February 10, 2016
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"Below is a list of the most popular prescription drugs dispensed in 2011 with links to drug monographs. The list may include the medication brand name and generic name.

Note: This information pertains to U.S. prescriptions only./"...



How Supplied


CroFab® is indicated for the management of patients with North American crotalid envenomation (see Table 5 in Clinical Studies section for definitions). The term crotalid is used to describe the Crotalinae subfamily (formerly known as Crotalidae) of venomous snakes which includes rattlesnakes, copperheads and cottonmouths/water moccasins. Early use of CroFab® (within 6 hours of snakebite) is advised to prevent clinical deterioration and the occurrence of systemic coagulation abnormalities.


For Intravenous Use after Reconstitution


  • Antivenin dosage requirements are contingent upon an individual patient's response; however, based on clinical experience with CroFab®, the recommended initial dose is 4 to 6 vials.
  • Administration of antivenin should be initiated as soon as possible after crotalid snakebite in patients who develop signs of progressive envenomation (e.g., worsening local injury, coagulation abnormality, or systemic signs of envenomation). CroFab® was shown in the clinical studies to be effective when given within 6 hours of snakebite.
  • The patient should be observed for up to 1 hour following the completion of this first dose to determine if initial control of the envenomation has been achieved (as defined by complete arrest of local manifestations, and return of coagulation tests and systemic signs to normal). If initial control is not achieved by the first dose, an additional dose of 4 to 6 vials should be repeated until initial control of the envenomation syndrome has been achieved.
  • After initial control has been established, additional 2-vial doses of CroFab® every 6 hours for up to 18 hours (3 doses) is recommended. Optimal dosing following the 18-hour scheduled dose of CroFab® has not been determined. Additional 2-vial doses may be administered as deemed necessary by the treating physician, based on the patient's clinical course.
  • Additional Patient Care (Supportive and Adjunctive Therapy): Supportive measures are often utilized to treat certain manifestations of crotalid snake envenomation, such as pain, swelling, hypotension, and wound infection. Poison control centers are a helpful resource for individual treatment advice.

Preparation And Administration

  • Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.
  • Each vial of CroFab® should be reconstituted with 18 mL of 0.9% Saline (diluent not included) and mixed by continuous manual inversion until no solid material is visible in the vial. Do not shake. The contents of all of the reconstituted vials should be further diluted in 250 mL of 0.9% Sodium Chloride USP and mixed by gently swirling.
  • The initial dose of CroFab® diluted in 250 mL of saline should be infused intravenously over 60 minutes. However, the infusion should proceed slowly over the first 10 minutes at a 25- 50 mL/hour rate with careful observation for any allergic reaction. If no such reaction occurs, the infusion rate may be increased to the full 250 mL/hour rate until completion. Close patient monitoring is necessary.
  • The reconstituted and diluted product should be used within 4 hours.


Dosage Forms And Strengths

CroFab® is supplied as a sterile, nonpyrogenic, purified, lyophilized powder. Each vial contains up to 1 gram of total protein, a maximum of 0.03 mg of mercury, and not less than the indicated number of mouse LD50 neutralizing units*:

Snake Species Used for Antivenin Component Minimum mouse LD50 Units per vial
C. atrox (Western Diamondback rattlesnake) 1270
C. adamanteus (Eastern Diamondback rattlesnake) 420
C. scutulatus (Mojave rattlesnake) 5570
A. piscivorus (Cottonmouth or Water Moccasin) 780
* As of 2008, the potency assay has been optimized for a new strain of mice, which has resulted in changes to the minimum mouse LD50 neutralizing units. These changes do not reflect any change in product potency, but only a different biological response of the mouse strain to the venom.

Storage And Handling

CroFab® is supplied as a carton that contains 2 vials of product (diluent not included). Each vial of CroFab® contains up to 1 gram of lyophilized total protein and not less than the indicated number of mouse LD50 neutralizing units:

Snake Species Used for Antivenin Component Minimum mouse LD50 Units per vial
C. atrox (Western Diamondback rattlesnake) 1270
C. adamanteus (Eastern Diamondback rattlesnake) 420
C. scutulatus (Mojave rattlesnake) 5570
A. piscivorus (Cottonmouth or Water Moccasin) 780

NDC 50633-110-12

  • Store at 2° to 8°C (36° to 46°F).
  • Do not freeze.
  • Use within 4 hours after reconstitution.


6. Quarre JP, Lecomte J, Lauwers D, Gilbert P, Thiriaux J. Allergy to latex and papain. J Allergy Clin Immunol 1995; 95(4):922.

7. Baur X, Chen Z, Rozynek P, Düser D, Raulf Heimsoth M. Cross reacting IgE antibodies recognizing latex allergens, including Hev b 1, as well as papain. Allergy 1995; 50(7):604 609.

Manufactured for: and distributed by: BTG International Inc., West Conshohocken, PA 19428. Revised March 2012

This monograph has been modified to include the generic and brand name in many instances.

Last reviewed on RxList: 4/17/2015

How Supplied

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