Estazolam

Identification

Summary

Estazolam is a benzodiazepine used for the short-term management of insomnia.

Generic Name
Estazolam
DrugBank Accession Number
DB01215
Background

A benzodiazepine with anticonvulsant, hypnotic, and muscle relaxant properties. It has been shown in some cases to be more potent than diazepam or nitrazepam.

Type
Small Molecule
Groups
Approved, Illicit
Structure
Weight
Average: 294.738
Monoisotopic: 294.067224079
Chemical Formula
C16H11ClN4
Synonyms
  • 8-chloro-6-phenyl-4H-s-triazolo(4,3-a)(1,4)benzodiazepine
  • Estazolam
  • Estazolamum
External IDs
  • ABBOTT-47631

Pharmacology

Indication

For the short-term management of insomnia characterized by difficulty in falling asleep, frequent nocturnal awakenings, and/or early morning awakenings.

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Associated Conditions
Indication TypeIndicationCombined Product DetailsApproval LevelAge GroupPatient CharacteristicsDose Form
Management ofInsomnia••••••••••••
Contraindications & Blackbox Warnings
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Pharmacodynamics

Estazolam, a triazolobenzodiazepine derivative, is an oral hypnotic agent with anticonvulsant, hypnotic, and muscle relaxant properties. It has been shown in some cases to be more potent than diazepam or nitrazepam.

Mechanism of action

Benzodiazepines bind nonspecifically to benzodiazepine receptors, which affects affects muscle relaxation, anticonvulsant activity, motor coordination, and memory. As benzodiazepine receptors are thought to be coupled to gamma-aminobutyric acid-A (GABAA) receptors, this enhances the effects GABA by increasing GABA affinity for the GABA receptor. Binding of the inhibitory neurotransmitter GABA to the site opens the chloride channel, resulting in a hyperpolarized cell membrane that prevents further excitation of the cell.

TargetActionsOrganism
AGABA(A) Receptor
positive allosteric modulator
Humans
AGABA(A) Receptor Benzodiazepine Binding Site
ligand
Humans
Absorption

Tablets have been found to be equivalent in absorption to an orally administered solution of estazolam. In healthy subjects who received up to three times the recommended dose, peak estazolam plasma concentrations occurred within two hours after dosing (range 0.5 to 6.0 hours) and were proportional to the administered dose, suggesting linear pharmacokinetics over the dosage range tested.

Volume of distribution

Not Available

Protein binding

93% protein bound, independant of concentration.

Metabolism

Extensively metabolized in the liver. In vitro studies with human liver microsomes indicate that the biotransformation of estazolam to the major circulating metabolite 4-hydroxy-estazolam is mediated by cytochrome P450 3A (CYP3A).

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Route of elimination

Estazolam is extensively metabolized. The elimination of the parent drug takes place via hepatic metabolism of estazolam to hydroxylated and other metabolites that are eliminated largely in the urine both free and conjugated. Less than 5% of a 2 mg dose of estazolam was excreted unchanged in the urine, with only 4% of the dose appearing in the feces. Radiolabel mass balance studies indicate that the main route of excretion is via the kidneys. After 5 days, 87% of the administered radioactivity was excreted in human urine. Less than 4% of the dose was excreted unchanged.

Half-life

The range of estimates for the mean elimination half-life of estazolam varies from 10 to 24 hours.

Clearance

Not Available

Adverse Effects
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Toxicity

Symptoms of overdose include confusion, depressed breathing, drowsiness and eventually coma, lack of coordination, and slurred speech.

Pathways
Not Available
Pharmacogenomic Effects/ADRs Browse all" title="About SNP Mediated Effects/ADRs" id="snp-actions-info" class="drug-info-popup" href="javascript:void(0);">
Not Available

Interactions

Drug Interactions Learn More" title="About Drug Interactions" id="structured-interactions-info" class="drug-info-popup" href="javascript:void(0);">
This information should not be interpreted without the help of a healthcare provider. If you believe you are experiencing an interaction, contact a healthcare provider immediately. The absence of an interaction does not necessarily mean no interactions exist.
DrugInteraction
1,2-BenzodiazepineThe risk or severity of CNS depression can be increased when Estazolam is combined with 1,2-Benzodiazepine.
AbacavirAbacavir may decrease the excretion rate of Estazolam which could result in a higher serum level.
AbametapirThe serum concentration of Estazolam can be increased when it is combined with Abametapir.
AceclofenacAceclofenac may decrease the excretion rate of Estazolam which could result in a higher serum level.
AcemetacinAcemetacin may decrease the excretion rate of Estazolam which could result in a higher serum level.
Food Interactions
  • Avoid alcohol.
  • Take with or without food. The absorption is unaffected by food.

