Centrally acting muscle relaxants in tetanus.

The anti-tetanus activity of a number of phenothiazine derivatives and other centrally acting muscle relaxants, such as mephenesin, dicyclopropyl ketoxime, 2-amino-6-methylbenzothiazole and meprobamate, has been determined in rabbits with experimental local tetanus. Structure-activity relationships were obtained for the phenothiazine derivatives and their anti-tetanus activity correlated with other central and peripheral properties. Both dicyclopropyl ketoxime and 2-amino-6-methyl-benzothiazole were twice as active as mephenesin. Meprobamate does not appear to be primarily a muscle relaxant of the mephenesin type.