Clinical data | |
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Trade names | Ambien, others [1] |
AHFS/Drugs.com | Monograph |
MedlinePlus | a693025 |
License data | |
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Dependence liability | Physical: High Psychological: Moderate [3] |
Addiction liability | High [4] |
Routes of administration | By mouth, sublingual, oromucosal (spray), rectal |
Drug class | Nonbenzodiazepine, sedative-hypnotic |
ATC code | |
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Pharmacokinetic data | |
Bioavailability | 70% (by mouth) |
Protein binding | 92% [9] |
Metabolism | Liver through CYP3A4 (~60%), CYP2C9 (~20%), and CYP1A2 (~14%) [10] |
Metabolites | (ZCA) zolpidem 6-carboxylic acid; (ZPCA) zolpidem phenyl-4-carboxylic acid |
Onset of action | ≤ 30 Minutes [11] |
Elimination half-life | 2–3 hours [12] [9] [13] |
Duration of action | 3 hours [14] [15] |
Excretion | Kidney (56%) fecal (34%) |
Identifiers | |
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DrugBank | |
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KEGG | |
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ChEMBL | |
CompTox Dashboard (EPA) | |
ECHA InfoCard | 100.115.604 |
Chemical and physical data | |
Formula | C19H21N3O |
Molar mass | 307.397 g·mol−1 |
3D model (JSmol) | |
Melting point | 193–197 °C (379–387 °F) [9] |
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Zolpidem, sold under the brand name Ambien among others, is a medication primarily used for the short-term treatment of sleeping problems. [12] [16] Guidelines recommend that it be used only after cognitive behavioral therapy for insomnia and after behavioral changes, such as sleep hygiene, have been tried. [17] [18] [19] It decreases the time to sleep onset by about fifteen minutes and at larger doses helps people stay asleep longer. [7] It is taken by mouth and is available in conventional tablets, sublingual tablets, or oral spray. [12]
Common side effects include daytime sleepiness, headache, nausea, and diarrhea. [12] More severe side effects include memory problems and hallucinations. [7] While flumazenil, a GABAA–receptor antagonist, can reverse zolpidem's effects, usually supportive care is all that is recommended in overdose. [20]
Zolpidem is a nonbenzodiazepine, or Z-drug, which acts as a sedative and hypnotic. [12] [20] Zolpidem is a GABAA receptor agonist of the imidazopyridine class. [12] It works by increasing GABA effects in the central nervous system by binding to GABAA receptors at the same location as benzodiazepines. [12] It generally has a half-life of two to three hours. [12] This, however, is increased in those with liver problems. [12]
Zolpidem was approved for medical use in the United States in 1992. [12] [21] It became available as a generic medication in 2007. [22] Zolpidem is a schedule IV controlled substance under the Controlled Substances Act of 1970 (CSA). [7] [8] More than ten million prescriptions are filled each year in the United States, making it one of the most commonly used treatments for sleeping problems. [23] [24] In 2022, it was the 66th most commonly prescribed medication in the United States, with more than 9 million prescriptions. [25] [26]
Zolpidem is labeled for short-term (usually about two to six weeks) treatment of insomnia at the lowest possible dose. [12] [16] It may be used for both improving sleep onset, sleep onset latency, and staying asleep. [7]
Guidelines from NICE, the European Sleep Research Society, and the American College of Physicians recommend medication for insomnia (including possible zolpidem) only as a second-line treatment after non-pharmacological treatment options have been tried (e.g. cognitive behavioral therapy for insomnia). [17] [18] [19] This is based in part on a 2012 review which found that zolpidem's effectiveness is nearly as much due to psychological effects as to the medication itself. [27]
Use of zolpidem may impair driving skills with a resultant increased risk of road traffic accidents. This adverse effect is not unique to zolpidem but also occurs with other hypnotic drugs. Caution should be exercised by motor vehicle drivers. [16] The U.S. Food and Drug Administration (FDA) recommends lower doses of zolpidem due to impaired function the day after taking it. [28] [29] [30] [31] [32]
