North American Coral Snake Antivenin (Equine)

North American Coral Snake Antivenin (Equine) is indicated only for the treatment of envenomation caused by bites of North American coral snakes - Micrurus (including the eastern and Texas varieties).

For intravenous use only.

Each package contains one single use vial with lyophilized North American Coral Snake Antivenin (Equine) for dilution with 10 mL of diluent (Sterile Water for Injection, USP). Contents of each reconstituted vial can neutralize approximately 250 mouse (Lethal Dose) LD₅₀ or approximately 2 mg of M. f. fulvius venom.

• Do not administer North American Coral Snake Antivenin (Equine) prophylactically to asymptomatic patients.¹
• Do not administer North American Coral Snake Antivenin (Equine) to patients with a known history of hypersensitivity to horse serum unless the benefits outweigh the risks and appropriate management for anaphylactic reactions is readily available.

The most common adverse reactions observed after treatment with North American Coral Snake Antivenin (Equine) were anaphylaxis and serum sickness, vomiting, and abdominal pain. Because these reactions were reported voluntarily from a population of uncertain size, it is not always possible to estimate their frequency reliably or to establish a causal relationship to drug exposure.

North American Coral Snake Antivenin (Equine) is a sterile lyophilized powder for solution for injection containing serum globulins obtained by fractionating blood from healthy horses that have been immunized with eastern coral snake (Micrurus fulvius fulvius) venom. Prior to lyophilization, the product contains 0.25% phenol.

There have been no well-controlled clinical studies of the use of North American Coral Snake Antivenin (Equine) in patients experiencing envenomation by the Eastern Coral Snake, however a retrospective analysis³ has been published of 387 coral snake exposures treated in a healthcare facility in Florida between 1998 and 2010, including 252 patients who were treated with North American Coral Snake Antivenin (Equine). Patients were managed according to different treatment strategies: (a) asymptomatic at ED arrival and treated empirically (n=134); (b) asymptomatic at ED arrival, but treatment withheld until symptoms appeared (n=106; 6 of the 106 received North American Coral Snake Antivenin (Equine) at some point; the remainder were never treated); (c) symptomatic at ED arrival and treated with North American Coral Snake Antivenin (Equine) (n=112); and (d) symptomatic at ED arrival but not treated with North American Coral Snake Antivenin (Equine) (n=35). The average number of vials administered to treated patients was 3.75 (range 1 – 20 vials); the 17 patients who received repeat treatment were administered 8.3 vials, on average. There was no reported usage of foreign antivenom or acetylcholinesterase inhibitors in this case series. The 387 patients were assessed for clinical outcomes, as shown in Table 1. Outcomes codes range from full recovery with no residual effects ("No Effect") to less than full recovery with significant residual effects ("Major"). Empiric treatment of asymptomatic patients resulted in more 'moderate' and 'major' outcomes compared to withholding treatment until symptoms appeared (p<.001), however, the patients were not randomized and selection biases could have affected this result.

Adverse reactions associated with North American Coral Snake Antivenin (Equine) administration were documented in 46 (18.25%) cases. The most common adverse reactions were hives, rash and/or welts (12%); itching (9%); shortness of breath (8%); hypotension (2%) and angioedema (1%). Antihistamines were administered to 46 patients, corticosteroids to 40, and epinephrine to 10 cases to treat these adverse reactions.

1. 1.Bowden, C and Krenzelok, E: Clinical applications of commonly used contemporary antidotes, a US perspective. Drug Safety 1997; 16(1):9-47.
2. 2.Sasaki, J et al: Coral snake bites and envenomation in children, A case series. Ped Emerg Care 2014; 30(4):262-5.
3. 3.Wood A, Schauben J, Thundiyil J, et al. Review of Eastern coral snake (Micrurus fulvius fulvius) exposures managed by the Florida Poison Information Center Network: 1998-2010. Clin Toxicol 2013; 51(8):783-8.

North American Coral Snake Antivenin (Equine) is supplied as a sterile lyophilized powder in single use vial (NDC 0008-0423-01) in a carton (NDC 0008-0423-03).

Advise patients to contact the physician or emergency department immediately if they experience any signs and symptoms of delayed allergic reactions or serum sickness up to 14 days following hospital discharge. Symptoms include rash, pruritus, joint pain, arthralgia, fever, lymphadenopathy, and malaise.

U.S. Govt. License No. 3

This product's label may have been updated. For current full prescribing information, please visit www.pfizer.com.

LAB-0726-7.0

NDC 0008-0423-01

North American
Coral Snake
Antivenin
(Equine)
10 mL

Lyophilized Powder for Solution
for Intravenous Injection

Rx only

NDC 0008-0423-03
Contains 1 of NDC 0008-0423-01

North American
Coral Snake
Antivenin
(Equine)
10 mL

Lyophilized Powder for Solution
for Intravenous Injection

This package contains one vial of
lyophilized Antivenin (Micrurus fulvius)
with 0.25% phenol as a preservative
(before lyophilization).
Sealed under partial vacuum.

Pfizer Injectables

Rx only