O-53 Safety and efficacy of a new anti-venom Fab2 variety in treating Bothrops genus Snakebite Envenomings in French Territories in the Americas: a 12-year retrospective study
Author(s):
D Resiere, J Florentin, H Kallel, R Banydeen, H Mehdaoui, R Neviere
Year of Presentation:
2023
Objective: Snake bites by Bothrops lanceolatus are a typical medical emergency in Martinique (30 cases/year). The
first specific antivenom (Bothrofav®), made in 1993, led
to a reduction in mortality. However, a recent increase in
cases of ischemic stroke induced by envenoming, despite
early serum infusion, suggested a decreasing efficiency.
A new specific antivenom (Bothrofav®) was registered in
February 2011. Clinical use of a de novo F(ab’)2 Bothrofav
preparation (Bothrofav®2) in Martinique restored safety
and complete effectiveness. Almost 76 patients have been
successfully treated with Bothrofav®2 since 2011 without
fatal cases or neurovascular complications. The objective of
this study was to evaluate its safety and efficacy in a prospective series of treated patients.
Methods: Retrospective observational study including all patients admitted due to bites of B. lanceolatus in the three emergency services and medical-surgical ICUs of Martinique from February 2011 to September 2022. Patients were managed according to a protocol established by the Research Group on Snake Bites in Martinique. The intravenous dose of antivenom was adapted to the grade of the bite, defined as a standard score based on clinical and biological criteria. The results were expressed as mean ± SD or %
Results: In 12 years, 316 patients were included (age: 47 ± 17 years, 256M/60W, history: hypertension (3%), HIV (0.9%), diabetes (0.6%)). One chronic renal insufficiency patient was bitten on the arm with the fistula for dialysis. The site was located on the lower (44%) or higher limb (56%). Edema (96%), pain (96%) and, bleeding (70%), elevated troponin (4%) were noted and no patients presented with bleeding disorders. The time between admission and antivenom administration was <3h in 50% of the patients. The outcome was favorable, with no fatalities. Three patients (8%) were operated on because of abscesses at the bite site. One case of thrombosis was observed at the arterio-venous fistula in the patient on dialysis. One patient had an aneurysm of the left tibial artery at the site of the bite, supported in vascular surgery. Systematic venous echo-Doppler of the lower or upper limbs showed no other cases of thrombosis. Initial MRI showed no ischemic injury, particularly in two areas of the posterior inferior cerebral arteries (PICA). The duration of the ICU stay was 1.8 ± 3.0 days.
Conclusion: Our data support the excellent safety and likely effectiveness of early infusion of new anti-venom Bothrofav®2 if bitten by B. lanceolatus in Martinique or B. caribbean in Saint Lucia. Further studies are needed to optimize its dose regimen, especially in the most severe cases.