Clorazepate

Last updated
Clorazepate
Clorazepate.svg
Clorazepate3d.png
Clinical data
Trade names Tranxene, Tranxilium, Novo-Clopate
Other namesClorazepate dipotassium
AHFS/Drugs.com Monograph
MedlinePlus a682052
Routes of
administration 		Oral
ATC code
Legal status
Legal status
Pharmacokinetic data
Bioavailability 91%
Metabolism Hepatic
Elimination half-life 48 hours
Excretion Renal
Identifiers
  • (RS)-7-Chloro-2,3-dihydro-2-oxo-5-phenyl-1H-1,4-benzodiazepine-3-carboxylic acid
CAS Number
PubChem CID
IUPHAR/BPS
DrugBank
ChemSpider
UNII
KEGG
ChEMBL
CompTox Dashboard (EPA)
ECHA InfoCard 100.041.737 OOjs UI icon edit-ltr-progressive.svg
Chemical and physical data
Formula C16H11ClN2O3
Molar mass 314.73 g·mol−1
3D model (JSmol)
  • O=C(O)C1N=C(c2ccccc2)c2cc(Cl)ccc2NC1=O
  • InChI=1S/C16H11ClN2O3/c17-10-6-7-12-11(8-10)13(9-4-2-1-3-5-9)19-14(16(21)22)15(20)18-12/h1-8,14H,(H,18,20)(H,21,22) Yes check.svgY
  • Key:XDDJGVMJFWAHJX-UHFFFAOYSA-N X mark.svgN
 X mark.svgNYes check.svgY  (what is this?)    (verify)

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. [2]

Contents

It was patented in 1965 and approved for medical use in 1967. [3]

Medical uses

Clorazepate is used in the treatment of anxiety disorders and insomnia. It may also be prescribed as an anticonvulsant or muscle relaxant. [4] It is also used as a premedication. [5]

Clorazepate is prescribed principally in the treatment of alcohol withdrawal and epilepsy, although it is also a useful anxiolytic because of its long half-life. The normal starting dosage range of clorazepate is 15 to 60 mg per day. The drug is to be taken two to four times per day. Dosages as high as 90 to 120 mg per day may be used in the treatment of acute alcohol withdrawal. In the United States and Canada, clorazepate is available in 3.75, 7.5, and 15 mg capsules or tablets. In Europe, tablet formations are 5 mg, 10 mg, 20 mg and 50 mg. [6] Clorazepate SD (controlled release) is available and may have a reduced incidence of adverse effects. The sustained-release formulation of clorazepate has some advantages in that, if a dose is missed, less profound fluctuations in blood plasma levels occur, which may be helpful to some people with epilepsy at risk of break-through seizures. [7]

Adverse effects

Adverse effects of clorazepate include tolerance, dependence, withdrawal reactions, cognitive impairment, confusion, anterograde amnesia, falls in the elderly, ataxia, hangover effects, and drowsiness. It is unclear whether cognitive deficits resulting from the long-term use of benzodiazepines return to normal or persist indefinitely after withdrawal from benzodiazepines.[ citation needed ] Benzodiazepines are also known to cause or worsen depression. Paradoxical effects including excitement and paradoxical worsening of seizures can sometimes result from the use of benzodiazepines. Children, the elderly, individuals with a history of alcohol use disorder or a history of aggressive behavior and anger are at greater risk of developing paradoxical reactions to benzodiazepines. [7]

In September 2020, the U.S. Food and Drug Administration (FDA) required the boxed warning be updated for all benzodiazepine medicines to describe the risks of non-medical use, addiction, physical dependence, and withdrawal reactions consistently across all the medicines in the class. [8]

