Routine Antibiotic vs. Directed Antibiotic Treatment in Snake Bite

Snake bite is a common clinical problem in India and elsewhere, affecting agricultural workers and rural population, resulting in thousands of deaths every year. Apart from causing systemic manifestations such as coagulopathy, acute renal failure, and neuroparalysis, local effects of the venom manifest as swelling of the bitten limb. Despite administration of adequate antivenom, the limb swelling progresses in the first 48-72 hours accompanied by considerable pain. Often the limb swelling is accompanied by formation of blebs and gangrenous skin changes. At times, the limb swelling is severe enough to result in compartment syndrome, necessitating surgical interventions such as fasciotomy and debridement. Animal bites are typically associated with a risk of infection by the oral flora. Likewise, apart from releasing the venom, inoculation of oral flora as a result of snake bite could result in local infectious complications adding to the deleterious effects of the snake venom. Observational studies suggest that the risk of infection following simple bites on the lower limbs is much less than what is often believed, and evidence from clinical trials also does not support routine use of antibiotics in snake bite. For this reason, clinical practice guidelines do not recommend routine prophylactic use of antibiotics in snake bite. But, in reality, many clinicians continue to use antibiotics routinely in all venomous snake bites hoping to prevent a local infection. While such a strategy may not reduce the risk of infection, it would result in overuse of antibiotics promoting antimicrobial resistance and escalating treatment costs. The investigators hypothesize that clinically-directed use of antibiotics would be non-inferior to routine use in preventing local infectious complications of snake bite, while being superior in reducing the antibiotic consumption. Non-inferiority would be inferred if the one-sided 95% CI of the difference does not exceed 10% in favour of the routine use arm.