barbiturates significantly potentiated the gabaa receptor-induced contractions over the lower dose range of applied gaba ( less than 50 microm ) , without affecting the gabab-receptor-induced 'after-relaxation ' , their relative potencies being thiopentone ( thp ) greater than pentobarbitone ( pb ) greater than barbitone ( bb ) greater than phenobarbitone ( phb ) .
C0004745
barbiturates
C0030883
pentobarbitone