Summer Survival Guide: Venomous Snakebite Edition
Summer welcomes a return to favorite outdoor activities. Yet, along with fun in the sun comes some not-so-friendly creatures to be mindful of, namely venomous snakes. Just like us, snakes become more active when the temperatures rise, and with most snakebites taking place during the summer months,[i] it is especially important to know how to avoid and treat a snakebite before heading outdoors.
How to Handle a Snake Encounter
From rural hiking trails to even your own backyard, many people likely will come across a snake this summer. Of the different types of venomous snakes across the U.S., the most common venomous ones are North American Pit Vipers like rattlesnakes, water moccasins and copperheads.[ii] Since it may not be easy to tell if a snake is venomous or not, assume it is and continue to be careful, not stopping to touch or play with the snake, even if it appears dead. Take two giant steps backward to get out of its striking range. Snakes are wild animals — show the snake respect, and let it be.
Seeking Immediate Treatment for a Snakebite
If someone is bitten by a snake, act quickly and take it seriously, regardless of the type of snake or how symptoms initially present. Envenomation, the process through which venom is injected from the bite, is unpredictable. Symptoms can vary widely from patient to patient,[iii],iv with the impact felt in minutes for some cases and in hours for others.iii,[iv] Early and aggressive intervention is critical to gaining initial control over the spread of the venom — the longer the patient is exposed to venom, the greater the potential for long-term, potentially irreversible damage.
The DO's and DON'Ts of Snakebite First Aid
To ensure the victim is treated as soon as possible, dial 911 immediately and transport them to the emergency department. At the hospital, a physician can quickly assess the situation and decide whether to administer a drug called CroFab®, the only FDA-approved treatment to treat all North American pit viper envenomations in adult and pediatric patients.
In addition to seeking medical attention, people can help the victim by keeping the bite area raised, as well as removing the victim’s jewelry and tight-fighting clothes. Another important reminder: Stay calm, both as the victim and their support! Ensuring the victim remains as still as possible will prevent their heart rate from increasing and speeding up the rate at which the venom spreads.
Surprisingly, commonly sought home remedies for bites — applying tourniquets, ice packs, incisions or suction to the site of the bite — end up causing more harm than good.[v] Capturing and killing the snake to bring to the hospital will only lead to potentially more dangerous interaction with the snake.
“There are no particularly game-changing first aid measures like in the old cowboy movies,” says Dr. William Banner, MD, PhD, Medical Director of the Oklahoma Poison Control Center and Clinical Professor of Pharmacy, at the Oklahoma University College of Pharmacy in Oklahoma City. “The cornerstone of venomous snakebite treatment is antivenom and supportive care. CroFab® has been shown to halt the local effects of the bite, including the immediate source of the pain, while resolving other systemic and hematologic effects, like nausea, dizziness and bleeding.[vi],[vii] Seek medical attention as soon as possible, as a snakebite can have serious consequences, which could include life-threatening conditions.”
To remember these tips as you are on the move this summer, the SnakeBite911 App (for iPhone and Android devices) provides access to useful information, from snake safety and basic pit-viper-bite first aid, to bite management and treatment in the emergency room.
What is the most important information I should know about CROFAB?
CROFAB is an antivenom used in an emergency situation to reverse the effects of the venom from a pit viper snake bite.
- Contact your healthcare provider immediately if you experience unusual bruising or bleeding (such as nosebleeds, excessive bleeding after brushing teeth, the appearance of blood in stools or urine, excessive menstrual bleeding, any small purple or red spots on your skin, excessive bruising or persistent oozing from superficial injuries) after hospital discharge. Such bruising or bleeding may occur for up to 1 week or longer following initial treatment.
- Allergic reactions can happen upon use of the drug and can be severe (anaphylaxis).
- Contact your healthcare provider immediately if you experience any signs and symptoms of delayed allergic reactions or serum sickness (such as rash, itching, hives after hospital discharge).
- Patients allergic to papain, chymopapain, papaya extracts, or bromelain (pineapple enzyme), may react to CROFAB.
What is CROFAB?
- CROFAB is a prescription medicine used for the emergency treatment of a pit viper snake bite. This includes rattlesnakes, copperheads and cottonmouths/water moccasins.
- CROFAB is given into the vein as an infusion. The dose is based on the physician’s evaluation of the severity of the patient’s reaction to the snake bite.
Who should not receive CROFAB?
CROFAB should not be administered to patients with a known history of allergic reaction (hypersensitivity) to any of its components, or to papaya or papain unless the benefits outweigh the risks and appropriate management for severe allergic reactions (anaphylactic reactions) is readily available.
What should I tell my healthcare provider before receiving CROFAB?
Before receiving CROFAB, tell your healthcare provider about all of your medical conditions, including if you:
- Are allergic to papain, chymopapain, papaya extracts, or bromelain (pineapple enzyme). People who are allergic to these may react to CROFAB.
- Are pregnant or planning to become pregnant. It is not known if CROFAB can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. It should be given to a pregnant woman only if clearly needed. CROFAB contains a small amount of mercury in the form of ethyl mercury from thimerosal. While there are limited data on administration of ethyl mercury to pregnant women, high and acute doses of methyl mercury have been associated with nervous system and kidney toxicities.
- Are breastfeeding or plan to breastfeed. It is not known if CROFAB passes into human breast milk.
Tell your healthcare provider about the medicines you take, including prescription and over-the-counter medicines, vitamins and herbal supplements.
What are the possible side effects of CROFAB?
CROFAB can cause serious side effects.
- The most common side effects are hives, rash, nausea, itching and back pain
- Allergic reaction (severe hives and a severe rash and itching) has occurred following treatment
- Recurrent bleeding due to the snake venom requiring additional treatment may occur after discharge from the hospital
These are not all of the possible side effects of CROFAB. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
[i] Seifert SA, Boyer LV, Benson BE, Rogers J. AAPCC-database characterization of native U.S. venomous snake exposures, 2001 - 2005. Clinical Toxicology (Phila), 2009;47(4):327 – 335
[ii] Seifert, S. A., White, J., & Currie, B. J. (2011, December). Commentary: Pressure Bandaging for North American Snake Bite? No! The Journal of Medical Toxicology, 324-326.
[iii] Dart RC, Hurlbut KM, Garcia R, Boren J. Validation of a severity score for the assessment of crotalid snakebite. Ann Emerg Med. 1996;27(3):321-326.
[iv] Gold BS, Barish RA, Dart RC. North American snake envenomation: diagnosis, treatment and management. Emerg Med Clin North Am. 2004;22(2):423-443.
[vi] CroFab® [prescribing information]. BTG International Inc; May 2017. 2. Data on file. Conshohocken, PA; BTG International Inc. 2015.
[vii] Dart RC, Seifert SA, Boyer LV, et al. A randomized multicenter trial of crotalinae polyvalent immune Fab (ovine) antivenom for the treatment for crotaline snakebite in the United States. Arch Intern Med. 2001;161(16):2030-2036.