Opposed to diazepam, zolpidem is able to bind to binary αβ GABA receptors, where it was shown to bind to the α1–α1 subunit interface. Zolpidem has about 10-fold lower affinity for the α2- and α3- subunits than for α1, and no appreciable affinity for α5 subunit-containing receptors. ω1 type GABAA receptors are the α1-containing GABAA receptors and are found primarily in the brain, the ω2 receptors are those that contain the α2-, α3-, α4-, α5-, or α6 subunits, and are found primarily in the spine. Thus, zolpidem favours binding to GABAA receptors located in the brain rather than the spine. Zolpidem has no affinity for γ1 and γ3 subunit-containing receptors and, like the vast majority of benzodiazepine-like drugs, it lacks affinity for receptors containing α4 and α6. Zolpidem modulates the receptor presumably by inducing a receptor conformation that enables an increased binding strength of the orthosteric agonist GABA towards its cognate receptor without affecting desensitization or peak currents.Like zaleplon, zolpidem may increase slow wave sleep but cause no effect on stage 2 sleep. A meta-analysis that compared benzodiazepines against nonbenzodiazepines has shown few consistent differences between zolpidem and benzodiazepines in terms of sleep onset latency, total sleep duration, number of awakenings, quality of sleep, adverse events, tolerance, rebound insomnia, and daytime alertness. Pharmokinetics
Microsome studies indicate zolpidem is metabolized by CYP3A4 (61%) CYP2C9 (22%), CYP1A2 (14%), CYP2D6 (<3%), and CYP2C19 (<3%). It is principally metabolized into three metabolites, none of which are believed to be pharmocologically active. The absolute bioavailability of zolpidem is about 70%.
Zolpidem can typically be detected in bodily fluids for 36 hours, though it may be possible to detect it by hair testing much later, which is due to the short elimination half-life of 2.5–3 hours. This use of the drug was highlighted during proceedings against Darren Sharper, who was accused of using the tablets he was prescribed to facilitate a series of rapes. Sleepwalking
Zolpidem received widespread media coverage in Australia after the death of a student who fell 20 metres (66 ft) from the Sydney Harbour Bridge while under the influence of zolpidem. Brands
As of September 2018, zolpidem was marketed under many brands: Adorma, Albapax, Ambien, Atrimon, Belbien, Bikalm, Cymerion, Dactive, Dalparan, Damixan, Dormeben, Dormilam, Dormilan, Dormizol, Eanox, Edluar, Flazinil, Fulsadem, Hypnogen, Hypnonorm, Intermezzo, Inzofresh, Ivadal, Ivedal, Le Tan, Lioram, Lunata, Medploz, Mondeal, Myslee, Nasen, Niterest, Nocte, Nottem, Noxidem, Noxizol, Nuo Bin, Nytamel, Nyxe, Olpitric, Onirex, Opsycon, Patz, Polsen, Sanval, Semi-Nax, Sleepman, Somex, Somidem, Somit, Somnil, Somnipax, Somnipron, Somno, Somnogen, Somnor, Sonirem, Sove, Soza, Stilnoct, Stilnox, Stilpidem, Stimin, Sublinox, Sucedal, Sumenan, Vicknox, Viradex, Xentic, Zasan, Zaviana, Ziohex, Zipsoon, Zodem, Zodenox, Zodium, Zodorm, Zolcent, Zoldem, Zoldorm, Zoldox, Zolep, Zolfresh, Zolip, Zolman, Zolmia, Zolnox, Zolnoxs, Zolodorm, Zolnyt, Zolpeduar, Zolpel, Zolpi, Zolpi-Q, Zolpic, Zolpidem, Zolpidem tartrate, Zolpidemi tartras, Zolpidemtartraat, Zolpidemtartrat, Zolpidemum, Zolpigen, Zolpihexal, Zolpimist, Zolpineo, Zolpinox, Zolpirest, Zolpistar, Zolpitop, Zolpitrac, Zolpium, Zolprem, Zolsana, Zolta, Zoltar, Zolway, Zomnia, Zonadin, Zonoct, Zopid, Zopidem, Zopim, and Zorimin. Research
While cases of zolpidem improving aphasia in people with stroke have been described, use for this purpose has unclear benefit.