List of benzodiazepines

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Lua error in package.lua at line 80: module 'strict' not found. The below tables 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 (hypertension in combination with other antihypertensive medications). 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.[1][2][3][4][5]

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. Individuals with an impaired liver also metabolize benzodiazepines more slowly. Many doctors[who?] make the mistake of not adjusting benzodiazepine dosage according to age in elderly patients. 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.[this quote needs a citation] 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.[6][7] Equivalencies between individual benzodiazepines can differ by 400 fold on a mg per mg basis; awareness of this fact is necessary for the safe and effective use of benzodiazepines.[8]

File:Benzodiazépines en France.jpg
A variety of Benzodiazepines along with their molecular structure.

Pharmacological properties of common benzodiazepines

Data in the table below is taken from the Ashton "Benzodiazepine Equivalency Table".[9][medical citation needed]

Drug Name Common Brand Names* Initial Approval Year Time to Peak (Onset of action in hours) Elimination Half-Life (h)† [active metabolite] (Average hours and days) Therapeutic use
Adinazolam Deracyn 1-2 3h (=0.12d) anxiolytic, antidepressant
Alprazolam Helex, Xanax, Xanor, Onax, Alprox, Restyl, Solanax, Tafil 1981 1-2 10–20 hours (15h=0.62d) anxiolytic, antidepressant
Bentazepam Thiadipona 1-3 2–4 hours (3h=0.12d) anxiolytic
Bretazenil[10] N/A ? 2.5 hours (=0.10d) anxiolytic, anticonvulsant
Bromazepam Lectopam, Lexaurin, Lexotanil, Lexotan, Bromam 1-3 20–40 hours (30h=1.25d) anxiolytic,

