Total CroFab and Anavip Antivenom Vial Administration in US Rattlesnake Envenomations: 2019-2021

Area of Science:

• * Toxicology
• * Pharmacology
• * Emergency Medicine

Background:

• * Anavip and CroFab are antivenoms for rattlesnake envenomations in the USA.
• * Limited comparative data exists on their real-world usage characteristics.
• * This study addresses the need for comparative treatment analysis.

Purpose of the Study:

• * To compare the number of antivenom vials administered for CroFab versus Anavip.
• * To analyze differences in treatment characteristics between the two antivenoms.
• * To evaluate antivenom efficacy in treating rattlesnake envenomations.

Main Methods:

• * Secondary analysis of rattlesnake envenomation cases from the North American Snakebite Registry (2019-2021).
• * Comparison of total antivenom vials administered as the primary outcome.
• * Secondary outcomes included administration events, treatment duration, and hospital stay.

Main Results:

• * 291 envenomations analyzed; 96% in the Western USA.
• * CroFab: 10 vials median; Anavip: 18 vials median; Both: 20 vials median.
• * Anavip required more administrations (69%) than CroFab (39%) for single-product treatment.

Conclusions:

• * CroFab-treated patients used fewer antivenom vials compared to Anavip.
• * Fewer antivenom administrations were needed with CroFab.
• * Findings suggest differences in treatment requirements between CroFab and Anavip for rattlesnake bites.