Comparative anticonvulsant activity of 4-chlorobenzenesulfonamide and prototype antiepileptic drugs in rodents.

The anticonvulsant and toxic properties of 4-chlorobenzenesulfonamide (ADD 55051) were compared with phenytoin (PHT), phenobarbital (PB), ethosuximide (ESM), and valproate (VPA). These compounds were evaluated in mice and rats using well-standardized anti-convulsant test procedures. The results indicate that ADD 55051 is a very effective anticonvulsant in the maximal electroshock seizure (MES) model in mice after either intraperitoneal (i.p.) or oral administration and in rats after oral administration. In mice treated i.p. or orally, ADD 55051 was also effective in preventing seizures induced by pentylenetetrazol (PTZ). The toxicity of ADD 55051 after oral administration was quite low, yielding high TD50 values in both mice and rats and producing a very high protective index (PI = TD50/ED50) in both species as compared with the prototype antiepileptic drugs (AEDs).