hypnotic
Brotizolam Lendormin, Dormex, Sintonal, Noctilan 0.5-2 4–5 hours (4.5h=0.19d) hypnotic
Camazepam Albego, Limpidon, Paxor 0.5-2 6–29 hours (17.5h=0.73d) anxiolytic
Chlordiazepoxide Librium, Risolid, Elenium 1960 1.5-4 5–30 hours [36–200 hours] (17,5h=0,73d [118h=4.92d]) anxiolytic
Cinazepam 2-4 60h (=2.5d) hypnotic, anxiolytic
Cinolazepam Gerodorm 0.5-2 9 hours (=0.37d) hypnotic
Clobazam Onfi, Frisium, Urbanol 2011 1–3 hours 8–60 hours (34h=1.41d) anxiolytic, anticonvulsant
Clonazepam Rivatril, Rivotril, Klonopin, Iktorivil, Paxam 1975 1-4 19.5–50 hours (34.75h=1.45d) anticonvulsant, anxiolytic, muscle relaxant
Clonazolam N/A Research chemical 0.5-1.5 10–18 hours anxiolytic, anticonvulsant, hypnotic, muscle relaxant
Clorazepate Tranxene, Tranxilium 1972 Variable 32–152 hours (92h=3.83d) anxiolytic, anticonvulsant
Clotiazepam Veratran, Clozan, Rize 1-3 4 hours (=0.17d) anxiolytic
Cloxazolam Sepazon, Olcadil 2-5 (?) 80–105 hours (92.5h= 3.85d) anxiolytic, anticonvulsant
Delorazepam Dadumir 1-2 80–105 hours (92,5hh=3.85d) anxiolytic, amnesic
Diazepam Antenex, Apaurin, Apzepam, Apozepam, Hexalid, Pax, Stesolid, Stedon, Valium, Vival, Valaxona 1963 1-1.5 32–47 hours [32–205] (39.5h=1.64d [118.5h=4.94d] anxiolytic, anticonvulsant, muscle relaxant
Diclazepam[11] Research chemical 1.5-3 220 hours (=7days+) anxiolytic, amnesic, anticonvulsant, hypnotic, muscle relaxant
Estazolam ProSom, Nuctalon 1990 1-5 10–31 hours (20.5h=0.85d) hypnotic, anxiolytic
Ethyl carfluzepate N/A 1-5 11–24 hours (17.5h=0.73d) hypnotic
Etizolam Etilaam, Etizest, Pasaden, Depas 1-2 6 hours (=0.25d) anxiolytic, hypnotic, amnesic, muscle relaxant, anticonvulsant
Ethyl loflazepate Victan, Meilax, Ronlax 2.5-3 73–119 hours (96h=4d) anxiolytic
Flubromazepam[12] Research chemical 1.5-4 (4-8) 100–220 hours (160h=6.67d) anxiolytic, hypnotic, amnesic, muscle relaxant, anticonvulsant
Flubromazolam Research chemical ? ? hypnotic
Flunitrazepam Rohypnol, Hipnosedon, Vulbegal, Fluscand, Flunipam, Ronal, Rohydorm, 1983 0.5-3 18–26 hours [36–200 hours] (22h=0.92d [118h=4.92d]) hypnotic
Flurazepam Dalmadorm, Dalmane 1970 1-1.5 40–250 hours (145h=6.04d) hypnotic
Flutazolam Coreminal ? 3.5 hours hypnotic
Flutoprazepam Restas 0.5-9 60–90 hours (75h=3.12d) hypnotic, anticonvulsant
Halazepam Paxipam 1981 1-3 30–100 hours (65h=2.71d) anxiolytic
Ketazolam Anxon N/A 2.5-3 30–100 hours [36–200] (65h=2.71d [118h=4.92d]) anxiolytic
Loprazolam Dormonoct 0.5-4 3.3–14.8 hours (9.05h=0.38d) hypnotic
Lorazepam Ativan, Lorenin, Lorsilan, Temesta, Tavor, Lorabenz 1977 2-4 9.5–20 hours (14.75h=0.61d) anxiolytic, amnesic, anticonvulsant, hypnotic, muscle relaxant[13][14][15]
Lormetazepam Loramet, Noctamid, Pronoctan 0.5-2 10 hours (=0.42d) hypnotic
Medazepam Nobrium, Ansilan, Mezapam, Rudotel, Raporan 1-1.5 36–200 hours (118h=4.92d) anxiolytic
Mexazolam Melex 1-2 [16] anxiolytic
Midazolam Dormicum, Versed, Hypnovel, Dormonid 1985 0.5-1 1.5–2.5 hours (2h=0.08d) hypnotic, anticonvulsant, amnesic, anxiolytic
Nifoxipam Research chemical ? ? hypnotic
Nimetazepam Erimin 0.5-3 14–30 hours (27h=1.12d) hypnotic
Nitrazepam Mogadon, Alodorm, Pacisyn, Dumolid, Nitrazadon 1965 0.5-3 17–48 hours (32.5h=1.35d) hypnotic, anticonvulsant
Nordiazepam Madar, Stilny ? 30–150 hours (90h=3.75d) anxiolytic
Oxazepam Seresta, Serax, Serenid, Serepax, Sobril, Oxabenz, Oxapax, Opamox 1965 3-4 4–11 hours (7.5h=0.31d) anxiolytic
Phenazepam Phenazepam 1.5-4 60 hours (=2.5d) anxiolytic, anticonvulsant
Pinazepam Domar ? 40–100 hours (70h=2.92d) anxiolytic
Prazepam Lysanxia, Centrax N/A 2-6 36–200 hours (118h=4.92d) anxiolytic
Premazepam N/A 2-6 10–13 hours (11.5h=0.48d) anxiolytic
Pyrazolam Pyrazolam, Bromazolam Research chemical 1-1.5 16-18[17] hours (17h=0.71d) anxiolytic, amnesic
Quazepam Doral 1985 1-5 39–120 hours (79.5h=3.31d) hypnotic
Rilmazafone Rhythmy ? [10.5 hours] hypnotic
Temazepam Restoril, Normison, Euhypnos, Temaze, Tenox 1981 0.5-3 4–10.5 hours (7.25h=0.30d) hypnotic, anxiolytic, muscle relaxant
Thienalprazolam Thienalprazolam, Deschloroetizolam, Thialprazolam Research chemical 1-2 10–40 hours (25h=1.04d) anxiolytic
Tetrazepam Myolastan 1-3 3–26 hours (14.5h=0.60d) Muscle relaxant
Triazolam Halcion, Rilamir 1982 0.5-2 2 hours (=0.08d) hypnotic