Products

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Product Images
International/Other Brands
Esilgan (Takeda) / Eurodin (Takeda) / Nuctalon (Takeda)
Brand Name Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing EndRegionImage
ProsomTablet2 mg/1OralAbbvie1990-12-312008-03-31US flag
ProsomTablet1 mg/1OralAbbvie1990-12-262008-03-31US flag
Prosom Tab 1mgTablet1 mg / tabOralAbbott1993-12-311997-08-18Canada flag
Prosom Tab 2mgTablet2 mg / tabOralAbbott1993-12-311997-08-18Canada flag
Generic Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing EndRegionImage
EstazolamTablet1 mg/1OralPar Pharmaceutical2004-01-262006-01-26US flag
EstazolamTablet2 mg/1OralGolden State Medical Supply1997-08-192013-12-31US flag
EstazolamTablet2 mg/1OralNovitium Pharma Llc2021-04-08Not applicableUS flag
EstazolamTablet1 mg/1OralMayne Pharma2020-10-18Not applicableUS flag
EstazolamTablet1 mg/1OralPar Pharmaceutical2009-06-302009-06-30US flag

Categories

ATC Codes
N05CD04 — Estazolam
Drug Categories
Chemical TaxonomyProvided by Classyfire
Description
This compound belongs to the class of organic compounds known as 1,2,4-triazolo[4,3-a][1,4]benzodiazepines. These are aromatic compounds containing a 1,4-benzodiazepine fused to and sharing a nitrogen atom with a 1,2,4-triazole ring.
Kingdom
Organic compounds
Super Class
Organoheterocyclic compounds
Class
Benzodiazepines
Sub Class
1,4-benzodiazepines
Direct Parent
1,2,4-triazolo[4,3-a][1,4]benzodiazepines
Alternative Parents
Benzene and substituted derivatives / Aryl chlorides / Triazoles / Heteroaromatic compounds / Ketimines / Propargyl-type 1,3-dipolar organic compounds / Azacyclic compounds / Organopnictogen compounds / Organochlorides / Hydrocarbon derivatives
Substituents
1,2,4-triazole / 1,2,4-triazolo[4,3-a][1,4]benzodiazepine / Aromatic heteropolycyclic compound / Aryl chloride / Aryl halide / Azacycle / Azole / Benzenoid / Heteroaromatic compound / Hydrocarbon derivative
Molecular Framework
Aromatic heteropolycyclic compounds
External Descriptors
triazoles, triazolobenzodiazepine (CHEBI:4858)
Affected organisms
  • Humans and other mammals

Chemical Identifiers

UNII
36S3EQV54C
CAS number
29975-16-4
InChI Key
CDCHDCWJMGXXRH-UHFFFAOYSA-N
InChI
InChI=1S/C16H11ClN4/c17-12-6-7-14-13(8-12)16(11-4-2-1-3-5-11)18-9-15-20-19-10-21(14)15/h1-8,10H,9H2
IUPAC Name
12-chloro-9-phenyl-2,4,5,8-tetraazatricyclo[8.4.0.0^{2,6}]tetradeca-1(10),3,5,8,11,13-hexaene
SMILES
ClC1=CC2=C(C=C1)N1C=NN=C1CN=C2C1=CC=CC=C1

References

Synthesis Reference

Hester, J.B. Jr.; U.S. Patent 3,701,782; October 31, 1972; assigned to The Upjohn Co.

General References
  1. Watanabe S, Ohta H, Sakurai Y, Takao K, Ueki S: [Electroencephalographic effects of 450191-S and its metabolites in rabbits with chronic electrode implants]. Nihon Yakurigaku Zasshi. 1986 Jul;88(1):19-32. [Article]
  2. Oishi R, Nishibori M, Itoh Y, Saeki K: Diazepam-induced decrease in histamine turnover in mouse brain. Eur J Pharmacol. 1986 May 27;124(3):337-42. [Article]
  3. Usami N, Yamamoto T, Shintani S, Ishikura S, Higaki Y, Katagiri Y, Hara A: Substrate specificity of human 3(20)alpha-hydroxysteroid dehydrogenase for neurosteroids and its inhibition by benzodiazepines. Biol Pharm Bull. 2002 Apr;25(4):441-5. [Article]
Human Metabolome Database
HMDB0015346
KEGG Drug
D00311
KEGG Compound
C06981
PubChem Compound
3261
PubChem Substance
46507430
ChemSpider
3146
BindingDB
50240450
RxNav
4077
ChEBI
4858
ChEMBL
CHEMBL285674
ZINC
ZINC000000001370
Therapeutic Targets Database
DAP000930
PharmGKB
PA449502
RxList
RxList Drug Page
Drugs.com
Drugs.com Drug Page
PDRhealth
PDRhealth Drug Page
Wikipedia
Estazolam

