List of benzodiazepines


The tables below contain a sample list of benzodiazepines and benzodiazepine analogs that are commonly prescribed, with their basic pharmacological characteristics, such as half-life and equivalent doses to other benzodiazepines, also listed, along with their trade names and primary uses. The elimination half-life is how long it takes for half of the drug to be eliminated by the body. "Time to peak" refers to when maximum levels of the drug in the blood occur after a given dose. Benzodiazepines generally share the same pharmacological properties, such as anxiolytic, sedative, hypnotic, skeletal muscle relaxant, amnesic, and anticonvulsant effects. Variation in potency of certain effects may exist amongst individual benzodiazepines. Some benzodiazepines produce active metabolites. Active metabolites are produced when a person's body metabolizes the drug into compounds that share a similar pharmacological profile to the parent compound and thus are relevant when calculating how long the pharmacological effects of a drug will last. Long-acting benzodiazepines with long-acting active metabolites, such as diazepam and chlordiazepoxide, are often prescribed for benzodiazepine or alcohol withdrawal as well as for anxiety if constant dose levels are required throughout the day. Shorter-acting benzodiazepines are often preferred for insomnia due to their lesser hangover effect.
It is fairly important to note that elimination half-life of diazepam and chlordiazepoxide, as well as other long half-life benzodiazepines, is twice as long in the elderly compared to younger individuals. Due to increased sensitivity and potentially dangerous adverse events among elderly patients, it is recommended to avoid prescribing them as specified by the 2015 American Geriatrics Society Beers Criteria. Individuals with an impaired liver also metabolize benzodiazepines more slowly. Thus, the approximate equivalent of doses below may need to be adjusted accordingly in individuals on short acting benzodiazepines who metabolize long-acting benzodiazepines more slowly and vice versa. The changes are most notable with long acting benzodiazepines as these are prone to significant accumulation in such individuals and can lead to withdrawal symptoms. For example, the equivalent dose of diazepam in an elderly individual on lorazepam may be half of what would be expected in a younger individual. Equivalent doses of benzodiazepines differ as much as 20 fold.

Pharmacokinetic properties of various benzodiazepines

Equivalency data in the table below is taken from the Ashton "Benzodiazepine Equivalence Table".
Drug NameCommon Trade NamesYear Approved
Typical Oral Dosage Formulations
'
Approx. Equivalent Oral Dose to 10 mg Diazepam Peak Onset of Action
Elimination Half-life of Active Metabolite Primary Therapeutic Use
AdinazolamDeracyn1–23anxiolytic, antidepressant
AlprazolamAlprox, Farmapram, Frontin, Helex, Kalma, Ksalol, Misar, Neurol, Onax, Restyl, Solanax, Tafil, Trankimazin, Xanax, Xanor0.25, 0.5, 1, 20.51–311-13 anxiolytic, antidepressant
BentazepamThiadipona251–32–4anxiolytic
Bretazenil2.5anxiolytic, anticonvulsant
BromazepamBromam, Lectopam, Lexatin, Lexaurin, Lexilium, Lexotan, Lexotanil1.5, 3, 661–520–40anxiolytic,
hypnotic, muscle relaxant
Bromazolam2, 42anxiolytic
BrotizolamDormex, Lendormin, Noctilan, Sintonal,0.250.50.5–24–5hypnotic
CamazepamAlbego, Limpidon401–36–11anxiolytic
ChlordiazepoxideElenium, Librium, Risolid5, 10, 25251.5–636–200anxiolytic
CinazepamLevana0.5, 1, 22–460hypnotic, anxiolytic
CinolazepamGerodorm400.5–29hypnotic
ClobazamFrisium, Onfi, Urbanol5, 10, 20201–58–60anxiolytic, anticonvulsant
ClonazepamIktorivil, Klonopin, Paxam, Rivatril, Rivotril0.5, 1, 20.5-11–519.5–50anticonvulsant, anxiolytic
Clonazolam0.25, 0.50.20.5-13-4hypnotic, anticonvulsant
ClorazepateTranxene, Tranxilium3.75, 5, 7.515Variable32–152anxiolytic, anticonvulsant
ClotiazepamClozan, Rize, Veratran5, 10101–34anxiolytic
CloxazolamCloxam, Olcadil, Sepazon1, 2, 41.52–555–77anxiolytic, anticonvulsant
DelorazepamDadumir0.5, 1, 21-1.51–279<anxiolytic, amnesic
Deschloroetizolam1, 24anxiolytic
DiazepamAntenex, Apaurin, Apozepam, Apzepam, Diazepan, Hexalid, Normabel, Pax, Stedon, Stesolid, Tranquirit, Valaxona, Valium, Vival2, 5, 10101–1.532–205anxiolytic, anticonvulsant, muscle relaxant, amnesic
Diclazepam1, 221.5–342anxiolytic, muscle relaxant
EstazolamProSom, Nuctalon1, 223–510–24hypnotic, anxiolytic
Ethylbromazolam4 anxiolytic
Ethyl carfluzepate21–511–24hypnotic
EtizolamDepas, Etilaam, Etizest, Pasaden121–35-7anxiolytic, muscle relaxant, anticonvulsant
Ethyl loflazepateMeilax, Ronlax, Victan22.5–373–119anxiolytic
Flualprazolam0.5, 10.251-212-22anxiolytic, hypnotic
FlubromazepamTemplex4, 8, 1241.5–8100–220anxiolytic, hypnotic, amnesic, muscle relaxant, anticonvulsant
FlubromazolamRemnon0.25, 0.50.0750.5-510-20hypnotic
Fluclotizolam0.25-0.5anxiolytic
FlunitrazepamFlunipam, Fluscand, Hipnosedon, Hypnodorm, Rohydorm, Rohypnol, Ronal, Vulbegal1, 21.50.5–318–200hypnotic
Flunitrazolam0.25, 0.50.10.5-15-13hypnotic
FlurazepamDalmadorm, Dalmane, Fluzepam3020-251–1.540–250hypnotic
FlutazolamCoreminal4101-347-100hypnotic
Flutemazepam10.5-58-20hypnotic, anxiolytic, anticonvulsant, muscle relaxant
FlutoprazepamRestas1, 22.50.5–987hypnotic, anticonvulsant, muscle relaxant
HalazepamAlapryl, Paxipam20, 40403–615-35 anxiolytic
KetazolamAnxon, Sedotime15, 30, 45202.5–630-100 anxiolytic
LoprazolamDormonoct, Havlane1, 21.52–56–20hypnotic
LorazepamAtivan, Lorabenz, Lorenin, Lorsilan, Orfidal, Tavor, Temesta0.5, 1, 2, 2.512–410–20anxiolytic, anticonvulsant, hypnotic, muscle relaxant
LormetazepamLoramet, Noctamid, Pronoctan1, 21.50.5–210-12hypnotic, anxiolytic
Meclonazepam6anxiolytic
MedazepamAnsilan, Mezapam, Nobrium, Raporan, Rudotel10104-836–200anxiolytic
Metizolam1, 2, 42–412anxiolytic
MexazolamMelex, Sedoxil0.5, 11–2anxiolytic
MidazolamDormicum, Dormonid, Flormidal, Hypnovel, Versed7.5, 1510
4
0.5–11.8-6hypnotic, anticonvulsant
Nifoxipam0.5, 1, 2hypnotic
NimetazepamErimin, Lavol52.5-50.5–314–30hypnotic
Nitemazepam20.5-510-27hypnotic, anticonvulsant
NitrazepamAlodorm, Dumolid, Mogadon, Nitrazadon, Pacisyn5, 1050.5–717–48hypnotic, anticonvulsant
Nitrazolam0.5, 1hypnotic
NordazepamMadar, Stilny5, 7.5, 1510-1530–150anxiolytic
Norflurazepam547-100hypnotic
OxazepamAlepam, Medopam, Murelax, Noripam, Ox-Pam, Opamox, Oxabenz, Oxapax, Oxascand, Purata, Serax, Serenid, Serepax, Seresta, Sobril10, 15, 30, 50303–44–11anxiolytic
PhenazepamPhenazepam, Phenzitat1.5–460anxiolytic, anticonvulsant
PinazepamDomar, Duna5, 1040–100anxiolytic
PrazepamCentrax, Demetrin, Lysanxia, Prazene10, 20, 3015-202–636–200anxiolytic
Premazepam152–610–13anxiolytic
Pyrazolam0.25, 0.5, 11–1.516–18anxiolytic, amnesic
QuazepamDoral, Quiedorm15201–539–120hypnotic
RilmazafoneRhythmy11hypnotic
TemazepamEuhypnos, Normison, Restoril, Temaze, Tenox10, 2015-200.5–34–11hypnotic, anxiolytic, muscle relaxant
TetrazepamClinoxam, Epsipam, Musaril, Myolastan501–33–26muscle relaxant, anxiolytic
TriazolamHalcion, Notison, Rilamir, Somese0.125, 0.250.50.5–22hypnotic
Drug NameCommon Trade NamesYear ApprovedTypical Dosages of Oral Tablets
'
Approx. Equivalent Oral Dose to 10 mg Diazepam Peak onset of action Elimination Half-life of Active Metabolite Primary Therapeutic Use

