Crotalidae Immune F(ab′)2 (Equine)
Class: Antitoxins and Immune Globulins
VA Class: IM300
Brands: Anavip
Introduction
Antivenin (antivenom); equine IgG F(ab′)2 fragments capable of binding and neutralizing venom toxins of North American rattlesnakes (pit vipers).
Uses for Crotalidae Immune F(ab′)2 (Equine)
North American Rattlesnake Snakebite Envenomation
Treatment of envenomation following snakebites involving North American rattlesnakes (Crotalinae, crotalines, pit vipers; formerly known as Crotalidae or crotalids). Designated an orphan drug by FDA for this use.
Crotalinae subfamily of venomous snakes includes rattlesnakes, copperheads, and cottonmouths or water moccasins.
Has been effective in management of envenomation involving various crotaline, including Crotalus, Sistrurus, and Agkistrodon.
Consultation with experts experienced in treating snakebites (e.g., regional certified poison control center at 800-222-1222) recommended to guide treatment decisions regarding individual patients.
Crotalidae Immune F(ab′)2 (Equine) Dosage and Administration
General
Initiate treatment as soon as possible after rattlesnake bite in patients who develop clinically important signs of envenomation (e.g., local injury, coagulation abnormality, systemic signs of envenomation).
Prior to and during treatment, assess CBCs, serum chemistries, and coagulation parameters (e.g., PT, aPTT, serum fibrinogen concentration) to evaluate response to the antivenin.
Monitor closely during and for at least 1 hour after IV infusion of the antivenin to assess for allergic reactions and confirm that local signs of envenomation are not progressing, systemic symptoms of envenomation have resolved, and coagulation abnormalities have normalized or are trending towards normalization.
Administration
IV Administration
Administer by IV infusion.
Reconstitution and Dilution
Must be reconstituted and diluted prior to administration.
Reconstitute appropriate number of vials of lyophilized Crotalidae immune F(ab′)2 (equine) by adding 10 mL of 0.9% sodium chloride to each vial; mix using continuous gentle swirling (usually dissolves within 1 minute). Reconstituted solution should be clear to yellow/green and opalescent; do not use if discolored or turbid.
Immediately after reconstitution, combine contents of appropriate number of reconstituted vials and dilute total dose (total combined reconstituted vials) to a total volume of 250 mL using 0.9% sodium chloride. May need to adjust volume of dilution fluid for infants or very small children.
Use reconstituted and diluted antivenin within 4 hours after reconstitution. (See Stability.)
Discard partially used reconstituted vials or unused diluted antivenin.
Rate of Administration
Administer by IV infusion over 60 minutes.
Start initial IV infusion using reduced rate of 25–50 mL/hour for first 10 minutes; observe patient closely for sensitivity reactions (including anaphylaxis). If r...
