CORAL SNAKE & ANTIVENIN FAQ’s
Why is there shortage of Coral Snake Antivenin?
On May 18, 2010, Pfizer Inc responded to this question with the following statement: "Wyeth discontinued manufacturing Coral Snake Antivenin in 2003 following closure of the plant where the product had been manufactured. This was done with the full knowledge of the FDA. At that time, FDA requested that Wyeth manufacture a five year supply to allow time for another manufacturer to obtain FDA approval for a new product. Wyeth manufactured the supply but, to date, no other company has received FDA approval."
Why is the product referred to as "antivenin" and not "antivenom"?
The product name as it was licensed by the FDA is Antivenin (Micrurius fulvius) North American Coral Snake Antivenin. Medical professionals refer to the product by that name.
How much Antivenin is still available?
Pfizer still has Coral Snake Antivenin for purchase. It is estimated that the current supply of the extended lot could last up to 18 months.
How can a hospital obtain a supply of antivenin?
Hospital pharmacists can order replacement supplies of Lot #4030026 from Pfizer.
Contact Pfizer Customer Service at 800-666-7248. Lot #4030024 is also available. If you have problems ordering, please call the Poison Center for help.
What will happen when the antivenin supply is exhausted?
Efforts are being made to ensure that an alternative antivenin will be available. Please see the What’s Being Done section.
How effective is the antivenin treatment?
Medical data describing patient cases prior to antivenin usage is not very reliable since there was no organized surveillance in the past. Before antivenin was developed in 1967, the fatality rate was reported to be as high as 10-20%. Once antivenin became the mainstay of care, it was recommended to administer Antivenin before the onset of symptoms. Using this standard, the prognosis has been excellent and full recovery was expected. Most snake bite victims could be discharged within 24 hours. However, all bites may not need antivenin. To further extend the availability of antivenin, judicious use of antivenin after careful ICU monitoring is now recommended. Please contact the Poison Center at 1-800-222-1222 to obtain the most current recommendations. It is imperative that the Poison Centers be notified as Poison Centers are the only surveillance mechanism for these potentially life-threatening bites.
What testing has been done to ensure that the extended lot of antivenin can be used?
On April 19, 2010, Pfizer Inc. responded to a request for clarification of testing of the antivenin. "Antivenin Coral Snake has continued to maintain its quality attributes for approximately 2 years after expiration. Pfizer Inc. is currently planning for additional testing to determine whether the expiration dating may be extended again. Testing includes the product, closure and excipients. The FDA is aware of all testing performed. The FDA must review and approve all of the test results prior to FDA granting an extension of the expiration dating. In addition to tests of physical appearance (lyophilized and reconstituted), there is chemical testing of the product that includes potency and pH. Sterility, moisture and vacuum tests are also performed to give information on the integrity of the closure system."
Note: Excipients refers to inactive ingredients added to as a vehicle or a carrier of the active ingredient.
About Coral snake bites:
What happens when a person is bitten?
Coral snake venom is a complex mixture of proteins that includes postsynaptic neurotoxins. The neurotoxic effects of the coral snake venom are manifested by muscle weakness, difficulty speaking, difficulty swallowing, difficulty breathing, unable to move eyelids (ptosis), blurred vision (diplopia), tongue fasciculations (twitching), decreased oxygen saturation, paralysis, and potential respiratory arrest. The cranial nerve signs are known as a bulbar paralysis. On occasions, patients with slurred speech have been presumed to be intoxicated. A patient may face weeks of ventilator support with risks of subsequent pneumonia, tracheotomy and multi-system failure. Long term rehabilitation may be needed for neuromuscular damage and atrophy resulting from the paralysis.
Prophylactic use of antivenin has been effective in preventing these signs and symptoms. Case reports of patients receiving antivenin in a delayed fashion show that symptoms can progress to paralysis over a 12-18 hours period. In the last 40 years, there has been only one fatality reported. That death occurred because a victim did not seek medical treatment after a bite.
