For Intravenous use only.
Administer ANAVIP as soon as possible after rattlesnake bite in patients who develop any signs of envenomation (e.g., local injury, coagulation abnormality, or systemic signs of envenomation). Sections or subsections omitted from the full prescribing information are not listed.
The amount of antivenin required to treat a snake bitten patient is highly variable owing in part to the venom burden, the potency of the venom and the time to health care presentation. Use supportive measures to treat certain manifestations of rattlesnake envenomation, such as pain, swelling, hypotension, and wound infection. Contact the local poison control centers for additional individual treatment advice.
Prior to initiating treatment perform laboratory analyses, including complete blood count, platelet count, PT, PTT, serum fibrinogen level and routine serum chemistries. Repeat testing at regular intervals to gauge response to therapy and anticipate additional dosing.
Initial Dose: 10 vials
- The initial dose of ANAVIP is 10 vials.
- Reconstitute the contents of each vial with 10 milliliters (mL) of sterile normal saline (0.9% NaCl). Average reconstitution time is 11.8 seconds (range 8-26 seconds) per vial when using continuous gentle swirling.
- Inspect the solution visually for particulate matter and discoloration prior to administration. The solution is expected to be clear to yellow/green and opalescent. Do not use if otherwise discolored or turbid.
- Combine the contents of the reconstituted vials promptly and further dilute to a total volume of 250 mL with sterile normal saline (0.9% NaCl). Fluid volumes may need to be adjusted for very small children or infants. Poison Control Centers are a helpful resource for individual treatment advice.
- Infuse intravenously over 60 minutes.
- For the first 10 minutes infuse at a 25-50 mL/hour rate, carefully monitoring for any allergic reactions, including any anaphylactic reactions. Discontinue the infusion if any allergic reaction occurs and institute appropriate emergency treatment. Reassess the risk to benefit before continuing the infusion.
- If no reactions occur, the infusion rate may be increased to the full 250 mL/hour rate until completion. If there is any allergic reaction at any time, stop the infusion, treat accordingly, and reassess the need to continue ANAVIP.
- Following the completion of infusion, monitor the patient for at least 60 minutes for any allergic reaction and to determine that local signs of envenomation are not progressing (leading edge of local injury not progressing), systemic symptoms are resolved and coagulation parameters have normalized or are trending toward normal.
- Use reconstituted and diluted product within 6 hours.
- Discard partially or unused reconstituted and diluted product.
Additional Dosing to Achieve Initial Control
- Administer additional 10 vial doses if needed to arrest the progressive symptoms and repeat every hour. There is no known maximum dose.
- Repeat above steps for initial dose as many times as needed until local signs of envenomation are not progressing, systemic symptoms are resolved and coagulation parameters have normalized or are trending toward normal.
- Prepare as described above for initial dose.
- Once initial control has been achieved, observe the patient to determine any need for further dosing, as described below.
Observation and late Dosing
- Monitor patients in a health care setting at least 18 hours following initial control of signs and symptoms. Re-emerging symptoms including coagulopathies may be suppressed with additional 4 vial doses of ANAVIP as needed. Reconstitute each vial with 10 mL of sterile normal saline (0.9% NaCl). Combine and further dilute to a total of 250 mL. Infuse intravenously over 60 minutes.
