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 Name | Common Trade Names | Year 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 |
| Adinazolam | Deracyn | 1–2 | 3 | anxiolytic, antidepressant | |||
| Alprazolam | Alprox, Farmapram, Frontin, Helex, Kalma, Ksalol, Misar, Neurol, Onax, Restyl, Solanax, Tafil, Trankimazin, Xanax, Xanor | 0.25, 0.5, 1, 2 | 0.5 | 1–3 | 11-13 | anxiolytic, antidepressant | |
| Bentazepam | Thiadipona | 25 | 1–3 | 2–4 | anxiolytic | ||
| Bretazenil | 2.5 | anxiolytic, anticonvulsant | |||||
| Bromazepam | Bromam, Lectopam, Lexatin, Lexaurin, Lexilium, Lexotan, Lexotanil | 1.5, 3, 6 | 6 | 1–5 | 20–40 | anxiolytic, hypnotic, muscle relaxant | |
| Bromazolam | 2, 4 | 2 | anxiolytic | ||||
| Brotizolam | Dormex, Lendormin, Noctilan, Sintonal, | 0.25 | 0.5 | 0.5–2 | 4–5 | hypnotic | |
| Camazepam | Albego, Limpidon | 40 | 1–3 | 6–11 | anxiolytic | ||
| Chlordiazepoxide | Elenium, Librium, Risolid | 5, 10, 25 | 25 | 1.5–6 | 36–200 | anxiolytic | |
| Cinazepam | Levana | 0.5, 1, 2 | 2–4 | 60 | hypnotic, anxiolytic | ||
| Cinolazepam | Gerodorm | 40 | 0.5–2 | 9 | hypnotic | ||
| Clobazam | Frisium, Onfi, Urbanol | 5, 10, 20 | 20 | 1–5 | 8–60 | anxiolytic, anticonvulsant | |
| Clonazepam | Iktorivil, Klonopin, Paxam, Rivatril, Rivotril | 0.5, 1, 2 | 0.5-1 | 1–5 | 19.5–50 | anticonvulsant, anxiolytic | |
| Clonazolam | 0.25, 0.5 | 0.2 | 0.5-1 | 3-4 | hypnotic, anticonvulsant | ||
| Clorazepate | Tranxene, Tranxilium | 3.75, 5, 7.5 | 15 | Variable | 32–152 | anxiolytic, anticonvulsant | |
| Clotiazepam | Clozan, Rize, Veratran | 5, 10 | 10 | 1–3 | 4 | anxiolytic | |
| Cloxazolam | Cloxam, Olcadil, Sepazon | 1, 2, 4 | 1.5 | 2–5 | 55–77 | anxiolytic, anticonvulsant | |
| Delorazepam | Dadumir | 0.5, 1, 2 | 1-1.5 | 1–2 | 79< | anxiolytic, amnesic | |
| Deschloroetizolam | 1, 2 | 4 | anxiolytic | ||||
| Diazepam | Antenex, Apaurin, Apozepam, Apzepam, Diazepan, Hexalid, Normabel, Pax, Stedon, Stesolid, Tranquirit, Valaxona, Valium, Vival | 2, 5, 10 | 10 | 1–1.5 | 32–205 | anxiolytic, anticonvulsant, muscle relaxant, amnesic | |
| Diclazepam | 1, 2 | 2 | 1.5–3 | 42 | anxiolytic, muscle relaxant | ||
| Estazolam | ProSom, Nuctalon | 1, 2 | 2 | 3–5 | 10–24 | hypnotic, anxiolytic | |
| Ethylbromazolam | 4 | anxiolytic | |||||
| Ethyl carfluzepate | 2 | 1–5 | 11–24 | hypnotic | |||
| Etizolam | Depas, Etilaam, Etizest, Pasaden | 1 | 2 | 1–3 | 5-7 | anxiolytic, muscle relaxant, anticonvulsant | |
| Ethyl loflazepate | Meilax, Ronlax, Victan | 2 | 2.5–3 | 73–119 | anxiolytic | ||
| Flualprazolam | 0.5, 1 | 0.25 | 1-2 | 12-22 | anxiolytic, hypnotic | ||
| Flubromazepam | Templex | 4, 8, 12 | 4 | 1.5–8 | 100–220 | anxiolytic, hypnotic, amnesic, muscle relaxant, anticonvulsant | |
| Flubromazolam | Remnon | 0.25, 0.5 | 0.075 | 0.5-5 | 10-20 | hypnotic | |
| Fluclotizolam | 0.25-0.5 | anxiolytic | |||||
| Flunitrazepam | Flunipam, Fluscand, Hipnosedon, Hypnodorm, Rohydorm, Rohypnol, Ronal, Vulbegal | 1, 2 | 1.5 | 0.5–3 | 18–200 | hypnotic | |
