Effects of Anticonvulsants on Local Anaesthetic‐Induced Neurotoxicity in Rats

Abstract

Abstract: The effects of various anticonvulsants on local anaesthetics procaine‐ and lidocaine‐induced convulsions were investigated in rats. Pretreatment with diazepam (2.5–5 mg/kg, intraperitoneally) and clonazepam (5–10 mg/kg, intraperitoneally) completely protected the rats against both local anaesthetic‐induced convulsions. Phenobarbital (12.5–50 mg/kg, subcutaneously) also significantly decreased the incidence of both convulsions and prolonged their latencies. Carbabazepine (10–40 mg/kg, intraperitoneally) did not completely repress both convulsions, but it prolonged their latencies. Phenytoin (5–20 mg/kg, intraperitoneally) and primidone (30–60 mg/kg, intraperitoneally) markedly enhanced both local anaesthetic‐induced convulsions, as shown by shortening of latency and increase in mortality. Valproate (100–200 mg/kg, intraperitoneally) produced a protective effect against procaine‐induced convulsions, while it strongly enhanced lidocaine‐induced convulsions. These results suggest that the benzodiazepines are effective drugs to prevent neurotoxicity induced by local anaesthetics, while phenytoin and primidone potentiate them.