NORTH AMERICAN PIT VIPER SNAKEBITE SEASON
In the United States, the majority of North American pit viper* snakebites occur in warmer months, typically April through September, with incidence peaking in July.
- Warmer, more southern states―such as Texas, Florida, California, North Carolina, Arizona, Louisiana, and Georgia―typically report the largest number of venomous snakebites
*The term pit viper is used to describe all species of North American rattlesnakes, copperheads, and cottonmouths (water moccasins).
THE SNAKEBITE TREATMENT ALGORITHM
For information about how to manage a patient with North American pit viper envenomation, click on the link below to access the consensus treatment algorithm Management of North American Pit Viper Envenomation.
CroFab® Crotalidae Polyvalent Immune Fab (Ovine) is an antivenin indicated for the management of patients with North American crotalid envenomation. The term crotalid is used to describe the Crotalinae subfamily (formerly known as Crotalidae) of venomous snakes that includes rattlesnakes, copperheads, and cottonmouths/water moccasins. Early use of CroFab® (within 6 hours of snakebite) is advised to prevent clinical deterioration and the occurrence of systemic coagulation abnormalities.
Important Safety Information
The most common adverse events reported in clinical studies were mild or moderate reactions involving the skin and appendages (primarily urticaria, rash, or pruritus), which occurred in 14 out of 42 patients. Three patients experienced a serious adverse event. Two patients had a severe allergic reaction (severe hives and a severe rash and pruritus) following treatment. One patient had a recurrent coagulopathy due to envenomation, which required rehospitalization and additional antivenin administration. In clinical trials, recurrent coagulopathy (the return of a coagulation abnormality after it has been successfully treated with antivenin), characterized by decreased fibrinogen, decreased platelets, and elevated prothrombin time, occurred in approximately half of the patients studied. Recurrent coagulopathy may persist for 1 to 2 weeks or more. Patients who experience coagulopathy due to snakebite should be monitored for recurrent coagulopathy for up to 1 week or longer. One patient discontinued CroFab® therapy due to an allergic reaction. Anaphylaxis and hypersensitivity reactions can occur, and patients should be monitored closely during treatment. Patients with allergies to papain, chymopapain, other papaya extracts, or the pineapple enzyme bromelain may also be at risk for an allergic reaction to CroFab®. CroFab® contains mercury in the form of ethyl mercury from thimerosal. The final product contains up to 30 mcg or approximately 0.03 mg of mercury per vial, which amounts to no more than 0.6 mg of mercury per dose (based on the maximum dose of 18 vials studied in clinical trials of CroFab®).