| Flunitrazolam | 0.25, 0.5 | 0.1 | 0.5-1 | 5-13 | hypnotic | ||
| Flurazepam | Dalmadorm, Dalmane, Fluzepam | 30 | 20-25 | 1–1.5 | 40–250 | hypnotic | |
| Flutazolam | Coreminal | 4 | 10 | 1-3 | 47-100 | hypnotic | |
| Flutemazepam | 1 | 0.5-5 | 8-20 | hypnotic, anxiolytic, anticonvulsant, muscle relaxant | |||
| Flutoprazepam | Restas | 1, 2 | 2.5 | 0.5–9 | 87 | hypnotic, anticonvulsant, muscle relaxant | |
| Halazepam | Alapryl, Paxipam | 20, 40 | 40 | 3–6 | 15-35 | anxiolytic | |
| Ketazolam | Anxon, Sedotime | 15, 30, 45 | 20 | 2.5–6 | 30-100 | anxiolytic | |
| Loprazolam | Dormonoct, Havlane | 1, 2 | 1.5 | 2–5 | 6–20 | hypnotic | |
| Lorazepam | Ativan, Lorabenz, Lorenin, Lorsilan, Orfidal, Tavor, Temesta | 0.5, 1, 2, 2.5 | 1 | 2–4 | 10–20 | anxiolytic, anticonvulsant, hypnotic, muscle relaxant | |
| Lormetazepam | Loramet, Noctamid, Pronoctan | 1, 2 | 1.5 | 0.5–2 | 10-12 | hypnotic, anxiolytic | |
| Meclonazepam | 6 | anxiolytic | |||||
| Medazepam | Ansilan, Mezapam, Nobrium, Raporan, Rudotel | 10 | 10 | 4-8 | 36–200 | anxiolytic | |
| Metizolam | 1, 2, 4 | 2–4 | 12 | anxiolytic | |||
| Mexazolam | Melex, Sedoxil | 0.5, 1 | 1–2 | anxiolytic | |||
| Midazolam | Dormicum, Dormonid, Flormidal, Hypnovel, Versed | 7.5, 15 | 10 4 | 0.5–1 | 1.8-6 | hypnotic, anticonvulsant | |
| Nifoxipam | 0.5, 1, 2 | hypnotic | |||||
| Nimetazepam | Erimin, Lavol | 5 | 2.5-5 | 0.5–3 | 14–30 | hypnotic | |
| Nitemazepam | 2 | 0.5-5 | 10-27 | hypnotic, anticonvulsant | |||
| Nitrazepam | Alodorm, Dumolid, Mogadon, Nitrazadon, Pacisyn | 5, 10 | 5 | 0.5–7 | 17–48 | hypnotic, anticonvulsant | |
| Nitrazolam | 0.5, 1 | hypnotic | |||||
| Nordazepam | Madar, Stilny | 5, 7.5, 15 | 10-15 | 30–150 | anxiolytic | ||
| Norflurazepam | 5 | 47-100 | hypnotic | ||||
| Oxazepam | Alepam, Medopam, Murelax, Noripam, Ox-Pam, Opamox, Oxabenz, Oxapax, Oxascand, Purata, Serax, Serenid, Serepax, Seresta, Sobril | 10, 15, 30, 50 | 30 | 3–4 | 4–11 | anxiolytic | |
| Phenazepam | Phenazepam, Phenzitat | 1.5–4 | 60 | anxiolytic, anticonvulsant | |||
| Pinazepam | Domar, Duna | 5, 10 | 40–100 | anxiolytic | |||
| Prazepam | Centrax, Demetrin, Lysanxia, Prazene | 10, 20, 30 | 15-20 | 2–6 | 36–200 | anxiolytic | |
| Premazepam | 15 | 2–6 | 10–13 | anxiolytic | |||
| Pyrazolam | 0.25, 0.5, 1 | 1–1.5 | 16–18 | anxiolytic, amnesic | |||
| Quazepam | Doral, Quiedorm | 15 | 20 | 1–5 | 39–120 | hypnotic | |
| Rilmazafone | Rhythmy | 11 | hypnotic | ||||
| Temazepam | Euhypnos, Normison, Restoril, Temaze, Tenox | 10, 20 | 15-20 | 0.5–3 | 4–11 | hypnotic, anxiolytic, muscle relaxant | |
| Tetrazepam | Clinoxam, Epsipam, Musaril, Myolastan | 50 | 1–3 | 3–26 | muscle relaxant, anxiolytic | ||
| Triazolam | Halcion, Notison, Rilamir, Somese | 0.125, 0.25 | 0.5 | 0.5–2 | 2 | hypnotic | |
| Drug Name | Common Trade Names | Year Approved | Typical 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
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.