Zolpidem should not be prescribed to older people, who are more sensitive to the effects of hypnotics including zolpidem, and are at an increased risk of falls and adverse cognitive effects, such as delirium and neurocognitive disorder. [33] [34]
Animal studies have revealed evidence of incomplete ossification and increased intrauterine fetal death at doses greater than seven times the maximum recommended human dose or higher; however, teratogenicity was not observed at any dose level. There are no controlled data on human pregnancy. In one case report, zolpidem was found in cord blood at delivery. Zolpidem is recommended for use during pregnancy only when the benefits outweigh the risks. [35]
The most common adverse effects of short-term use include headache (reported by 7% of people in clinical trials), drowsiness (2%), dizziness (1%), and diarrhea (1%); the most common side effects of long-term use included drowsiness (8%), dizziness (5%), allergy (4%), sinusitis (4%), back pain (3%), diarrhea (3%), drugged feeling (3%), dry mouth (3%), lethargy (3%), sore throat (3%), abdominal pain (2%), constipation (2%), heart palpitations (2%), lightheadedness (2%), rash (2%), abnormal dreams (1%), amnesia (1%), chest pain (1%), depression (1%), flu-like symptoms (1%), and sleep disorder (1%). [8]
Zolpidem increases the risk of depression, falls and bone fracture, poor driving, suppressed respiration and has been associated with an increased risk of death. [36] Upper and lower respiratory infections are also common (experienced by 1–10% of people). [16]
Residual 'hangover' effects, such as sleepiness and impaired psychomotor and cognitive function, may persist into the day following nighttime administration. Such effects may impair the ability of users to drive safely and increase risks of falls and hip fractures. [20] [37] Around 3% of people taking zolpidem are likely to break a bone as a result of a fall due to impaired coordination caused by the drug. [38]
Some users have reported unexplained sleepwalking while using zolpidem, as well as sleep-driving, night eating syndrome while asleep, and performing other daily tasks while sleeping. [20] Research by Australia's National Prescribing Service found these events occur mostly after the first dose taken, or within a few days of starting therapy. [39] In February 2008, the Australian Therapeutic Goods Administration attached a boxed warning concerning this adverse effect. [40]
As zolpidem is associated with drug tolerance and substance dependence, its prescription guidelines are only for severe insomnia and short periods of use at the lowest effective dose. [16] [17] [18] [19] [41] Tolerance to the effects of zolpidem can develop in some people in just a few weeks. [42] Abrupt withdrawal may cause delirium, seizures, or other adverse effects, especially if used for prolonged periods and at high doses. [42] [43] When drug tolerance and physical dependence to zolpidem develop, treatment usually entails a gradual dose reduction over a period of months to minimize withdrawal symptoms, which can resemble those seen during benzodiazepine withdrawal. [43] Failing that, an alternative method may be necessary for some people, such as a switch to a benzodiazepine equivalent dose of a longer-acting benzodiazepine drug, as for diazepam or chlordiazepoxide, followed by a gradual reduction in dose of the long-acting benzodiazepine. [43] In people who are difficult to treat, an inpatient flumazenil administration allows for rapid competitive binding of flumazenil to GABAA–receptor as an antagonist, thus stopping (and effectively detoxifying) zolpidem from being able to bind as an agonist on GABAA–receptor; slowly drug dependence or addiction to zolpidem will wane. [44]
Alcoholics or recovering alcoholics may be at increased risk of physical dependency or abuse of zolpidem. [16] It is not typically prescribed in people with a history of alcoholism, recreational drug use, physical dependency, or psychological dependency on sedative-hypnotic drugs. [16] A 2014 review found evidence of drug-seeking behavior, with prescriptions for zolpidem making up 20% of falsified or forged prescriptions. [45]
Rodent studies of the tolerance-inducing properties have shown that zolpidem has less tolerance-producing potential than benzodiazepines, but in primates, the tolerance-producing potential of zolpidem was the same as seen with benzodiazepines. [46]
