The paradoxical effect of lidocaine on an experimental model of epilepsy
Campos, C.J.; Cavalheiro, E.A.
Archives Internationales de Pharmacodynamie et de Therapie 243(1): 66-73
1980
ISSN/ISBN: 0003-9780 PMID: 7387262 Document Number: 157896
The antiepileptic and epileptic effects of lidocaine were studied. The former was studied on an experimental model of epilepsy using low doses of lidocaine hydrochloride (i.m.) and the latter carried out by studying the electrographic epileptic manifestations of large doses (i.p.) of lidocaine hydrochloride. Twisted steel wire electrodes were chronically implanted in the dorsal hippocampus of 20 male albino rats. Cortical electrodes were placed under the frontal bones. One week after surgery the animals received electrical stimulation via the hippocampal electrodes, 1 stimulus/min for 2 h. The animals were injected with saline (i.m.) at the 30th min and with lidocaine at the 60th min. With doses of 15, 30 and 60 mg/kg of lidocaine (i.m.), a significant decrease in the duration of epileptic discharges, elicited by electric stimulation, was observed. The following doses, 15, 30, 75 and 150 mg/kg (i.p.), were given to 30 male albino rats subjected to the same surgical procedure. No electrical stimulation was given. Animals which received i.p. injections of lidocaine (75 mg/kg) showed epileptic electrographical activity. The animals injected with lidocaine (150 mg/kg) showed epileptic electrographical activity and died .apprx. 23 min after the injection. No animal showed any behavioral seizures. A clear anticonvulsant effect of lidocaine with a wide safety margin regarding toxic and lethal levels was observed in the experimental model of epilepsy used.