A useful property of the many benzodiazepine site allosteric modulators is that they may display selective binding to particular subsets of receptors comprising specific subunits. This allows one to determine which GABA A receptor subunit combinations are prevalent in particular brain areas and provides a clue as to which subunit combinations may be responsible for behavioral effects of drugs acting at GABA A receptors. These selective ligands may have pharmacological advantages in that they may allow dissociation of desired therapeutic effects from undesirable side effects.  Few subtype selective ligands have gone into clinical use as yet, with the exception of zolpidem which is reasonably selective for α 1 , but several more selective compounds are in development such as the α 3 -selective drug adipiplon . There are many examples of subtype-selective compounds which are widely used in scientific research, including:
Synthetic tetrahydrocannabinol (THC) is prescribed under the INN dronabinol or the brand name Marinol , to treat vomiting and for enhancement of appetite , mainly in people with AIDS as well as for refractory nausea and vomiting in people undergoing chemotherapy .  THC is also an active ingredient in nabiximols , a specific extract of Cannabis that was approved as a botanical drug in the United Kingdom in 2010 as a mouth spray for people with multiple sclerosis to alleviate neuropathic pain , spasticity , overactive bladder , and other symptoms.