Overdose can lead to coma or death. [16]
Zolpidem overdose can be treated with the GABAA receptor antagonist flumazenil, which displaces zolpidem from its binding site on the GABAA receptor to rapidly reverse the effects of the zolpidem. [16]
Zolpidem may be quantitated in blood or plasma to confirm a diagnosis of poisoning in people who are hospitalized, to provide evidence in an impaired driving arrest, or to assist in a medicolegal death investigation. Blood or plasma zolpidem concentrations are usually in a range of 30–300 μg/L in persons receiving the drug therapeutically, 100–700 μg/L in those arrested for impaired driving, and 1000–7000 μg/L in victims of acute overdosage. Analytical techniques, in general, involve gas or liquid chromatography. [47] [48] [49]
Zolpidem is a ligand of high-affinity positive modulator sites of GABAA receptors, which enhances GABAergic inhibition of neurotransmission in the central nervous system. It selectively binds to α1 subunits of this pentameric ion channel. Accordingly, it has strong hypnotic properties and weak anxiolytic, myorelaxant, and anticonvulsant properties. [9] 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. [50] 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. [51] [52] 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. [53] 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. [54] 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. [55]
Like zaleplon, zolpidem may increase slow-wave sleep but cause no effect on stage 2 sleep. [56] 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. [57]
Microsome studies indicate zolpidem is metabolized by CYP3A4 (61%) CYP2C9 (22%), CYP1A2 (14%), CYP2D6 (<3%), and CYP2C19 (<3%). [10] Less than 1% is excreted in urine unchanged. [9] It is principally metabolized into three metabolites, none of which are believed to be pharmacologically active. The absolute bioavailability of zolpidem is about 70%. The drug reaches peak concentration in about 2 hours and has a half-life in healthy adults of about 2–3 hours. [12] [9] [13] Zolpidem's half life is decreased in children and increased in the elderly and people with liver issues. While some studies show men metabolize zolpidem faster than women (possibly due to testosterone), [58] others do not. [9] A review found only a 33% lower clearance in women compared to men, suggesting the FDA's dosage reduction of 50% for women may have been too large. [59]
People should not consume alcohol while taking zolpidem, and should not be prescribed opioid drugs nor take such illicit drugs recreationally. [60] Use of opioids with zolpidem increases the risk of respiratory depression and death. [16] The U.S. Food and Drug Administration (FDA) is advising that the opioid addiction medications buprenorphine and methadone should not be withheld from patients taking benzodiazepines or other drugs that depress the central nervous system (CNS). [61]
Next day sedation can be worsened if people take zolpidem while they are also taking antipsychotics, other sedatives, anxiolytics, antidepressants, anticonvulsants, and antihistamines. Some people taking antidepressants have had visual hallucinations when they also took zolpidem. [16]
Cytochrome P450 inhibitors, particularly CYP3A4 and CYP1A2 inhibitors such as fluvoxamine, ciprofloxacin, and clarithromycin [62] will increase the effects of a given dose of zolpidem. [16] Cytochrome P450 activators like St. John's Wort may decrease the activity of zolpidem. [16] One study found that caffeine increases the concentration over time curve of zolpidem by about 20% and furthermore found that caffeine cannot adequately compensate for the impaired cognition caused by zolpidem. [63] Other studies show no effect of caffeine on zolpidem metabolism. [9]
Three chemical syntheses of zolpidem are common. 4-Methylacetophenone is used as a common precursor. This is brominated and reacted with 2-amino-5-methylpyridine to give the imidazopyridine. From here the reactions use a variety of reagents to complete the synthesis, either involving thionyl chloride or sodium cyanide. These reagents are challenging to handle and require thorough safety assessments. [64] [65] [66] Though such safety procedures are common in the industry, they make clandestine manufacture difficult.
