Convulsant, anticonvulsant and anaesthetic barbiturates. In vivo activities of oxo- and thiobarbiturates related to pentobarbitone.

The convulsant, anticonvulsant and anaesthetic activities of a series of 6 barbiturates related to pentobarbitone have been qualitatively and quantitatively determined in mice. The presence or absence of convulsant activity was strongly dependent on molecular structure and there were marked variations in potency among the convulsant barbiturates. Anticonvulsant and anaesthetic activities were less dependent on structure and even the convulsant barbiturates had some underlying anticonvulsant action. Qualitative activities are also reported for a series of 8 thiobarbiturates. Convulsant activities were reduced in the thiobarbiturates, but some excitant activity remained in the thio analogue of each convulsant oxobarbiturate.