Control of venom-induced tissue injury in copperhead snakebite patients: a post hoc sub-group analysis of a clinical trial comparing F(ab’)₂ to Fab antivenom

Abstract

Introduction

Fab antivenom (FabAV) halts progression of tissue injury and improves recovery in copperhead snakebite. It is unknown if F(ab’)₂AV does as well. The objective of this study was to compare control of tissue injury in copperhead snakebite patients treated with F(ab’)₂AV versus FabAV.

Methods

We performed a post hoc analysis of copperhead envenomated patients in a clinical trial comparing F(ab’)₂AV to FabAV. The outcomes for this analysis are the number of repeat doses required to obtain initial control, the number of patients requiring unscheduled doses during maintenance, and the time from antivenom administration to initial control.

Results

Twenty-one (13 F(ab’)₂AV, 8 FabAV) were copperhead patients. Median age was 46 years with a male predominance. Baseline severity was similar. One (8%) F(ab’)₂AV and 2(25%) FabAV patients required repeat initial dosing, difference = 17%, (95%CI −18, 57%). One (8%) F(ab’)₂AV and 1(13%) FabAV patients required additional doses after maintenance, difference = 5%, (95%CI −27, 45%). Median time to initial control was 2.7 range (2.0, 9.3) hours and 3.5 range (2.0, 7.4) for F(ab’)₂AV and FabAV respectively, difference −0.8 h (95% CI −2.6, 0.9).

Conclusions

This exploratory analysis suggests that the available measures of the control of venom-induced tissue injury are similar between antivenom subgroups.

Keywords:

• Snake bite
• antivenin
• copperhead
• Agkistrodon
• tissue injury

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Correction

Disclosure statement

No funding for this project was received. DEK and MRO report no conflicts of interest.

Correction Statement

This article was originally published with errors, which have now been corrected in the online version. Please see Correction (http://dx.doi.org/10.1080/15563650.2023.2242205)

Additional information

Funding

CJG receives grant funding from BTG Specialty Pharmaceuticals. RCD received research funding from Rare Disease Therapeutics and BTG Specialty Pharmaceuticals.