Effectiveness of anticonvulsants in mice exposed to mixed gamma-neutron radiations

The effectiveness of four anticonvulsants was tested in male CF1 mice exposed to 500-, 1000-, and 10,000-rad doses of mixed gamma-neutron radiations. Prevention of the hind leg extensor component of a maximal convulsion induced by electroshock was selected as the end point for effective anticonvulsant activity of diphenylhydantoin, phenobarbital, and mephenytoin. Prevention of convulsions induced by pentylenetetrazol was the end point of effective anticonvulsant activity of trimethadione. The effectiveness of the drugs was evaluated by comparing the ED50's to the ED50 value for unirradiated controls. The anticonvulsants tested by electroshock showed a tendency toward increasing effectiveness after 500- and 1000-rad doses of radiation and a significantly increased effectiveness following 10,000 rads. Trimethadione effectiveness in irradiated mice was similar to that in unirradiated controls at all doses and times tested.