North American coral snake antivenin (Micrurus fulvius) is an equine-derived antivenin administered intravenously to neutralize the toxic effects of coral snake bites. The antivenin is active against venom from eastern coral snakes (Micrurus fulvius fulvius) and Texas coral snakes (Micrurus fulvius tenere), but will not neutralize the venom from Arizona (Sonoran) coral snakes (Micruroides euryxanthus). The antivenin is derived from the blood of healthy horses immunized with venom from the eastern coral snake; thus, allergic reactions may occur in patients with equine hypersensitivity. Consider performing skin sensitivity testing before initiating antivenin therapy. Cases of anaphylaxis and serum sickness have been observed after treatment. Antivenin therapy is the mainstay of medical treatment (in conjunction with supportive care), and is most effective when given at the first sign of systemic envenomation. It is advised to administer the antivenin as soon as the patient develops sign of systemic envenomation; significant delays in treatment may result in neuromuscular weakness that is unlikely to be reversed by the antivenin.
Administration
For storage information, see the specific product information within the How Supplied section.
NOTE: Consider performing skin sensitivity testing prior to administration of the antivenin.
NOTE: Ensure appropriate medications (epinephrine 1:1000, intravenous antihistamines, albuterol) and equipment to treat anaphylaxis are readily available. Observe patients for an acute and delayed allergic reactions and for serum sickness.
Route-Specific Administration
Injectable Administration
-Administered intravenously.
-Visually inspect parenteral products for particulate matter and discoloration prior to administration whenever solution and container permit.
Intravenous Administration
Reconstitution
-Add 10 mL of diluent (Sterile Water for Injection) into each vacuum-containing vial of antivenin.
-While pointing the needle at the center of the lyophilized pellets, allow the vacuum to pull the diluent out of the syringe so that the diluent stream wets the pellets. Continue to allow room air to be pulled into the vial until all vacuum has been released.
-Swirl the vial (do not shake) for 1 minute, at 5-minute intervals until complete dissolution of the lyophilized pellets is observed.
-Complete reconstitution usually requires at least 30 minutes.
Intermittent intravenous infusion or injection
-Start an intravenous infusion of 250 or 500 mL of 0.9% Sodium Chloride Injection.
-Administer the contents of 3 to 5 vials (30 to 50 mL) of antivenin either into the 250 or 500 mL 0.9% Sodium Chloride reservoir bottle or by slow injection directly into the intravenous tubing. If added directly to the reservoir bottle, mix by gentle swirling (do not shake).
-Administer the first 1 or 2 mL of antivenin over 3 to 5 minutes with careful observation of the patient for evidence of allergic reaction. If no signs or symptoms of anaphylaxis appear, continue the injection or intravenous infusion.
-Adjust the rate of delivery based on the severity of envenomation and tolerance of antivenin. Administer at the maximum safe rate for intravenous fluids, based on body weight and general condition of the patient.
--For adults, if given by intravenous infusion to a previously healthy adult, allow 250 or 500 mL to be infused within 30 minutes.
-For small children, allow the first 100 mL to be infused rapidly but then decrease to a rate not to exceed 4 mL/minute. Response to treatment may be rapid and dramatic.
-Observe the patient carefully, and administer additional antivenin intravenously as required.
Subcutaneous Administration
-Subcutaneous administration is for desensitization purposes only.
Other Injectable Administration
Intradermal Administration
-Intradermal administration is for the purpose of sensitivity testing only prior to therapeutic administration of the antivenin, using either normal horse serum or the antivenin.
Hypersensitivity reactions, including anaphylaxis or anaphylactoid reactions, have reported with use of the coral snake antivenin. As the product it is derived from horse serum, the risk for serious reactions may be increased in patients with an equine hypersensitivity. Immediate reactions, such as anaphylactic shock, usually occur within 30 minutes of administration; signs may even develop before the needle is withdrawn and may include apprehension, flushing, pruritus, urticaria, angioedema, cough or dyspnea due to acute bronchospasm, cyanosis, and collapse. Anaphylaxis may be prolonged and resistant to therapy in patients receiving beta blockers. Although serious reactions to antivenin are rare, there have been reports of cardiac arrest and death associated with the use of antivenin (crotalidae) polyvalent (equine origin). Although cardiac arrest has not been reported with coral snake antivenin, the products are very similar, and these reactions cannot be ruled out. Recipients of the coral snake antivenin may experience delayed allergic reactions or serum sickness (rash, pruritus, fever, myalgia, arthralgia, lymphadenopathy, malaise) 5 to 24 days after antivenin administration when patients have most likely been discharged. Advise patients to immediately report any signs or symptoms of serum sickness to their physician or emergency department.