Atypical benzodiazepine receptor ligands

Drug Name Common Brand Names* Approval Date (FDA) Elimination Half-Life (h)† [active metabolite] Primary Effects
DMCM  ?  ? anxiogenic, convulsant
Flumazenil** Anexate, Lanexat, Mazicon, Romazicon 1 hour antidote
Eszopiclone§ Lunesta 2004 6 hours hypnotic
Zaleplon§ Sonata, Starnoc 1999 1 hour hypnotic
Zolpidem§ Ambien, Nytamel, Sanval, Stilnoct, Stilnox, Sublinox (Canada), Xolnox, Zoldem, Zolnod 1992 2.6 hours hypnotic
Zopiclone§ Imovane, Rhovane, Ximovan; Zileze; Zimoclone; Zimovane; Zopitan; Zorclone, 4–6 hours hypnotic

* Not all trade names are listed. Click on drug name to see a more comprehensive list.

** Flumazenil is an imidazobenzodiazepine derivative,[18] and in layman's terms, it is a benzodiazepine overdose antidote that is given intravenously in Intensive Care Units (ICUs) to reverse the effects of benzodiazepine overdoses, as well for overdoses of the non-benzodiazepine "Z-drugs" such as Ambien and Lunesta.[19] Flumazenil is contraindicated for benzodiazepine-tolerant patients in overdose cases.[20] In such cases, the benefits are far outweighed by the risks, which include potential and severe seizures.[18][21] The method by which Flumazenil acts to prevent non-benzodiazepine tolerant overdose from causing potential harm is via preventing the benzodiazepines and Z-drugs from binding to the GABAA receptors via competitive inhibition which the Flumazenil creates. Clinical observation notating the patient's oxygen levels, respiratory, heart and blood pressure rates are used, as they are much safer than the potential seizure effects from Flumazenil. Supportive care to mediate any problems resulting from abnormal rates of the pulmonary, respiratory, and cardiovascular systems is typically the only treatment that is required in benzodiazepine-only overdoses.[22] In most cases, activated charcoal/carbon is often used to prevent benzodiazepines from being absorbed by the gastrointestinal tract, and the use of stomach-pumping/gastric lavage is no longer commonly used nor suggested by some toxicologists.[23] Even in cases where other central nervous system (CSN) depressants (such as in combined benzodiazepine and tricyclic antidepressant/TCA overdoses) are detected and/or suspected, endotrachial intubation for the airway path and supportive oxygen are typically implemented and are much safer than Flumazenil.[22]

Controversy

The UK's House of Commons has 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.[24][25]

Binding data and structure-activity relationship

A large number of benzodiazepine derivatives have been synthesised and their structure-activity relationships explored in detail.[26][27] This chart contains binding data for benzodiazepines and related drugs investigated by Roche up to the late 1990s (though in some cases the compounds were originally synthesised by other companies such as Takeda or Upjohn).[28][29][30][31][32][33] Other benzodiazepines are also listed for comparison purposes, but it does not however include binding data for;

While binding or activity data is 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 (i.e. sedation or anticonvulsant activity) but did not measure in vitro binding to benzodiazepine receptors.[35][36] 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 (e.g. flumazenil).
  • Low IC50 or high pIC50 values indicate tighter binding (pIC50 of 8.0 = IC50 of 10nM, pIC50 of 9.0 = IC50 of 1nM, etc.)
  • 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 (see e.g. CL-218,872)
  • 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,[37] 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.