Tolerance, dependence and withdrawal

Delirium has been noted from discontinuation from clorazepate. [9] A benzodiazepine dependence occurs in approximately one third of patients who take benzodiazepines for longer than 4 weeks, which is characterised by a withdrawal syndrome upon dose reduction. When used for seizure control, tolerance may manifest itself with an increased rate of seizures as well an increased risk of withdrawal seizures. In humans, tolerance to the anticonvulsant effects of clorazepate occurs frequently with regular use. Due to the development of tolerance, benzodiazepines are, in general, not considered appropriate for the long-term management of epilepsy; increasing the dose may result only in the developing of tolerance to the higher dose combined with worsened adverse effects. Cross-tolerance occurs between benzodiazepines, meaning that, if individuals are tolerant to one benzodiazepine, they will display a tolerance to equivalent doses of other benzodiazepines. Withdrawal symptoms from benzodiazepines include a worsening of pre-existing symptoms as well as the appearance of new symptoms that were not pre-existing. The withdrawal symptoms may range from mild anxiety and insomnia to severe withdrawal symptoms such as seizures and psychosis. Withdrawal symptoms can be difficult in some cases to differentiate between pre-existing symptoms and withdrawal symptoms. Use of high doses, long-term use and abrupt or over-rapid withdrawal increases increase the severity of withdrawal syndrome. [7] However, tolerance to the active metabolite of clorazepate may occur more slowly than with other benzodiazepines. [7] Regular use of benzodiazepines causes the development of dependence characterised by tolerance to the therapeutic effects of benzodiazepines and the development of the benzodiazepine withdrawal syndrome including symptoms such as anxiety, apprehension, tremor, insomnia, nausea, and vomiting upon cessation of benzodiazepine use. Withdrawal from benzodiazepines should be gradual as abrupt withdrawal from high doses of benzodiazepines may cause confusion, toxic psychosis, convulsions, or a condition resembling delirium tremens. Abrupt withdrawal from lower doses may cause depression, nervousness, rebound insomnia, irritability, sweating, and diarrhea. [10]

Interactions

Clorazepate DOJ.jpg

All sedatives or hypnotics, e.g., other benzodiazepines, barbiturates, antiepileptic drugs, alcohol, antihistamines, opioids, neuroleptics, sleep aids are likely to magnify the effects of clorazepate (and each other) on the central nervous system. Drugs that may interact with clorazepate include, digoxin, disulfiram, fluoxetine, isoniazid, ketoconazole, levodopa, metoprolol, hormonal contraceptives, probenecid, propranolol, rifampin, theophylline, valproic acid. [4] Selective serotonin reuptake inhibitors, cimetidine, macrolide antibiotics and antimycotics inhibit the metabolism of benzodiazepines and may result in increased plasma levels with resultant enhancement of adverse effects. Phenytoin, phenobarbital, and carbamazepine have the opposite effect, with coadministration leading to increased metabolism and decreased therapeutic effects of clorazepate. [7]

Contraindications and special caution

Benzodiazepines require special precaution if used in the elderly, children, alcohol- or drug-dependent individuals and individuals with comorbid psychiatric disorders. [11]

Clorazepate if used late in pregnancy, the third trimester, causes a definite risk of severe benzodiazepine withdrawal syndrome in the neonate with symptoms including hypotonia, and reluctance to suck, to apnoeic spells, cyanosis, and impaired metabolic responses to cold stress. Floppy infant syndrome and sedation in the newborn may also occur. Symptoms of floppy infant syndrome and the neonatal benzodiazepine withdrawal syndrome have been reported to persist from hours to months after birth. [12]

Special precaution is required when using clorazepate in the elderly because the elderly metabolise clorazepate more slowly, which may result in excessive drug accumulation. Additionally the elderly are more sensitive to the adverse effects of benzodiazepines compared to younger individuals even when blood plasma levels are the same. Use of benzodiazepines in the elderly is only recommended for 2 weeks and it is also recommended that half of the usual daily dose is prescribed. [7]

Pharmacology

Clorazepate is a "classical" benzodiazepine. Other classical benzodiazepines include chlordiazepoxide, diazepam, clonazepam, oxazepam, lorazepam, nitrazepam, bromazepam and flurazepam. [13] Clorazepate is a long-acting benzodiazepine drug. [10] Clorazepate produces the active metabolite desmethyl-diazepam, which is a partial agonist of the GABAA receptor and has a half life of 20–179 hours; a small amount of desmethyldiazepam is further metabolised into oxazepam. Clorazepate exerts its pharmacological properties via increasing the opening frequency of the chloride ion channel of GABAA receptors. This effect of benzodiazepines requires the presence of the neurotransmitter GABA and results in enhanced inhibitory effects of the neurotransmitter GABA acting on GABAA receptors. [7] Clorazepate, like other benzodiazepines, is widely distributed and is highly bound to plasma proteins; clorazepate also crosses readily over the placenta and into breast milk. Peak plasma levels of the active metabolite desmethyl-diazepam are seen between 30 minutes and 2 hours after oral administration of clorazepate. Clorazepate is completely metabolised to desmethyl-diazepam in the gastrointestinal tract and thus the pharmacological properties of clorazepate are largely due to desmethyldiazepam. [7]

Chemistry

Clorazepate is used in the form of a dipotassium salt. It is unusual among benzodiazepines in that it is freely soluble in water.

