The World Health Organization (WHO) recently added snakebite envenoming to the priority list of Neglected Tropical Diseases (NTD). It is thought that ~75% of mortality following snakebite occurs outside the hospital setting, making the temporal gap between a bite and antivenom administration a major therapeutic challenge. Small molecule therapeutics (SMTs) have been proposed as potential prereferral treatments for snakebite to help address this gap. Herein, we discuss the characteristics, potential uses, and development of SMTs as potential treatments for snakebite envenomation. We focus on SMTs that are secretory phospholipase A2 (sPLA₂) inhibitors with brief exploration of other potential drug targets on venom molecules.

There is a clear, unmet need for effective, lightweight, shelf-stable and economical snakebite envenoming therapies that can be given rapidly after the time of a snake’s bite and as adjuncts to antivenom therapies in the hospital setting. The sPLA2 inhibitor, LY315920, and its orally bioavailable prodrug, LY333013, demonstrate surprising efficacy and have the characteristics of an antidote with potential for both field and hospital use. The efficacy of the active pharmaceutical ingredient (LY315920) and its prodrug (LY333013) to treat experimental, lethal envenoming by Micrurus fulvius (Eastern coral snake) venom was tested using a porcine model. Inhibitors were administered by either intravenous or oral routes at different time intervals after venom injection. In some experiments, antivenom was also administered alone or in conjunction with LY333013. 14 of 14 animals (100%) receiving either LY315920 (intravenous) and/or LY333013 (oral) survived to the 120 h endpoint despite, in some protocols, the presence of severe neurotoxic signs. The study drugs demonstrated the ability to treat, rescue, and re-rescue animals with advanced manifestations of envenoming. Low molecular mass sPLA2 inhibitors were highly effective in preventing lethality following experimental envenoming by M. fulvius. These findings suggest the plausibility of a new therapeutic approach to snakebite envenoming, in this example, for the treatment of a coral snake species for which there are limitations in the availability of effective antivenom.

There is an unmet need for economical snakebite therapies with long shelf lives that are effective even with delays in treatment. The orally bioavailable, heat-stable, secretory phospholipase A₂ (sPLA₂) inhibitor, LY333013, demonstrates antidotal characteristics for severe snakebite envenoming in both field and hospital use. A murine model of lethal envenoming by a Papuan taipan (Oxyuranus scutellatus) demonstrates that LY333013, even with delayed oral administration, improves the chances of survival. Furthermore, LY333013 improves the performance of antivenom even after it no longer reverses neurotoxic signs. Our study is the first demonstration that neurotoxicity from presynaptic venom sPLA_2S can be treated successfully, even after the window of therapeutic antivenom has closed. These results suggest that sPLA₂ inhibitors have the potential to reduce death and disability and should be considered for the initial and adjunct treatment of snakebite envenoming. The scope and capacity of the sPLA2 inhibitors ability to achieve these endpoints requires further investigation and development efforts.

The cost-effectiveness of the standard of care for snakebite treatment, antivenom, and supportive care has been established in various settings. In this study, based on data from South Indian private health-care providers, we address an additional question: “For what cost and effectiveness values would adding adjunct-based treatment strategies to the standard of care for venomous snakebites be cost-effective?” We modeled the cost and performance of potential interventions (e.g., pharmacologic or preventive) used adjunctively with antivenom and supportive care for the treatment of snakebite. Because these potential interventions are theoretical, we used a threshold cost-effectiveness approach to explore this forward-looking concept. We examined economic parameters at which these interventions could be cost-effective or even cost saving. A threshold analysis was used to examine the addition of new interventions to the standard of care. Incremental cost-effectiveness ratios were used to compare treatment strategies. One-way, scenario, and probabilistic sensitivity analyses were conducted to analyze parameter uncertainty and define cost and effectiveness thresholds. Our results suggest that even a 3% reduction in severe cases due to an adjunct strategy is likely to reduce the cost of overall treatment and have the greatest impact on cost-effectiveness. In this model, for example, an investment of $10 of intervention that reduces the incidence of severe cases by 3%, even without changing antivenom usage patterns, creates cost savings of $75 per individual. These findings illustrate the striking degree to which an adjunct intervention could improve patient outcomes and be cost-effective or even cost saving.

Introduction: In Eswatini in Southern Africa, rural populations experience unnecessary snakebite-inflicted injuries and deaths. Children are at the highest risk because of their small size and curious nature. This qualitative study explores the current knowledge and attitudes about snakebite, and the perceptions of a musical intervention, titled kulo ngenyoka ('Snake song' in Zulu), as an educational tool aimed to raise awareness about snakes in the Lubombo region, Eswatini. Methods: Semi-structured interviews with community members (n=56), parents/guardians/key informant (n=11) and children aged 7-17 years (n=45) were conducted between May and June 2018.Participants were selected from four communities within the Lubombo region. Data were analyzed using a framework analysis approach. Results: The current sources of snake education evolved from information learned in the homesteads, schools, and through personal experiences. The majority of interviewees perceived music as a culturally appropriate, engaging and memorable method to learn about snakes. Iculo ngenyoka was perceived as an effective tool to raise awareness about snakes in the community. Conclusion: This study is the first to explore the importance of musical interventions in educating vulnerable communities about snakes. The Iculo ngenyoka song offers a portable medium for communicating messages about snakebite prevention, affirming the value of snakebite awareness and promoting cooperative efforts to address the burden of snakebite envenoming in the region. The results emphasize the demand for education and the potential use of Iculo ngenyoka and similar musical tools to raise awareness about snakebite in Eswatini. Re-translation and other customizations of structured musical education tools for children could be applied broadly if shown to be effective.