Like benzodiazepines, Z drugs target the benzodiazepine subtype of the GABA-a receptor complex, exerting a braking effect on excitatory neuro-transmission and leading to a calming affect on a given portion of the brain.
Limited information exists as to the development of tolerance, dependence, and long term effects of nonbenzodiazepines compared to benzodiazepines. However, one can assume they are similar in these respects.
The first to appear were zopiclone, zolpidem, and zaleplon; all three are used as sleep aids.
Side effects are similar to benzodiazepines and include hypnosis, anterograde amnesia, skeletal muscle relaxation, depression, ataxia and cognitive impairment.
Recent research & development has focused on a class of nonbenzodiazepine derivatives for anxiolytic use. These compounds possess anti-anxiety properties of the benzodiazepines and nonbenzodiazepines but produce little to no hypnosis or intoxication at therapeutic doses. For instance, pagoclone binds with benzodiazepine receptors with extreme selectivity, targeting the GABA a2 and a3 subtype without affecting the a1 subtype - the a2 and a3 subtypes mediate the anxiolytic effects of benzodiazepine-type drugs, while the a1 subtype mediates sedation & memory loss.
|Benzodiazepine structure (far right) VS Nonbenzodiazepine structure (first 3 on the left)|
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