Several major side-products of the sodium cyanide reaction have been characterised and include dimers and mannich products. [67]
Alpidem is also an imidazopyridine and is an analogue of zolpidem. [68] [69] [70] Both agents are GABAA receptor positive allosteric modulators. [68] [69] [70] However, whereas zolpidem is used as a hypnotic and sedative, alpidem was used as an anxiolytic. [68] [69] [70]
Zolpidem was used in Europe starting in 1988 and was brought to market there by Synthelabo. [71] Synthelabo and Searle collaborated to bring it to market in the US, and it was approved in the United States in 1992 under the brand name "Ambien". [71] [21] It became available as a generic medication in 2007. [22]
In 2015, the American Geriatrics Society said that zolpidem, eszopiclone, and zaleplon met the Beers criteria and should be avoided in individuals 65 and over "because of their association with harms balanced with their minimal efficacy in treating insomnia." [33] [34] The AGS stated the strength of the recommendation that older adults avoid zolpidem is "strong" and the quality of evidence supporting it is "moderate." [34]
Prescriptions in the US for all sleeping pills (including zolpidem) steadily declined from around 57 million tablets in 2013, to around 47 million in 2017, possibly due to concern about prescribing addictive drugs amid the opioid crisis. [72]
The United States Air Force uses zolpidem as one of the hypnotics approved as a "no-go pill" (with a six-hour restriction on subsequent flight operation) to help aviators and special duty personnel sleep in support of mission readiness. (The other hypnotics used are temazepam and zaleplon.) "Ground tests" are required before an authorization issued to use the medication in an operational situation. [73]
Zolpidem has potential for medical misuse when the drug is continued long term without or against medical advice, or for recreational use when the drug is taken to achieve a "high". [74] [75] The transition from medical use of zolpidem to high-dose addiction or drug dependence can occur with use, but some believe it may be more likely when used without a clinical recommendation to continue using it, when physiological drug tolerance leads to higher doses than the usual 5 mg or 10 mg, when consumed through insufflation or injection, or when taken for purposes other than as a sleep aid. [74] Recreational use is more prevalent in those having been dependent on other drugs in the past, but tolerance and drug dependence can still sometimes occur in those without a history of drug dependence. Chronic users of high doses are more likely to develop physical dependence on the drug, which may cause severe withdrawal symptoms, including seizures if abrupt withdrawal from zolpidem occurs. [76]
Other drugs, including benzodiazepines and zopiclone, are also found in high numbers of suspected drugged drivers. [20] Many drivers have blood levels far exceeding the therapeutic dose range, suggesting a high degree of excessive-use potential for benzodiazepines, zolpidem, and zopiclone. [47] U.S. Congressman Patrick J. Kennedy says that he was using zolpidem (Ambien) and promethazine (Phenergan) when he was caught driving erratically at 3 a.m. [77] "I simply do not remember getting out of bed, being pulled over by the police, or being cited for three driving infractions," Kennedy said.
As of 2009 [update] , nonmedical use of zolpidem is common for some adolescents. Some users have reported decreased anxiety, mild euphoria, perceptual changes, visual distortions, and hallucinations. [78] [79] Zolpidem was used by Australian Olympic swimmers at the London Olympics in 2012, leading to controversy. [80]
For the stated reason of its potential for recreational use and dependence, zolpidem (along with the other benzodiazepine-like Z-drugs) is a schedule IV substance under the Controlled Substances Act in the US. The United States patent for zolpidem was held by the French pharmaceutical corporation Sanofi-Aventis. [81]
The Z-drugs, including zolpidem, have been used as date rape drugs. [20] [82] Zolpidem is available legally by prescription, and broadly prescribed unlike other date rape drugs: gamma-hydroxybutyrate (GHB), which is used to treat narcolepsy, or flunitrazepam (Rohypnol), which is only prescribed as a second-line choice for insomnia. [83] 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. [20] 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. [83] [84]
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. [85]
As of September 2018, zolpidem is marketed under many brands. [1]
While cases of zolpidem improving aphasia in people with stroke have been described, use for this purpose has unclear benefits. [86] Zolpidem has also been studied in persistent vegetative states with unclear effect. [87] A 2017 systematic review concluded that while there is preliminary evidence of benefit for treating disorders of movement and consciousness other than insomnia (including Parkinson's disease), more research is needed. [88]
Animal studies in FDA files for zolpidem showed a dose dependent increase in some types of tumors, although the studies were too small to reach statistical significance. [89] Some observational epidemiological studies have found a correlation between use of benzodiazepines and certain hypnotics including zolpidem and an increased risk of getting cancer, but others have found no correlation; a 2017 meta-analysis of such studies found a correlation, stating that use of hypnotics was associated with a 29% increased risk of cancer, and that "zolpidem use showed the strongest risk of cancer" with an estimated 34% increased risk, but noted that the results were tentative because some of the studies failed to control for confounders like cigarette smoking and alcohol use, and some of the studies analyzed were case–controls, which are more prone to some forms of bias. [90] Similarly, a meta-analysis of benzodiazepine drugs also shows their use is associated with increased risk of cancer. [91]
Benzodiazepines, colloquially known as "benzos", are a class of depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed to treat conditions such as anxiety disorders, insomnia, and seizures. The first benzodiazepine, chlordiazepoxide (Librium), was discovered accidentally by Leo Sternbach in 1955, and was made available in 1960 by Hoffmann–La Roche, which followed with the development of diazepam (Valium) three years later, in 1963. By 1977, benzodiazepines were the most prescribed medications globally; the introduction of selective serotonin reuptake inhibitors (SSRIs), among other factors, decreased rates of prescription, but they remain frequently used worldwide.
