Benzodiazepines

These drugs are mainly used to treat anxiety but are also used to treat certain types of convulsions, depression and to relax individuals. This class of drug was developed to supersede the barbiturates due to the undesirable potential for psychological and physical dependence of the barbiturates. The benzodiazepines act by augmenting the actions of GABA specifically via GABA-A receptors. This is as a result of increased chloride conductance due to the benzodiazepines increasing the affinity for GABA at the receptor (acting allosterically with GABA). This action enhances the inhibitory effects of GABA in the CNS. Long term use can lead to dependence. Their misuse in combination with drugs that also affect the CNS can lead to significant behavioural toxicity. Examples of benzodiazepines include: diazepam, oxazepam, temazepam, nitrazepam, flunitrazepam, clonazepam, alprazolam, etc.

In recent years, other drugs that interact at the same or a related binding of the benzodiazepine receptor, GABA-A have become available which show more selective actions and often have less CNS depressant actions. These drugs that have similar actions to benzodiazepines include buspirone, zopiclone, zolpidem and zaleplon.