See also

References

  1. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  2. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  3. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  4. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  5. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  6. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  7. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  8. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  9. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  10. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  11. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  12. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  13. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  14. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  15. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  16. ↑ Only active metabolites, chlornordiazepam and chloroxazepam, have appreciable effects, with 1.4 and 76 hour half-lives, respectively. See Psychomotor Effects of Mexazolam vs. Placebo in Healthy Volunteers, Clin Drug Invest. 2002;22(10)
  17. ↑ [1]
  18. ↑ 18.0 18.1 http://www.gene.com/download/pdf/romazicon_prescribing.pdf
  19. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  20. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  21. ↑ Gary R. Fleisher; Stephen Ludwig; Benjamin K. Silverman (2002). Synopsis of pediatric emergency medicine. Lippincott Williams & Wilkins. pp 409. ISBN 978-0-7817-3274-1. Retrieved 3/22/2013.
  22. ↑ 22.0 22.1 http://www.inchem.org/documents/pims/pharm/pim181.htm#DivisionTitle:8.1.1.1 Toxicological analyses. Retrieved 3/21/2013.)
  23. ↑ Vale JA, Kulig K; American Academy of Clinical Toxicology; European Association of Poisons Centres and Clinical Toxicologists. (2004). "Position paper: gastric lavage". J Toxicol Clin Toxicol 42 (7): 933–943. doi:10.1081/CLT-200045006. PMID 15641639
  24. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  25. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  26. ↑ Leo H Sternbach. The benzodiazepine story. Journal of Medicinal Chemistry 1979; 22(1):1-7. DOI: 10.1021/jm00187a001
  27. ↑ Hadjipavlou-Litina, D., & Hansch, C. (1994). Quantitative structure-activity relationships of the benzodiazepines. a review and reevaluation. Chemical Reviews, 94(6), 1483-1505. DOI: 10.1021/cr00030a002
  28. ↑ Haefely W, Kyburz E, Gerecke M, Mohler H. Recent advances in the molecular pharmacology of benzodiazepine receptors and in the structure-activity relationships of their agonists and antagonists. Adv. Drug Res. 1985, 14: 165-322.
  29. ↑ Winkler DA, Burden FR, Watkins AJR. Atomistic Topological Indices Applied to Benzodiazepines using Various Regression Methods. Quantitative Structure-Activity Relationships, January 1998; 17(01): 14-19.
  30. ↑ Thakur A, Thakur M, Khadikar P. Topological modeling of benzodiazepine receptor binding. Bioorg Med Chem. 2003 Nov 17;11(23):5203-7. PMID 14604684
  31. ↑ So, S. S., & Karplus, M. (1996). Genetic neural networks for quantitative structure-activity relationships: improvements and application of benzodiazepine affinity for benzodiazepine/GABAA receptors. Journal of Medicinal Chemistry, 39(26), 5246-5256. DOI: 10.1021/jm960536o
  32. ↑ Claus Braestrup and Mogens Nielsen. Benzodiazepine receptors. Biochemical Studies of CNS Receptors. Handbook of Psychopharmacology. (1983) Springer 2013. ISBN 9781468443615
  33. ↑ Zhang et al. Chemical and computer assisted development of an inclusive pharmacophore for the benzodiazepine receptor. Chapter 7, Biological Inhibitors. Volume 2 of Studies in medicinal chemistry. CRC Press, 2004. ISBN 9783718658794
  34. ↑ Moosmann, Bjoern; King, Leslie A.; Auwärter, Volker (2015). "Designer benzodiazepines: A new challenge". World Psychiatry 14 (2): 248–248. doi:10.1002/wps.20236. ISSN 1723-8617
  35. ↑ Blair T, Webb GA. Electronic factors in the structure-activity relationship of some 1,4-benzodiazepin-2-ones. J Med Chem. 1977 Sep;20(9):1206-10. PMID 926122
  36. ↑ Biagi GL, Barbaro AM, Guerra MC, Babbini M, Gaiardi M, Bartoletti M, Borea PA. Rm values and structure-activity relationship of benzodiazepines. J Med Chem. 1980 Feb;23(2):193-201. PMID 7359533
  37. ↑ Spencer J, Rathnam RP, Chowdhry BZ. 1,4-Benzodiazepin-2-ones in medicinal chemistry. Future Med Chem. 2010 Sep;2(9):1441-9. doi: 10.4155/fmc.10.226. PMID 21426139

Further reading

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