List of benzodiazepines

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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 anti hypertension medications). Variation in potency of certain effects may exist among 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 or 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 important to note that the 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 metabolise benzodiazepines more slowly. Many doctors[who?] make the mistake of not adjusting benzodiazepine dosage according to age in elderly patients. Thus the approximate equivalent doses below may need to be adjusted accordingly in individuals on short acting benzodiazepines who metabolise 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 up to 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]

Dose equivalency table[edit]


per Ashton "Benzodiazepine Equivalency Table"[9]

Drug Name Common Brand Names* Time to Peak (Onset of action in hours) Elimination Half-Life (h) [active metabolite] Therapeutic use Approximate Equivalent Dose
Alprazolam Helex, Xanax, Xanor, Onax, Alprox, Restyl, Tafil, 1-2 9–20 hours anxiolytic 1 mg
Bretazenil[10] N/A ? 2.5 hours anxiolytic, anticonvulsant 0.5 mg
Bromazepam Lectopam, Lexaurin, Lexotanil, Lexotan, Bromam 1-3 10–20 hours anxiolytic 5–6 mg
Brotizolam Lendormin, Dormex, Sintonal, Noctilan 0.5-2 4–5 hours hypnotic 0.25 mg
Chlordiazepoxide Librium, Risolid, Elenium 1.5-4 5–30 hours [36–200 hours] anxiolytic 25 mg
Cinolazepam Gerodorm 0.5-2 9 hours sedative 40 mg
Clonazepam Rivatril, Rivotril, Klonopin, Iktorivil, Paxam 1-4 18–50 hours anxiolytic, anticonvulsant 0.5 mg
Clorazepate Tranxene, Tranxilium Variable 36–100 hours anxiolytic, anticonvulsant 15 mg
Clotiazepam Veratran, Clozan, Rize 1-3 6–18 hours anxiolytic 5–10 mg
Cloxazolam Sepazon, Olcadil 2-5 (?) 18–50 hours anxiolytic, anticonvulsant 1 mg
Delorazepam Dadumir 1-2 60–140 hours anxiolytic 1 mg
Diazepam Antenex, Apaurin, Apzepam, Apozepam, Hexalid, Pax, Stesolid, Stedon, Valium, Vival, Valaxona 1-1.5 20–100 hours [36–200] anxiolytic, anticonvulsant, muscle relaxant 10 mg
Diclazepam[11] N/A 1.5-4 (4-6) 42–220 hours [10–200 (metabolites)] anxiolytic, anticonvulsant, hypnotic muscle relaxant, sedative, skeletal muscle relaxant 1-1.5 mg
Estazolam ProSom 1-5 10–24 hours hypnotic 2 mg
Etizolam Etilaam, Etizest, Pasaden, Depas 1-2 6 hours anxiolytic, hypnotic 1 mg
Ethyl loflazepate Victan, Meilax, Ronlax 1.5 50–100 hours anxiolytic 2 mg
Flubromazepam[12] N/A 1.5-4 (4-8) 100–220 hours anxiolytic, anticonvulsant, hypnotic muscle relaxant, sedative 4-6 mg
Flunitrazepam Rohypnol, Hipnosedon, Vulbegal, Fluscand, Flunipam, Ronal, Rohydorm, 0.5-3 18–26 hours [36–200 hours] hypnotic 1 mg
Flurazepam Dalmadorm, Dalmane 1-1.5 40–250 hours hypnotic 15–30 mg
Flutoprazepam Restas 0.5-9 60–90 hours hypnotic, anticonvulsant 2–3 mg
Halazepam Paxipam 1-3 30–100 hours anxiolytic 20–40 mg
Ketazolam Anxon 2.5-3 30–100 hours [36–200] anxiolytic 15–30 mg
Loprazolam Dormonoct 0.5-4 6–12 hours hypnotic 2 mg
Lorazepam Ativan, Lorenin, Lorsilan, Temesta, Tavor, Lorabenz 2-4 10–20 hours anxiolytic, anticonvulsant 1 mg
Lormetazepam Loramet, Noctamid, Pronoctan 0.5-2 10–12 hours hypnotic 1.5 mg
Medazepam Nobrium, Ansilan, Mezapam, Rudotel, Raporan ? 36–200 hours anxiolytic 10 mg
Midazolam Dormicum, Versed, Hypnovel, Dormonid 0.5-1 3 hours (1.8–6 hours) hypnotic, anticonvulsant 7.5 mg
Nimetazepam Erimin 0.5-3 14–30 hours hypnotic 5 mg
Nitrazepam Mogadon, Alodorm, Pacisyn, Dumolid, Nitrazadon 0.5-7 15–38 hours hypnotic, anticonvulsant 10 mg
Nordazepam Madar, Stilny ? 50–120 hours anxiolytic 10 mg
Oxazepam Seresta, Serax, Serenid, Serepax, Sobril, Oxabenz, Oxapax, Opamox 3-4 4–15 hours anxiolytic 20 mg
Phenazepam Phenazepam 1.5-4 60 hours anxiolytic, anticonvulsant 1 mg
Pinazepam Domar ? 40–100 hours anxiolytic 20 mg
Prazepam Lysanxia, Centrax 2-6 36–200 hours anxiolytic 20 mg
Premazepam N/A 2-6 10–13 hours anxiolytic 15 mg
Pyrazolam N/A 1-1.5 16-18[13] hours anxiolytic 1 mg
Quazepam Doral 1-5 39–120 hours hypnotic 20 mg
Temazepam Restoril, Normison, Euhypnos, Temaze, Tenox 0.5-3 8–22 hours hypnotic 20 mg
Tetrazepam Myolastan 1-3 3–26 hours Skeletal muscle relaxant 100 mg
Triazolam Halcion, Rilamir 0.5-2 2 hours hypnotic 0.25 (.5 with oral bioavailability) mg