Clorazepate can be synthesized starting from 2-amino-5-chlorobenzonitrile, which upon reaction with phenylmagnesium bromide is transformed into 2-amino-5-chlorbenzophenone imine. [14] [15] [16] Reacting this with aminomalonic ester gives a heterocyclization product, 7-chloro-1,3-dihydro-3-carbethoxy-5-phenyl-2H-benzodiazepin-2-one. Upon hydrolysis using an alcoholic solution of potassium hydroxide forms a dipotassium salt, chlorazepate.

Chlorazepate synthesis.png

In the United States, clorazepate is listed under Schedule IV of the Controlled Substances Act. [17]

Related Research Articles

<span class="mw-page-title-main">Benzodiazepine</span> Class of depressant drugs

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.

<span class="mw-page-title-main">Diazepam</span> Benzodiazepine sedative

Diazepam, sold under the brand name Valium among others, is a medicine of the benzodiazepine family that acts as an anxiolytic. It is used to treat a range of conditions, including anxiety, seizures, alcohol withdrawal syndrome, muscle spasms, insomnia, and restless legs syndrome. It may also be used to cause memory loss during certain medical procedures. It can be taken orally, as a suppository inserted into the rectum, intramuscularly, intravenously or used as a nasal spray. When injected intravenously, effects begin in one to five minutes and last up to an hour. When taken by mouth, effects begin after 15 to 60 minutes.

<span class="mw-page-title-main">Temazepam</span> Insomnia medication

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.

<span class="mw-page-title-main">Lorazepam</span> Benzodiazepine medication

Lorazepam, sold under the brand name Ativan among others, is a benzodiazepine medication. It is used to treat anxiety, trouble sleeping, severe agitation, active seizures including status epilepticus, alcohol withdrawal, and chemotherapy-induced nausea and vomiting. It is also used during surgery to interfere with memory formation and to sedate those who are being mechanically ventilated. It is also used, along with other treatments, for acute coronary syndrome due to cocaine use. It can be given orally, transdermally, intravenously (IV), or intramuscularly When given by injection, onset of effects is between one and thirty minutes and effects last for up to a day.

<span class="mw-page-title-main">Clonazepam</span> Benzodiazepine medication

Clonazepam, sold under the brand name Klonopin among others, is a benzodiazepine medication used to prevent and treat anxiety disorders, seizures, bipolar mania, agitation associated with psychosis, obsessive–compulsive disorder (OCD), and akathisia. It is a long-acting tranquilizer of the benzodiazepine class. It possesses anxiolytic, anticonvulsant, sedative, hypnotic, and skeletal muscle relaxant properties. It is typically taken orally but is also used intravenously. Effects begin within one hour and last between eight and twelve hours in adults.

<span class="mw-page-title-main">Nitrazepam</span> Benzodiazepine sedative

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.

<span class="mw-page-title-main">Bromazepam</span> Benzodiazepine drug

Bromazepam, sold under many brand names, is a benzodiazepine. It is mainly an anti-anxiety agent with similar side effects to diazepam. In addition to being used to treat anxiety or panic states, bromazepam may be used as a premedicant prior to minor surgery. Bromazepam typically comes in doses of 3 mg and 6 mg tablets.

<span class="mw-page-title-main">Flurazepam</span> Hypnotic medication

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.

<span class="mw-page-title-main">Oxazepam</span> Benzodiazepine medication

Oxazepam is a short-to-intermediate-acting benzodiazepine. Oxazepam is used for the treatment of anxiety, insomnia, and to control symptoms of alcohol withdrawal syndrome.

<span class="mw-page-title-main">Clobazam</span> Benzodiazepine class medication

Clobazam, sold under the brand names Frisium, Onfi and others, is a benzodiazepine class medication that was patented in 1968. Clobazam was first synthesized in 1966 and first published in 1969. Clobazam was originally marketed as an anxioselective anxiolytic since 1970, and an anticonvulsant since 1984. The primary drug-development goal was to provide greater anxiolytic, anti-obsessive efficacy with fewer benzodiazepine-related side effects.