What does the bitten area (bite site) look like?
The Coral snake does not dart or strike like rattlesnakes and other pit vipers, but delivers venom slowly by hanging on, using a chewing technique. Blood at the puncture site signals that the skin has been broken and a possible envenomation has occurred. The mild signs around the bitten area and the delayed onset of symptoms (up to 18 hours) often lead people to believe that no damage has been done. Patients must be observed for a minimum of 24 hours in an intensive care unit.
How many bites occur each year?
An average of 47 bites of humans have been reported to Florida’s Poison Centers during each of the last 10 years. (link to map). The pattern shows that the majority of those bites have been treated in the central and southern parts of the state, along the Peninsula of the state.
About coral snakes:
What is the Latin name and classification for Eastern coral snakes?
Micrurus fulvius in Elapidae family
Where are coral snakes found?
Eastern coral snakes are found in the southeastern USA (see map). Their preferred habitat is pine/oak scrub, but they have been sighted in suburbs. There is a related species in Texas. Other related species are found in Central America and other regions of the world.
How can the Eastern Coral snake be identified?
Multi-colored rings encircle its body with red, black and yellow bands. Every other band is yellow. Red bands touch yellow bands. The nose is black. The pupils are round. Teeth are small (see bite pattern diagram). It does NOT have large fangs like pit vipers. The head is the same width as the rest of the body and does NOT have a large head like pit vipers. The average size is about two feet long. Although the color pattern is usually as described, some variations have been reported. It is imperative to consider the possibility of coral snake with any snake that might be similar.
About treatment of coral snake bites:
What is appropriate first aid treatment for coral snake bites?
- Contact the Poison Center immediately 1 (800) 222-1222.
- Call EMS or go to an Emergency Department immediately.
- Take a photograph of snake if possible or get good description of snake to provide to Poison Control, Emergency Medical Services, or Emergency Department Personnel.
- Rest the envenomated limb lower than the heart.
- Wash bite with soap and water to remove venom on skin surface.
- Remove all jewelry and constrictive clothing from the extremity.
- Attempt to capture or kill snake, which may lead to additional bites.
- Apply arterial or venous tourniquets which may cause a build up of toxins which when released.
- Incise the bite and attempt to suck out venom.
- Use electrical shock-not proven as a treatment in envenomation.
- Apply commercial snakebite venom extractors-shown to be of no benefit in removing adequate amounts of venom.
What is the appropriate medical management for coral snake bites?
- Notify the Poison Center immediately. All patients should be admitted to an ICU for 24 hours of observation due to possible delayed effects.
- Keep patient NPO to prevent aspiration.
- Establish a large-bore IV site and infuse a maintenance IV solution.
- Update tetanus immunization if needed.
- Apply cardiac monitor and pulse oximeter. Monitor vital signs and mental status every 30 minutes, especially respirations.
- Obtain blood for CK level to monitor for myotoxic damage.
- Perform baseline and serial peak flow spirometry every 2 hours.
- Perform ABG immediately for respiratory distress, or decreasing peak flow or oxygen saturation measurements.
- Avoid narcotics or sedatives which may mask neurologic effects and suppress respirations.
- Immediately intubate and ventilate aggressively for signs of respiratory distress, hypoxia, altered mental status or seizures.
- Antibiotics are generally not indicated.
- DO NOT ADMINISTER CROFAB®.
When should Antivenin therapy be administered?
In 2001, Wyeth discontinued production of coral snake antivenin. Antivenin remains available, but supplies are decreasing. In order to preserve remaining antivenin, the Florida Poison Information Centers recommend that health care providers call the Poison Center for current recommendations for antivenin therapy, and assistance in locating a supply. Please be aware that recommendations may change as a result of supply issues or as a result of patient responses, so it is advisable to check with each patient.
Last updated 5/13/10