Clinical Trials

Clinical Trials Learn More" title="About Clinical Trials" id="clinical-trials-info" class="drug-info-popup" href="javascript:void(0);">
PhaseStatusPurposeConditionsCount
4CompletedTreatmentPrimary Insomnia / Sleep Initiation and Maintenance Disorders1
4Unknown StatusTreatmentRenal Dialysis / Sleep Initiation and Maintenance Disorders1
3CompletedTreatmentSleep Initiation and Maintenance Disorders1
Not AvailableNot Yet RecruitingTreatmentShort-term Insomnia1
Not AvailableRecruitingTreatmentCircadian Rhythms / Insomnia Chronic / Traditional Chinese Medicine1

Pharmacoeconomics

Manufacturers
Not Available
Packagers
  • Abbott Laboratories Ltd.
  • Dispensing Solutions
  • Lake Erie Medical and Surgical Supply
  • Murfreesboro Pharmaceutical Nursing Supply
  • Par Pharmaceuticals
  • Rebel Distributors Corp.
  • Southwood Pharmaceuticals
  • Teva Pharmaceutical Industries Ltd.
  • Watson Pharmaceuticals
Dosage Forms
FormRouteStrength
TabletOral
Solution / dropsOral1 MG/ML
TabletOral1 MG
TabletOral2 MG
TabletOral1 mg/1
TabletOral2 mg/1
TabletOral1 mg / tab
TabletOral2 mg / tab
TabletOral2.000 mg
Prices
Unit descriptionCostUnit
Prosom 2 mg tablet1.71USD tablet
Prosom 1 mg tablet1.53USD tablet
Estazolam 2 mg tablet0.96USD tablet
Estazolam 1 mg tablet0.86USD tablet
DrugBank does not sell nor buy drugs. Pricing information is supplied for informational purposes only.
Patents
Not Available

Properties

State
Solid
Experimental Properties
PropertyValueSource
melting point (°C)228-229Hester, J.B. Jr.; U.S. Patent 3,701,782; October 31, 1972; assigned to The Upjohn Co.
water solubilityPractically insoluble (1.5 mg/L)Not Available
logP4.7Not Available
Predicted Properties
PropertyValueSource
Water Solubility0.0423 mg/mLALOGPS
logP1.72ALOGPS
logP2.9Chemaxon
logS-3.8ALOGPS
pKa (Strongest Acidic)18.3Chemaxon
pKa (Strongest Basic)4.9Chemaxon
Physiological Charge0Chemaxon
Hydrogen Acceptor Count3Chemaxon
Hydrogen Donor Count0Chemaxon
Polar Surface Area43.07 Å2Chemaxon
Rotatable Bond Count1Chemaxon
Refractivity94.44 m3·mol-1Chemaxon
Polarizability29.83 Å3Chemaxon
Number of Rings4Chemaxon
Bioavailability1Chemaxon
Rule of FiveYesChemaxon
Ghose FilterYesChemaxon
Veber's RuleNoChemaxon
MDDR-like RuleNoChemaxon
Predicted ADMET Features
PropertyValueProbability
Human Intestinal Absorption+1.0
Blood Brain Barrier+0.9796
Caco-2 permeable+0.8427
P-glycoprotein substrateNon-substrate0.5939
P-glycoprotein inhibitor INon-inhibitor0.7883
P-glycoprotein inhibitor IIInhibitor0.7786
Renal organic cation transporterInhibitor0.7784
CYP450 2C9 substrateNon-substrate0.8367
CYP450 2D6 substrateNon-substrate0.9081
CYP450 3A4 substrateSubstrate0.674
CYP450 1A2 substrateInhibitor0.8989
CYP450 2C9 inhibitorInhibitor0.822
CYP450 2D6 inhibitorNon-inhibitor0.8586
CYP450 2C19 inhibitorInhibitor0.6571
CYP450 3A4 inhibitorNon-inhibitor0.6818
CYP450 inhibitory promiscuityHigh CYP Inhibitory Promiscuity0.8676
Ames testNon AMES toxic0.9132
CarcinogenicityNon-carcinogens0.7126
BiodegradationNot ready biodegradable1.0
Rat acute toxicity2.0584 LD50, mol/kg Not applicable
hERG inhibition (predictor I)Weak inhibitor0.9752
hERG inhibition (predictor II)Non-inhibitor0.8944
ADMET data is predicted using admetSAR, a free tool for evaluating chemical ADMET properties. (23092397)