<span class="mw-page-title-main">Nordazepam</span> Benzodiazepine derivative medication

Nordazepam is a 1,4-benzodiazepine derivative. Like other benzodiazepine derivatives, it has amnesic, anticonvulsant, anxiolytic, muscle relaxant, and sedative properties. However, it is used primarily in the treatment of anxiety disorders. It is an active metabolite of diazepam, chlordiazepoxide, clorazepate, prazepam, pinazepam, and medazepam.

<span class="mw-page-title-main">Loprazolam</span> Benzodiazepine

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.

<span class="mw-page-title-main">Prazepam</span> Benzodiazepine drug

Prazepam is a benzodiazepine derivative drug developed by Warner-Lambert in the 1960s. It possesses anxiolytic, anticonvulsant, sedative and skeletal muscle relaxant properties. Prazepam is a prodrug for desmethyldiazepam which is responsible for the therapeutic effects of prazepam.

<span class="mw-page-title-main">Lormetazepam</span> Benzodiazepine medication

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.

<span class="mw-page-title-main">Chlordiazepoxide</span> Benzodiazepine class sedative and hypnotic medication

Chlordiazepoxide, trade name Librium among others, is a sedative and hypnotic medication of the benzodiazepine class; it is used to treat anxiety, insomnia and symptoms of withdrawal from alcohol, benzodiazepines, and other drugs.

<span class="mw-page-title-main">Benzodiazepine withdrawal syndrome</span> Signs and symptoms due to benzodiazepine discontinuation in physically dependent persons

Benzodiazepine withdrawal syndrome is the cluster of signs and symptoms that may emerge when a person who has been taking benzodiazepines as prescribed develops a physical dependence on them and then reduces the dose or stops taking them without a safe taper schedule.

<span class="mw-page-title-main">Delorazepam</span> Benzodiazepine medication

Delorazepam, also known by the synonyms chlordesmethyldiazepam and nordiclazepam, is a drug which is a benzodiazepine and a derivative of desmethyldiazepam. It is marketed in Italy, where it is available under the trade name EN and Dadumir. Delorazepam (chlordesmethyldiazepam) is also an active metabolite of the benzodiazepine drugs diclazepam and cloxazolam. Adverse effects may include hangover type effects, drowsiness, behavioural impairments and short-term memory impairments. Similar to other benzodiazepines delorazepam has anxiolytic, skeletal muscle relaxant, hypnotic and anticonvulsant properties.

<span class="mw-page-title-main">Fosazepam</span> Benzodiazepam

Fosazepam is a drug which belonging to the benzodiazepine class of drugs, which are primarily anti-anxiety and sedative-hypnotic agents. It is a water soluble derivative of diazepam which has been substituted with a dimethylphosphoryl group to improve solubility in water. At equipotent doses, it possesses sedative and anxiolytic properties that are qualitatively and quantitatively similar to the effects of diazepam, with equal sedative-hypnotic, anti-convulsive, and muscle relaxant effects. In comparison to an equipotent dose of nitrazepam ,, its effects tended to be of noticeably milder magnitude.

<span class="mw-page-title-main">Benzodiazepine dependence</span> Medical condition

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.

<span class="mw-page-title-main">Benzodiazepine use disorder</span> Medical condition

Benzodiazepine use disorder (BUD), also called misuse or abuse, is the use of benzodiazepines without a prescription and/or for recreational purposes, which poses risks of dependence, withdrawal and other long-term effects. Benzodiazepines are one of the more common prescription drugs used recreationally. When used recreationally benzodiazepines are usually administered orally but sometimes they are taken intranasally or intravenously. Recreational use produces effects similar to alcohol intoxication.

