Use of snake antivenom in the Region of the Americas: a systematic review

To evaluate the use of antivenom therapy in Bothrops envenomation in the Region of the Americas and to synthesize data on treatment outcomes, adverse reactions and long-term sequelae.

We systematically searched Web of Science, Scopus, Lilacs, PubMed® and Google Scholar for studies published up to 5 May 2025 that reported on the effects of antivenom treatment in humans bitten by Bothrops species in the Region of the Americas. We extracted data on patient demographics, adverse reactions, clinical complications and long-term sequelae following antivenom therapy.

Of 2060 articles identified, 38 met the inclusion criteria. Bothrops envenomations occurred more frequently in men (75.2%; 3247/4320 individuals), predominantly affected the lower limbs (76.5%; 2494/3295) and typically resulted in moderate-grade envenoming (44.6%; 1553/3483 individuals). We found that adverse reactions to antivenom therapy were common: 19.6% (589/2998) experienced early reactions and 1.6% (16/992) delayed reactions, although incidence declined in recent years. Individuals experienced clinical complications, such as severe oedema (23.2%; 239/1032), secondary infections (22.8%; 452/1985) and coagulopathies (20.7%; 357/1724). Some patients also experienced permanent sequelae, though these complications were relatively infrequent (3.3%; 50/1512). For studies reporting on deaths, 0.8% (23/3035) of patients died.

Antivenom therapy remains central to the management of Bothrops envenomation. However, challenges persist in treatment outcomes and long-term sequelae. Addressing these challenges requires ongoing research to strengthen antivenom manufacturing, explore adjunct therapies and improve post-envenomation care. Substantial heterogeneity study methods and reported outcomes, precluded the ability to conduct pooled analyses and generalize findings.