Effects of anticonvulsants on acute cypermethrin poisoning in mice and rats

Male albino mice were given 35 mg cypermethrin/kg bw followed immediately b y 1.0, 2.5 or 5 mg diazepam/kg, 5, 10 or 20 mg phenobarbitone/kg, or 10, 25 or 50 mg diphenylhydantoin/kg ip in dose groups of 10 m ice each. Effectiv eness of therapy was assessed by alleviation of effects and survival percen tage. Rat brains implanted withelectroencephalographic (EEG) and electromyo grahic electrodes were given 58 mg cypermethrin/kg followed by 5 mg diazepa m/kg, 20 mg phenobarbitone/kg, or 50 mg diphenylhydantoin/kg. Diazepam at 5 mg or 20 mg phenobarbitone/kg produced 100% survival and alleviated all th e signs of poisoning while diphenylhydantoin produced 80% survival at 50 mg /kg. The antidotes antagonised desynchronization of EEG waves produced in r ats exposed to cypermethrin. These results suggest involvement of GABA in t he mechanism of cypermethrin action in addition to its established effect o n the sodium ion channel.