[Development of new antiepileptics. V. Pharmacological activity of some derivatives of sulfanilamide (author's transl)].

9 derivatives of sulfanilamide were tested for anticonvulsant properties against electroconvulsive shock in mice and rats and against pentylenetetrazole shock in mice. Reference standard in these tests was sulfanilamide. Their toxic, analgesic and sedative activities were also examined. The anticonvulsive activity of sulfanilamide could be enhanced by substitution of the phenyl ring with a halogen atom. Substitution of the sulfonamide group diminishes the anticonvulsant and increases the sedative activity of sulfanilamide. Detoxication of the basic substance by substitution of the aromatic amino group only little influences the anticonvulsant activity and may even enhance it. Of the tested substances, 1742 (3-chloro-4-phenacetamido-benzene-sulfonamide) exhibited the best anticonvulsant activity; slightly weaker was PB 311 (3-chloro-4-amino-benzene-sulfonamide). The ED50 for the activity against electroconvulsive shock of both substances was about 30 mg/kg p.o. in mice. The relationship between anticonvulsant activity and inhibition of the renal and cerebral carbonic anhydrase is discussed.