Controversy

In 2015 the UK's House of Commons attempted to get a two to four week limit mandate for prescribing benzodiazepines to replace the two to four week benzodiazepine prescribing guidelines, which are merely recommended.

Binding data and structure-activity relationship

A large number of benzodiazepine derivatives have been synthesised and their structure-activity relationships explored in detail. This chart contains binding data for benzodiazepines and related drugs investigated by Roche up to the late 1990s. Other benzodiazepines are also listed for comparison purposes, but it does not however include binding data for;
  • Benzodiazepines developed in the former Soviet Union
  • Benzodiazepines predominantly used only in Japan
  • 4,5-cyclised benzodiazepines, and other compounds not researched by Roche
  • Benzodiazepines developed more recently
  • "Designer" benzodiazepines for which in vitro binding data are unavailable
While binding or activity data are available for most of these compounds also, the assay conditions vary between sources, meaning that in many cases the values are not suitable for a direct comparison. Many older sources used animal measures of activity but did not measure in vitro binding to benzodiazepine receptors. See for instance Table 2 vs Table 11 in the Chem Rev paper, Table 2 lists in vitro pIC50 values matching those below, while Table 11 has pEC50 values derived from in vivo assays in mice, which show the same activity trends but cannot be compared directly, and includes data for compounds such as diclazepam and flubromazepam which are not available in the main data set.
Also note;
  • IC50 / pIC50 values represent binding affinity only and do not reflect efficacy or pharmacokinetics, and some compounds listed are GABAA antagonists rather than agonists.
  • Low IC50 or high pIC50 values indicate tighter binding
  • These are non subtype selective IC50 values averaged across all GABAA receptor subtypes, so subtype selective compounds with strong binding at one subtype but weak at others will appear unusually weak due to averaging of binding values indicates a predicted value from in silico modelling.
  • Finally, note that the benzodiazepine core is a privileged scaffold, which has been used to derive drugs with diverse activity that is not limited to the GABAA modulatory action of the classical benzodiazepines, such as devazepide and tifluadom, however these have not been included in the list below. 2,3-benzodiazepines such as tofisopam are also not listed, as these act primarily as AMPA receptor modulators, and are inactive at GABAA receptors.