A Single-Center Review of Cases to Understand the Indian Polyvalent Antivenom Use in Hump-Nosed Pit Viper Bites in South India.

Abstract

Introduction: India, with nearly 60 venomous snake species, has just one commercially available antivenom, the Indian polyvalent antivenom (IPAV). The hump-nosed pit viper (Hypnale hypnale), an indigenous venomous snake, causes considerable morbidity and at time mortality for which we have no commercially available antivenom. However, most clinicians rely purely on the clinical syndromes and end up using the available IPAV for H. hypnale envenomation.

Methods: Between April 2017 and December 2022, we reviewed 41 cases of H. hypnale envenomation, comparing clinical and laboratory profiles of patients who received IPAV with those who did not.

Results: Local signs of envenomation were seen in 39 (95.12%) cases, with the most common being edema or swelling at the bite site. Eight (19.5%) patients developed coagulopathy, and two developed renal failure during their hospital stay. Among the 39 envenomated individuals, 13 received polyvalent snake antivenom. Over half of those receiving antivenom had hypersensitivity reactions. Patients who received antisnake venom (ASV) had increased intensive care unit stay, duration of hospitalization, and hospital expenses as compared to patients who did not. There was one death among the patients who received antivenom.

Conclusion: H. hypnale viper envenomation is associated with local and systemic signs of envenomation, with coagulopathy being a common complication. Administering the current polyvalent antivenom to victims of H. hypnale bites did not reduce the morbidities or prevent mortality; instead, it exposes them to additional risks associated with ASV administration.