What you need to know about



What effect will the snakebite have on me?

When a venomous snake bites, it usually injects poison, called venom. The venom can have many serious effects, starting with pain, swelling, and skin damage at the bite location. It can also damage your nervous system, heart, stomach, and other organs and cause dangerous bleeding inside your body.

Quick treatment can prevent permanent damage, including loss of part or all of your fingers or toes, injury to your arms or legs, and severe skin, muscle, and nerve problems.

What treatment will I receive?

  • You will receive intravenous CroFab®, a medicine that acts against the snake venom in your body
  • Your first dose of CroFab® (approximately 6 vials) will be followed by up to 60 minutes of observation
    • Tests will tell the doctors how well the treatment is working
    • You may receive additional doses (of approximately 6 vials per dose) of CroFab® if your symptoms are not under control after 60 minutes
  • In order to help lower the risk of long-term snake venom effects, you will receive 3 maintenance doses (2 vials each) of CroFab®. These will be administered every 6 hours


When can I leave the hospital?


Your doctors will discharge you when:

  • You can do typical everyday tasks without help
  • Your pain is under control (with or without pain medicine)
  • You have no other reason to stay in the hospital

After you leave the hospital

  • Keep the area of the bite raised above your heart as much as you can to reduce swelling
  • Go for a check-up 2 to 3 days after you leave the hospital and again at 5 to 7 days
  • Call your doctor at once if you have
    • Unusual bleeding (bleeding gums, easy bruising, or dark, sticky bowel movements)
    • Allergic reactions like itching, redness, wheezing, cough, fever, rash, or muscle or joint pain
    • Swelling that gets worse and that is not relieved by raising the limb
  • For 2 weeks after you go home, avoid unnecessary surgery, dental work, and contact sports
  • For more information, visit or contact your local poison control center


CroFab® Crotalidae Polyvalent Immune Fab (Ovine) is a sheep-derived antivenin indicated for the management of adult and pediatric patients with North American crotalid envenomation. The term crotalid is used to describe the Crotalinae subfamily (formerly known as Crotalidae) of venomous snakes which includes rattlesnakes, copperheads and cottonmouths/water moccasins.

Important Safety Information

The most common adverse reactions reported in the clinical studies were urticaria, rash and nausea. Adverse reactions involving the skin and appendages (primarily rash, urticaria, and pruritus) were reported in 12 of the 42 patients. Two patients had a severe allergic reaction (severe hives and a severe rash and pruritus) following treatment and one patient discontinued CroFab® due to an allergic reaction. Anaphylaxis and hypersensitivity reactions can occur, and patients should be monitored closely during treatment. CroFab® should not be administered to patients with a known history of hypersensitivity to papaya or papain unless the benefits outweigh the risks and appropriate management for anaphylactic reactions is readily available.

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; one patient required rehospitalization and additional antivenin administration. 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. During this period, the physician should carefully assess the need for re-treatment with CroFab® and use of any type of anticoagulant or anti-platelet drug.

Tell your doctor if any side effect bothers you or does not go away. You may also report side effects to the FDA at 1-800-FDA-1088.