The relationship between the anticonvulsant properties of SC-13504 and its plasma levels, measured by polarography, in baboons with photosensitive epilepsy.

SC-13504 was given intravenously to baboons with photosensitive epilepsy, Papio papio, with and without prior administration of allylglycine. Plasma levels of the drug were determined by differential pulse polarography and correlated with behavioural changes and the anticonvulsant action of the drug. Protection against photically induced seizures or self-sustaining myoclonic responses was seen 30 to 120 min after SC-13504, 4-8 mg/kg (when plasma levels were 1 mug/ml or greater). EEG and neurological signs of toxicity were seen after SC-13504 8 mg/kg but not after 4-6 mg/kg.