Hypnotic, or soporific drugs, commonly known as sleeping pills, are a class of psychoactive drugs whose primary function is to induce sleep and to treat insomnia (sleeplessness).
Temazepam, sold under the brand name Restoril among others, is a medication of the benzodiazepine class which is generally used to treat severe or debilitating insomnia. It is taken by mouth. Temazepam is rapidly absorbed, and significant hypnotic effects begin in less than 30 minutes and can last for up to eight hours. Prescriptions for hypnotics such as temazepam have seen a dramatic decrease since 2010, while anxiolytics such as alprazolam, clonazepam, and lorazepam have increased or remained stable. Temazepam and similar hypnotics, such as triazolam (Halcion) are generally reserved for severe and debilitating insomnia. They have largely been replaced by z-drugs and atypical antidepressants as first line treatment for insomnia.
Triazolam, sold under the brand name Halcion among others, is a central nervous system (CNS) depressant tranquilizer of the triazolobenzodiazepine (TBZD) class, which are benzodiazepine (BZD) derivatives. It possesses pharmacological properties similar to those of other benzodiazepines, but it is generally only used as a sedative to treat severe insomnia. In addition to the hypnotic properties, triazolam's amnesic, anxiolytic, sedative, anticonvulsant, and muscle relaxant properties are pronounced as well.
Flumazenil is a selective GABAA receptor antagonist administered via injection, otic insertion, or intranasally. Therapeutically, it acts as both an antagonist and antidote to benzodiazepines, through competitive inhibition.
Zopiclone, sold under the brand name Imovane among others, is a nonbenzodiazepine, specifically a cyclopyrrolone, used to treat difficulty sleeping. Zopiclone is molecularly distinct from benzodiazepine drugs and is classed as a cyclopyrrolone. However, zopiclone increases the normal transmission of the neurotransmitter gamma-aminobutyric acid (GABA) in the central nervous system, via modulating GABAA receptors similarly to the way benzodiazepine drugs do inducing sedation but not with the anti-anxiety properties of the benzodiazepines.
Nitrazepam, sold under the brand name Mogadon among others, is a hypnotic drug of the benzodiazepine class used for short-term relief from severe, disabling anxiety and insomnia. It also has sedative (calming) properties, as well as amnestic, anticonvulsant, and skeletal muscle relaxant effects.
Flurazepam is a drug which is a benzodiazepine derivative. It possesses anxiolytic, anticonvulsant, hypnotic, sedative and skeletal muscle relaxant properties. It produces a metabolite with a long half-life, which may stay in the bloodstream for days. Flurazepam was patented in 1968 and came into medical use the same year. Flurazepam, developed by Roche Pharmaceuticals, was one of the first benzodiazepine hypnotic medications to be marketed.
Eszopiclone, sold under the brand name Lunesta among others, is a medication used in the treatment of insomnia. Evidence supports slight to moderate benefit up to six months. It is taken by mouth.
Zaleplon, sold under the brand name Sonata among others, is a sedative and hypnotic which is used to treat insomnia. It is a nonbenzodiazepine or Z-drug of the pyrazolopyrimidine class. It was developed by King Pharmaceuticals and approved for medical use in the United States in 1999.
