Lodaxaprine is a chemically original compound which possesses the pharmacological properties of a potent, p.o. active anticonvulsant. In mice, lodaxaprine antagonized electroconvulsive shock and chemically induced seizures with an overall potency comparable to that of carbamazepine. In naturally photosensitive Senegalese Papio-papio baboons lodaxaprine antagonized myoclonus and cortical paroxysmal discharges. In this model lodaxaprine was approximately one-fourth as potent as phenobarbital, twice as potent as carbamazepine and 6 times more potent than sodium valproate. Lodaxaprine had been in phase II clinical trial for the treatment of epilepsy. However, this development was discontinued.