Abdominal pain and vomiting are among the most frequently reported adverse events following treatment with the coral snake antivenin. Due to the voluntary nature of these reports, neither a frequency nor a definitive cause relationship can be established.
Administration of any antivenin requires a specialized care setting with ready access to medications used for the treatment of hypersensitivity reactions (i.e., epinephrine, intravenous antihistamines, albuterol). Patients with an equine protein sensitivity may develop anaphylaxis if exposed to coral snake antivenin, as it is obtained from the blood of healthy horses immunized with eastern coral snake (Micrurus fulvius fulvius) venom. Consider sensitivity skin testing prior to antivenin administration. In addition, a thorough review the patient's history, including any report of asthma, hay fever or other allergies, urticaria, allergic reactions upon exposure to horses, or prior administration of products derived from horse serum should be conducted in an effort to detect the presence of dangerous sensitivity. Careful judgment and considerable experience in the use of antivenin is recommended for the use of coral snake antivenin in patients with an equine protein hypersensitivity, either by history or as a result of an appropriate sensitivity test. Healthcare providers must be prepared to manage immediate, allergic reactions (anaphylaxis) when administering coral snake antivenin. After drug administration, monitor for signs of an acute allergic reactions (e.g., angioedema, bronchospasms, tachycardia, hypotension, cough, stridor, laryngeal edema, urticaria, pruritus, erythema), delayed allergic reaction (e.g., arthralgia, myalgia, rash, fever), and serum sickness. Patients may become sensitized to the antivenin; therefore, use caution when administering a repeated course. Coral snake antivenin must not be administered prophylactically to asymptomatic patients.
No data are available regarding use of the coral snake antivenin during pregnancy. Administer to a pregnant patient only if clearly required.
No data are available regarding use of the coral snake antivenin during breast-feeding, and its excretion into human breast milk is unknown. Administer to a lactating patient only if clearly indicated. Consider the development and health benefits of breast-feeding along with the mother's clinical need for the antivenin and any potential adverse effects on the breast-fed child from the antivenin or the underlying maternal condition.
For the treatment of a North American eastern (Micrurus fulvius fulvius) or Texas (Micrurus fulvius tenere) coral snake bite:
-for sensitivity testing prior to antivenin administration:
NOTE: Coral snake antivenin is prepared from horse serum; consider performing sensitivity skin testing prior to treatment.
NOTE: A negative history and negative skin test do not rule out the possibility of an immediate allergic reaction. Also, a negative skin test has no bearing on if a delayed serum reaction (serum sickness) will occur after administration of the full dose.
NOTE: Administering antivenin to a patient with a positive history and strongly positive skin test may be dangerous. The risk of antivenin administration must be weighed against the risk of withholding antivenin, keeping in mind severe envenomation can be fatal.
Intradermal dosage (for sensitivity testing):
Adults: 0.02 to 0.03 mL of a 1:10 dilution of normal horse serum or antivenin injected intradermally (not under the skin). If the past history suggests sensitivity, use a 1:100 or greater dilution for the skin test. A positive reaction is a wheal (with or without pseudopodia) surrounded by erythema which develops within 5 to 30 minutes. Administer a control test of 0.9% Sodium Chloride Injection to aid in interpretation.
Children and Adolescents: 0.02 to 0.03 mL of a 1:10 dilution of normal horse serum or antivenin injected intradermally (not under the skin). If the past history suggests sensitivity, use a 1:100 or greater dilution for the skin test. A positive reaction is a wheal (with or without pseudopodia) surrounded by erythema which develops within 5 to 30 minutes. Administer a control test of 0.9% Sodium Chloride Injection to aid in interpretation.
-for desensitization prior to administration of antivenin in a patient with a negative history, but a mildly or questionably positive skin test:
Subcutaneous dosage (for desensitization):
Adults: In separate sterile vials or syringes prepare 1:10 and 1:100 dilutions of antivenin. Using a tuberculin syringe, subcutaneously inject 0.1 mL, 0.2 mL, and 0.5 mL of the 1:100 dilution at intervals of at least 15 minutes. Proceed with the next dose only if no reaction occurs with the previous dose. Repeat with the 1:10 dilution, and finally the undiluted antivenin. If there is a reaction after any of the injections, place a tourniquet proximal to the injection sites and administer epinephrine 1:1000 proximal to the tourniquet or into another extremity. Wait at least 30 minutes before giving another injection of the antivenin, the amount of which should be the same as the last one not evoking a reaction. If no reaction occurs after giving 0.5 mL of the undiluted antivenin, switch to the IM route and continue doubling the dose at 15-minute intervals until the entire dose is injected or proceed to the IV route as described below.