Nonbenzodiazepines, sometimes referred to colloquially as Z-drugs, are a class of psychoactive, depressant, sedative, hypnotic, anxiolytic drugs that are benzodiazepine-like in uses, such as for treating insomnia and anxiety.
Quazepam, sold under the brand name Doral among others, is a relatively long-acting benzodiazepine derivative drug developed by the Schering Corporation in the 1970s. Quazepam is used for the treatment of insomnia, including sleep induction and sleep maintenance. Quazepam induces impairment of motor function and has relatively selective hypnotic and anticonvulsant properties with considerably less overdose potential than other benzodiazepines. Quazepam is an effective hypnotic which induces and maintains sleep without disruption of the sleep architecture.
Estazolam, sold under the brand name Prosom among others, is a tranquilizer medication of the triazolobenzodiazepine (TBZD) class, which are benzodiazepines (BZDs) fused with a triazole ring. It possesses anxiolytic, anticonvulsant, hypnotic, sedative and skeletal muscle relaxant properties. Estazolam is an intermediate-acting oral benzodiazepine. It is used for short-term treatment of insomnia.
Clorazepate, sold under the brand name Tranxene among others, is a benzodiazepine medication. It possesses anxiolytic, anticonvulsant, sedative, hypnotic, and skeletal muscle relaxant properties. Clorazepate is an unusually long-lasting benzodiazepine and serves as a prodrug for the equally long-lasting desmethyldiazepam, which is rapidly produced as an active metabolite. Desmethyldiazepam is responsible for most of the therapeutic effects of clorazepate.
Alpidem, sold under the brand name Ananxyl, is a nonbenzodiazepine anxiolytic medication which was briefly used to treat anxiety disorders but is no longer marketed. It was previously marketed in France, but was discontinued due to liver toxicity. Alpidem is taken by mouth.
Loprazolam (triazulenone) marketed under many brand names is a benzodiazepine medication. It possesses anxiolytic, anticonvulsant, hypnotic, sedative and skeletal muscle relaxant properties. It is licensed and marketed for the short-term treatment of moderately-severe insomnia.
Lormetazepam, sold under the brand name Noctamid among others, is a drug which is a short to intermediate acting 3-hydroxy benzodiazepine derivative and temazepam analogue. It possesses hypnotic, anxiolytic, anticonvulsant, sedative, and skeletal muscle relaxant properties.
Bretazenil (Ro16-6028) is an imidazopyrrolobenzodiazepine anxiolytic drug which is derived from the benzodiazepine family, and was invented in 1988. It is most closely related in structure to the GABA antagonist flumazenil, although its effects are somewhat different. It is classified as a high-potency benzodiazepine due to its high affinity binding to benzodiazepine binding sites where it acts as a partial agonist. Its profile as a partial agonist and preclinical trial data suggests that it may have a reduced adverse effect profile. In particular bretazenil has been proposed to cause a less strong development of tolerance and withdrawal syndrome. Bretazenil differs from traditional 1,4-benzodiazepines by being a partial agonist and because it binds to α1, α2, α3, α4, α5 and α6 subunit containing GABAA receptor benzodiazepine receptor complexes. 1,4-benzodiazepines bind only to α1, α2, α3 and α5GABAA benzodiazepine receptor complexes.
Benzodiazepine dependence defines a situation in which one has developed one or more of either tolerance, withdrawal symptoms, drug seeking behaviors, such as continued use despite harmful effects, and maladaptive pattern of substance use, according to the DSM-IV. In the case of benzodiazepine dependence, the continued use seems to be typically associated with the avoidance of unpleasant withdrawal reaction rather than with the pleasurable effects of the drug. Benzodiazepine dependence develops with long-term use, even at low therapeutic doses, often without the described drug seeking behavior and tolerance.
Somnifacient, also known as sedatives or sleeping pills, is a class of medications that induces sleep. It is mainly used for treatment of insomnia. Examples of somnifacients include benzodiazepines, barbiturates and antihistamines.