References

  1. ↑ Anvisa (2023-03-31). "RDC Nº 784 - Listas de Substâncias Entorpecentes, Psicotrópicas, Precursoras e Outras sob Controle Especial" [Collegiate Board Resolution No. 784 - Lists of Narcotic, Psychotropic, Precursor, and Other Substances under Special Control] (in Brazilian Portuguese). Diário Oficial da União (published 2023-04-04). Archived from the original on 2023-08-03. Retrieved 2023-08-16.
  2. ↑ Ochs HR, Greenblatt DJ, Verburg-Ochs B, Locniskar A (October 1984). "Comparative single-dose kinetics of oxazolam, prazepam, and clorazepate: three precursors of desmethyldiazepam". Journal of Clinical Pharmacology. 24 (10): 446–451. doi:10.1002/j.1552-4604.1984.tb01817.x. PMID   6150943. S2CID   24414335. Archived from the original on 2009-07-20. Retrieved 2009-05-31.
  3. ↑ Fischer J, Ganellin CR (2006). Analogue-based Drug Discovery. John Wiley & Sons. p. 536. ISBN   9783527607495.
  4. 1 2 National Institutes of Health (2003). "Clorazepate". National Library of Medicine. Archived from the original on 20 May 2008. Retrieved 19 July 2008.
  5. ↑ Meybohm P, Hanss R, Bein B, Schaper C, Buttgereit B, Scholz J, Bauer M (September 2007). "[Comparison of premedication regimes. A randomized, controlled trial]". Der Anaesthesist. 56 (9): 890–2, 894–6. doi:10.1007/s00101-007-1208-7. PMID   17551699.
  6. ↑ Tranxene prescribing information in the Netherlands (Dutch language); accessed 2007-03-08.
  7. 1 2 3 4 5 6 7 8 Riss J, Cloyd J, Gates J, Collins S (August 2008). "Benzodiazepines in epilepsy: pharmacology and pharmacokinetics". Acta Neurologica Scandinavica. 118 (2): 69–86. doi: 10.1111/j.1600-0404.2008.01004.x . PMID   18384456. S2CID   24453988.[ dead link ]
  8. ↑ "FDA expands Boxed Warning to improve safe use of benzodiazepine drug". U.S. Food and Drug Administration (FDA). 23 September 2020. Retrieved 23 September 2020.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  9. ↑ Allgulander C, Borg S (June 1978). "Case report: a delirious abstinence syndrome associated with clorazepate (Tranxilen)". The British Journal of Addiction to Alcohol and Other Drugs. 73 (2): 175–177. doi:10.1111/j.1360-0443.1978.tb00139.x. PMID   27202.
  10. 1 2 Committee on the Review of Medicines (March 1980). "Systematic review of the benzodiazepines. Guidelines for data sheets on diazepam, chlordiazepoxide, medazepam, clorazepate, lorazepam, oxazepam, temazepam, triazolam, nitrazepam, and flurazepam". British Medical Journal. 280 (6218): 910–912. doi:10.1136/bmj.280.6218.910. PMC   1601049 . PMID   7388368.
  11. ↑ Authier N, Balayssac D, Sautereau M, Zangarelli A, Courty P, Somogyi AA, et al. (November 2009). "Benzodiazepine dependence: focus on withdrawal syndrome". Annales Pharmaceutiques Françaises. 67 (6): 408–413. doi:10.1016/j.pharma.2009.07.001. PMID   19900604.
  12. ↑ McElhatton PR (Nov 1994). "The effects of benzodiazepine use during pregnancy and lactation". Reproductive Toxicology. 8 (6): 461–475. Bibcode:1994RepTx...8..461M. doi:10.1016/0890-6238(94)90029-9. PMID   7881198.
  13. ↑ Braestrup C, Squires RF (April 1978). "Pharmacological characterization of benzodiazepine receptors in the brain". European Journal of Pharmacology. 48 (3): 263–270. doi:10.1016/0014-2999(78)90085-7. PMID   639854.
  14. ↑ US 3516988,Schmitt J,"1,4 benzodiazepine-2-ones having a carboxylic acid ester or amide group in the 3-position",issued 23 June 1970
  15. ↑ DE 1518764,Schmitt J,"Verfahren zur Herstellung von Orthoaminoarylcetiminen [Process for the preparation of orthoaminoarylcetimins]",published 1971-11-04, assigned to Etablissements Clin-Byla S.A.
  16. ↑ Schmitt J, Comoy P, Suguet M, Calief G, Muer J, Clim T, et al. (1969). "Sur des nouvelles benzodiazepines hydrosolubles douées d'une puissante activité sur le système nerveux central" [On new water-soluble benzodiazepines endowed with a powerful activity on the central nervous system.]. Chim. Ther. (in French). 4: 239.
  17. ↑ "List of Schedule 4 (IV) Controlled Substances". Drugs.com. Retrieved 27 March 2024.
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