RECENT ADVANCES IN BENZODIAZEPINE PHARMACOLOGY

Abstract

A summary has been presented of recent developments in the field of benzodiazepine pharmacology. Details were presented of the interactions between two types of compounds which antagonise the effects of benzodiazepines, the β-carbolines and imidazodiazepine Ro 15-1788. The β-carbolines produce pharmacological effects which are opposite to those of the benzodiazepines, as they lower seizure threshold, have anxiogenic activity and decrease the effects of γ-aminobutyric acid (GABA). Ro 15-1788 prevents the effects of the benzodiazepines at doses which have no overt pharmacological effects, although there is evidence that it has weak partial agonist activity. It has been found that Ro 15-1788 also prevents the effects of the β-carbolines, both in vivo and in vitro and this discovery led to the suggestion that the benzodiazepine receptor may be unusual in that ligands of different types can produce opposite pharmacological effects. The support for this theory is discussed, as is also the possible involvement of benzodiazepine receptor activity in the effects of chronic treatment with benzodiazepines, barbiturates and ethanol.