Atypical benzodiazepine receptor ligands[edit]

Drug Name Common Brand Names* Elimination Half-Life (h) [active metabolite] Primary Effects Approximate Equivalent Dose
Clobazam Frisium, Urbanol 8–60 hours anxiolytic, anticonvulsant 20 mg
DMCM  ?  ? anxiogenic, convulsant Non-applicable
Flumazenil** Anexate, Lanexat, Mazicon, Romazicon 1 hour antidote Typical dose 0.2 - 0.6 mgð
Eszopiclone§ Lunesta 6 hours hypnotic 3 mg
Zaleplon§ Sonata, Starnoc 1 hours hypnotic 20 mg
Zolpidem§ Ambien, Nytamel, Sanval, Stilnoct, Stilnox, Sublinox (Canada), Xolnox, Zoldem, Zolnod 2.6 hours hypnotic 20 mg
Zopiclone§ Imovane, Rhovane, Ximovan; Zileze; Zimoclone; Zimovane; Zopitan; Zorclone, 4–6 hours hypnotic 15 mg


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

Equivalent doses are based on clinical experience but may vary between individuals. http://www.benzo.org.uk/bzequiv.htm.

** Flumazenil is an imidazobenzodiazepine derivative,[14] 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.[15] Flumazenil is contraindicated for benzodiazepine-tolerant patients in overdose cases.[16] In such cases, the risks far outweigh the benefits, which include potential and severe seizures.[17][14] 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.[18] 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.[19] 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.[18]

Controversy[edit]

The Ashton Manual claims the potency of both Alprazolam and Clonazepam to be 0.5 mg equivalent to 10 mg of diazepam/Valium, whereas most sources give 1 mg equivalent to 10 mg diazepam.[20]

Another chart with different ratios can be seen at www.health.qld.gov.au/atod/documents/24904.pdf; Table 11, Section 5.8. It notes that 10 mg of Valium is equivalent to 1 mg of Xanax/Alprazolam and .50 – 1 mg of Klonopin/Clonazepam/Rivotril. (Australian Department of Health)

The UK's House of Commons began APPGITA/The All Party Parliamentary Group on Involuntary Tranquilliser Addiction. Since 2002, APPGITA has tried to politically mandate prescribing guidelines for benzodiazepines.[21] APPGITA 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.[22][23]

See also[edit]

References[edit]

