The new algorithm for calculation of median lethal dose (LD50) and effective dose fifty (ED50) of Micrarus fulvius venom and anti-venom in mice

Abstract

One million people throughout the world are bitten yearly by poisonous snakes. Of this, one-tenth died and three-tenth suffer some forms of disabilities. In view of this, anti-snake venoms are currently being developed against viper and colubrid snake venoms using mice. Therefore, a new algorithm for calculation of median lethal dose (LD50) and effective dose fifty (ED50) was developed for Micrarus fulvius venom and antivenom respectively. This paper compared the formula of effective dose fifty (ED50) developed by Spearman and Karber with ideal median lethal dose (IMLD50) formula developed by Saganuwan with a view to bringing out their difference and similarity in calculation of ED50 that could be used to develop a new median lethal dose formula for calculation of Micrarus fulvius venom in mice. The findings revealed that ED50 value (477mg/kg) from Spearman and Karber’s formula (ED50=logED50=logX100-logFDn(Σt-n/2) is comparatively similar with ideal median lethal dose value (428.75mg/kg) from Saganuwan’s formula (MLD50+MSD50/2). The new LD50 formula (LD50=ED503×Wm×10-4) yielded value (0.29mg/kg) of comparative significance with reported value (0.32mg/kg). When ED50 is equal to 2LD50, the denominator of ED503 becomes 2. In conclusion, the new formula would yield low doses of snake anti-venoms with reduced possibility of hypersensitivity reaction.