Effect of cinromide on inhibitory and excitatory mechanisms.

The effect of the experimental anticonvulsant cinromide (3-bromo-N-ethylcinnamamide) on various inhibitory and excitatory mechanisms was investigated in the trigeminal nucleus of cats. Intravenous administration of 20-80 mg/kg cinromide depressed excitatory transmission and facilitated segmental inhibition to the same extent as phenytoin, but less than carbamazepine. These doses of cinromide also depressed periventricular inhibition, similar to valproate and ethosuximide. In addition, cinromide had a marked depressant effect on the EEG, suggesting a pronounced sedative effect. The serum levels of cinromide and of its active metabolites (3-bromocinnamamide and 3-bromocinnamic acid) were comparable to those in patients receiving long-term treatment with cinromide. Our results agree with those in other experimental models, which also suggest that cinromide is a broad-spectrum anticonvulsant, and with cinromide's effect in the clinical trials reported so far.