  1. ^ Golombok S, Lader M (August 1984). "The psychopharmacological effects of premazepam, diazepam and placebo in healthy human subjects". Br J Clin Pharmacol 18 (2): 127–33. doi:10.1111/j.1365-2125.1984.tb02444.x. PMC 1463527. PMID 6148956. 
  2. ^ de Visser SJ, van der Post JP, de Waal PP, Cornet F, Cohen AF, van Gerven JM (January 2003). "Biomarkers for the effects of benzodiazepines in healthy volunteers" (PDF). Br J Clin Pharmacol 55 (1): 39–50. doi:10.1046/j.1365-2125.2002.t01-10-01714.x. PMC 1884188. PMID 12534639. 
  3. ^ "Benzodiazepine Names". non-benzodiazepines.org.uk. Retrieved 2009-04-05. 
  4. ^ C. Heather Ashton (March 2007). "Benzodiazepine Equivalence Table". benzo.org.uk. Retrieved 2009-04-05. 
  5. ^ Bob, Dr (July 1995). "Benzodiazepine Equivalence Charts". dr-bob.org. Retrieved 2009-04-05. 
  6. ^ Salzman, Carl (15 May 2004). Clinical geriatric psychopharmacology (4th ed.). USA: Lippincott Williams & Wilkins. pp. 450–453. ISBN 978-0-7817-4380-8. 
  7. ^ Delcò F, Tchambaz L, Schlienger R, Drewe J, Krähenbühl S (2005). "Dose adjustment in patients with liver disease". Drug Saf 28 (6): 529–45. doi:10.2165/00002018-200528060-00005. PMID 15924505. 
  8. ^ Riss, J.; Cloyd, J.; Gates, J.; Collins, S. (Aug 2008). "Benzodiazepines in epilepsy: pharmacology and pharmacokinetics.". Acta Neurol Scand 118 (2): 69–86. doi:10.1111/j.1600-0404.2008.01004.x. PMID 18384456. 
  9. ^ Ashton, Dr. Heather. "Benzodiazepine Equivalency Table". Retrieved 26 September 2013. 
  10. ^ van Steveninck AL et al. (1996). "Pharmacokinetic and pharmacodynamic interactions of bretazenil and diazepam with alcohol.". British Journal of Clinical Pharmacology 41 (6): 565–573. doi:10.1046/j.1365-2125.1996.38514.x. PMC 2042631. PMID 8799523. 
  11. ^ Moosmann, Bisel P, Auwärter V. (2014). "Characterization of the designer benzodiazepine diclazepam and preliminary data on its metabolism and pharmacokinetics.". The National Center for Biotechnology 1: 1. PMID 24604775. 
  12. ^ J Mass Spectrom (2013). "Detection and identification of the designer benzodiazepine flubromazepam and preliminary data on its metabolism and pharmacokinetics.". The National Center for Biotechnology 1: 1. PMID 24259203. 
  13. ^ [1][dead link]
  14. ^ a b http://www.gene.com/download/pdf/romazicon_prescribing.pdf
  15. ^ "Flumazenil Injection, Solution [App Pharmaceuticals, Llc]". Dailymed.nlm.nih.gov. Retrieved 2014-08-15. 
  16. ^ "DailyMed". Dailymed.nlm.nih.gov. Retrieved 2014-08-15. 
  17. ^ 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.
  18. ^ a b http://www.inchem.org/documents/pims/pharm/pim181.htm#DivisionTitle:8.1.1.1 Toxicological analyses. Retrieved 3/21/2013.)
  19. ^ 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
  20. ^ http://www.csam-asam.org/sites/default/files/pdf/misc/TIP_45.pdf, Page 76. US Department of Health and Human Services, 2006. Retrieved 3/23/12.)
  21. ^ "Early Day Motion, Launched 18 November 2002". Appgita. 2002-11-18. Retrieved 2014-08-15. 
  22. ^ "November | 2002". Appgita. Retrieved 2014-08-15. 
  23. ^ "APPG for Involuntary Tranquilliser Addiction". benzo.org.uk. Retrieved 2014-08-15. 

Further reading[edit]