Table 2: Summary of novel GABAA receptor subtype selective compounds.

TargetNameEfficacy
(compared to a classical benzodiazepine)
Affinity/RemarksRef

α 1ZolpidemComparable at α 1/α 2/α 3/α 55-10-fold higher affinity for α 1 versus α 2/3 > 1000 fold higher affinity for α 1 versus α 5[15]
α 2/3TPA023α 1 (0%), α 2 (11%), α 3 (21%), α 5 (5%)Equivalent affinity [8]
α 2/3TPA123α 1 (23%), α 2 (35%), α 3 (43%), α 5 (19%)Equivalent affinity. Reinforcing efficacy and physiological dependence remained present [8]
α 2/3L838,417α 1 (1.5%), α 2 (43%), α 3 (43%), α 5 (39%)Equivalent affinity [23]
α 2/3SL651498α 1 (45%), α 2 (115%), α 3 (83%), α 5 (50%)
Compared to zolpidem for α 1 efficacy
5–10-fold increased affinity for α 2/3, 10–20 fold lower affinity for α 5 [31]