Antagonism Between Alkylated and Norcompounds of the Morphine Group Injected Intracisternally into Mice

Abstract

Abstract The analgesia which resulted from the intracisternal injection of mixtures of morphine and normorphine in mice developed more slowly than, and finally equalled but did not exceed that of the more active component of the mixture. Pethidine and morphine antagonised normorphine similarly. However, the analgesia which followed the intracisternal injection of mixtures of pethidine and norpethidine developed as rapidly but was less intense than that due to either single component of the mixtures.