Adipiplon

Adipiplon (NG2-73) is an anxiolytic drug developed by Neurogen Corporation. It has similar effects to benzodiazepine drugs, but is structurally distinct and so is classed as a nonbenzodiazepine anxiolytic.

Adipiplon is a subtype-selective GABA_A receptor partial agonist, which binds preferentially to the α₃ subtype. This is significant as while several previous nonbenzodiazepine drugs have been developed that are selective for α_2/3 over the other subtypes, adipiplon is one of the first drugs selected for clinical development which is able to discriminate between α₂ and α₃, as well as showing little affinity for the α₁ or α₅ subtypes - alpidem is selective for α₃ over α₂, but still has moderate affinity for α₁, whereas adipiplon is highly α₃-selective with little affinity for either α₁, α₂ or α₅.

Adipiplon is being researched as a potential medication for the treatment of anxiety and insomnia, and is currently (as of 2008) in Phase IIb trials.