mouse LD₅₀ or approximately 2 mg of M.f. fulvius venom.

The results of cross-neutralization tests indicate that Antivenin (Micrurus fulvius), Wyeth, will neutralize the venom of M. fulvius tenere (Texas coral snake) but will NOT neutralize the venom of Micruroides euryxanthus (Arizona or Sonoran coral snake).