Snake Envenomation

Snakebite is a severe problem for tropical and subtropical countries, India included. This country is the home of many species of venomous and non-venomous snakes; however, the majority of the serious incidences of snakebite in India are due to the “Big Four” venomous snakes: Indian Spectacled Cobra ( Naja naja ), Common Krait ( Bungarus caeruleus ), Russell’s Viper ( Daboia russelii ) and Saw-scaled Viper (Echis carinatus ). Nevertheless, the medical significance of other species of venomous snakes is not well recognized. Snake venom is a mixture of enzymatic and non-enzymatic proteins and polypeptides, and it exerts a wide array of patho-physiological and pharmacological effects on prey and victims. Recently, proteomic analysis has shown the occurrence of several unique and common toxins in the same species of snakes but from different locales. This disparity of venom composition is associated with different clinical manifestations post envenomation. Due to the lack of venom detection kits, administration of polyvalent antivenom raised against the venoms of the “Big Four” snakes is the only choice for treatment in India. However, this therapy is associated with several adverse reactions that are not well documented in India. Further, the number of vials of antivenom to be administered to a snakebite patient is also dependent on the experience of the treating physician. The greatest difficulties have been associated with treating Russell’s Viper bites, followed by krait bites and then cobra bites patients; surprisingly, it is relatively easy to treat saw-scaled viper bite patients. Intubation and mechanical ventilation are often necessary in the management of neurotoxic snakebites (krait and cobra). Several impediments to the successful treatment of snakebite in India are identified and elaborated in this chapter, and active involvement of all the sections of society will be required to alleviate this urgent problem.