Children and Adolescents: In separate sterile vials or syringes prepare 1:10 and 1:100 dilutions of antivenin. Using a tuberculin syringe, subcutaneously inject 0.1 mL, 0.2 mL, and 0.5 mL of the 1:100 dilution at intervals of at least 15 minutes. Proceed with the next dose only if no reaction occurs with the previous dose. Repeat with the 1:10 dilution, and finally the undiluted antivenin. If there is a reaction after any of the injections, place a tourniquet proximal to the injection sites and administer epinephrine 1:1000 proximal to the tourniquet or into another extremity. Wait at least 30 minutes before giving another injection of the antivenin, the amount of which should be the same as the last one not evoking a reaction. If no reaction occurs after giving 0.5 mL of the undiluted antivenin, switch to the IM route and continue doubling the dose at 15-minute intervals until the entire dose is injected or proceed to the IV route as described below.
-for the treatment of coral snake bite:
Intravenous dosage:
Adults: 3 to 5 vials (30 to 50 mL of antivenin) via slow IV injection directly into the IV tubing or reservoir bottle of a 250 or 500 mL Sodium Chloride infusion. Administer the first 1 to 2 mL of antivenin over 3 to 5 minutes. If no signs or symptoms of anaphylaxis are observed, continue the injection or infusion. Adjust delivery rate by the severity of envenomation and tolerance of antivenin. Observe closely and administer additional antivenin as required.
Adolescents: 3 to 5 vials (30 to 50 mL of antivenin) via slow IV injection directly into the IV tubing or reservoir bottle of a 250 or 500 mL Sodium Chloride infusion. Administer the first 1 to 2 mL of antivenin over 3 to 5 minutes. If no signs or symptoms of anaphylaxis are observed, continue the injection or infusion. Adjust delivery rate by the severity of envenomation and tolerance of antivenin. Observe closely and administer additional antivenin as required.
Children: 3 to 5 vials (30 to 50 mL of antivenin) via slow IV injection directly into the IV tubing or reservoir bottle of a 250 or 500 mL Sodium Chloride infusion. In small children, the dose may be decreased depending on response. Administer the first 1 to 2 mL of antivenin over 3 to 5 minutes. If no signs or symptoms of anaphylaxis are observed, continue the injection or infusion. Adjust delivery rate by the severity of envenomation and tolerance of antivenin. Allow the first 100 mL to run in rapidly, then decrease to a rate not exceeding 4 mL/minute. Response to treatment may be rapid and dramatic. Observe closely and administer additional antivenin as required.
Maximum Dosage Limits:
-Adults
3 to 5 vials initially for most envenomations, with additional vials administered as needed.
-Geriatric
3 to 5 vials initially for most envenomations, with additional vials administered as needed.
-Adolescents
3 to 5 vials initially for most envenomations, with additional vials administered as needed.
-Children
3 to 5 vials initially for most envenomations, with additional vials administered as needed.
-Infants
Safety and efficacy have not been established.
-Neonates
Safety and efficacy have not been established.
Patients with Hepatic Impairment Dosing
Specific guidelines for dosage adjustments in hepatic impairment are not available; it appears that no dosage adjustments are needed.
Patients with Renal Impairment Dosing
Specific guidelines for dosage adjustments in renal impairment are not available; it appears that no dosage adjustments are needed.
*non-FDA-approved indication
There are no drug interactions associated with Coral Snake Antivenin, Antivenin Micrurus fulvius Equine products.
The North American coral snake antivenin contains specific antibodies that bind to and neutralize the venom of the eastern coral snake (Micrurus fulvius fulvius). The antivenin activity is standardized for potency in mice in terms of its (Lethal Dose) LD50 neutralizing capacity per mL. Based on this assay system, the reconstituted contents of each vial (10 mL) will neutralize approximately 2 mg of eastern coral snake (Micrurus fulvius fulvius) venom. Results from cross-neutralization tests indicate that the antivenin will also neutralize the venom of the Texas coral snake (Micrurus fulvius tenere) but not the Arizona (Sonoran) coral snake (e.g., Micruroides euryxanthus).
The coral snake antivenin is administered intravenously. No pharmacokinetic data are unavailable.
Affected cytochrome P450 isoenzymes: none