History of Snakebite Treatments

Antivenin Crotalidae Polyvalent (Wyeth-Ayerst Laboratories, Inc.) was the first modern snakebite treatment. It was manufactured from horse serum and contained protective substances capable of neutralizing the toxic effects of venoms of crotalids (pit vipers) including rattlesnakes, copperhead and cottonmouth moccasins. It was available beginning in the early 1950s. Side effects of the treatment included fever and rash; additionally, it could cause severe and sometimes fatal allergic reactions in humans.

In May 2001, Wyeth-Ayerst Laboratories announced that they expected to sell out of their Antivenin for at least the months of May and June. This was the second year in a row that Wyeth had experienced production shortfalls. In the Summer of 2000 there were also widespread shortages of their Antivenin. Unfortunately, at the time, it was the only treatment available.

In October 2000, the first new snakebite treatment in 50 years was approved. CroFab^®; - Crotalidae Polyvalent Immune Fab (Ovine) (Altana Inc.) is indicated for the management of patients with minimal or moderate North American crotalid envenomation. CroFab^®; was developed from sheep serum. The most common adverse events reported in clinical studies with CroFab^®; were mild or moderate reactions involving the skin and appendages (primarily urticaria, rash or pruritis) observed in 14 out of 42 patients. Severe allergic reactions occured in 2 out of 42 patients studied.*

The administration of an antivenom should be initiated as soon as possible (within six hours) after poisonous snakebites in patients who develop signs of progressive envenomation, i.e. worsening of local injury, coagulation abnormality, or systemic signs of envenomation.

*For additional events, precautions or warnings, please refer to the full prescribing information.

CroFab^®; - Crotalidae Polyvalent Immune Fab (Ovine) is distributed by Fougera® and Savage Laboratories®, divisions of Altana Inc., Melville, New York 11747.