Spectra

Mass Spec (NIST)
Not Available
Spectra
SpectrumSpectrum TypeSplash Key
Predicted GC-MS Spectrum - GC-MSPredicted GC-MSsplash10-016r-2190000000-7bceaaf0dfe0270e210a
Mass Spectrum (Electron Ionization)MSsplash10-0a4u-4590000000-dbd088d66293b3b539c3
Predicted MS/MS Spectrum - 10V, Positive (Annotated)Predicted LC-MS/MSsplash10-0002-0090000000-16e75d578f20a76b34f4
Predicted MS/MS Spectrum - 10V, Negative (Annotated)Predicted LC-MS/MSsplash10-0006-0090000000-463e81c5324b33363826
Predicted MS/MS Spectrum - 20V, Positive (Annotated)Predicted LC-MS/MSsplash10-0002-0090000000-16e75d578f20a76b34f4
Predicted MS/MS Spectrum - 20V, Negative (Annotated)Predicted LC-MS/MSsplash10-0006-0090000000-9d154acb0d52e13ad708
Predicted MS/MS Spectrum - 40V, Positive (Annotated)Predicted LC-MS/MSsplash10-00kb-0090000000-ba640717929e3ab20b92
Predicted MS/MS Spectrum - 40V, Negative (Annotated)Predicted LC-MS/MSsplash10-014i-0090000000-f5df879a2dcb8461fabe
Predicted MS/MS Spectrum - 10V, Positive (Annotated)Predicted LC-MS/MSsplash10-0002-0090000000-16e75d578f20a76b34f4
Predicted MS/MS Spectrum - 10V, Negative (Annotated)Predicted LC-MS/MSsplash10-0006-0090000000-463e81c5324b33363826
Predicted MS/MS Spectrum - 20V, Positive (Annotated)Predicted LC-MS/MSsplash10-0002-0090000000-16e75d578f20a76b34f4
Predicted MS/MS Spectrum - 20V, Negative (Annotated)Predicted LC-MS/MSsplash10-0006-0090000000-9d154acb0d52e13ad708
Predicted MS/MS Spectrum - 40V, Positive (Annotated)Predicted LC-MS/MSsplash10-00kb-0090000000-ba640717929e3ab20b92
Predicted MS/MS Spectrum - 40V, Negative (Annotated)Predicted LC-MS/MSsplash10-014i-0090000000-f5df879a2dcb8461fabe
Predicted 1H NMR Spectrum1D NMRNot Applicable
Predicted 13C NMR Spectrum1D NMRNot Applicable
Chromatographic Properties
Collision Cross Sections (CCS)
AdductCCS Value (Å2)Source typeSource
[M-H]-168.4597181
predicted
DarkChem Lite v0.1.0
[M-H]-161.69096
predicted
DeepCCS 1.0 (2019)
[M-H]-168.4597181
predicted
DarkChem Lite v0.1.0
[M-H]-161.69096
predicted
DeepCCS 1.0 (2019)
[M+H]+169.1288181
predicted
DarkChem Lite v0.1.0
[M+H]+164.04898
predicted
DeepCCS 1.0 (2019)
[M+H]+169.1288181
predicted
DarkChem Lite v0.1.0
[M+H]+164.04898
predicted
DeepCCS 1.0 (2019)
[M+Na]+168.9050181
predicted
DarkChem Lite v0.1.0
[M+Na]+170.14214
predicted
DeepCCS 1.0 (2019)
[M+Na]+168.9050181
predicted
DarkChem Lite v0.1.0
[M+Na]+170.14214
predicted
DeepCCS 1.0 (2019)

Targets

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Kind
Protein group
Organism
Humans
Pharmacological action
Yes
Actions
Positive allosteric modulator
Curator comments
The GABA(A) receptor is pentameric (i.e. comprising 5 subunit proteins) and therefore has a multitude of potential isoforms. The above target is a collection of all possible GABA(A) subunits that may participate in the formation of the pentameric receptor and is not meant to imply direct a drug-protein interaction for each individual subunit.
General Function
Inhibitory extracellular ligand-gated ion channel activity
Specific Function
Component of the heteropentameric receptor for GABA, the major inhibitory neurotransmitter in the vertebrate brain. Functions also as histamine receptor and mediates cellular responses to histamine...

Components:
References
  1. Sigel E, Steinmann ME: Structure, function, and modulation of GABA(A) receptors. J Biol Chem. 2012 Nov 23;287(48):40224-31. doi: 10.1074/jbc.R112.386664. Epub 2012 Oct 4. [Article]
  2. Zhu S, Noviello CM, Teng J, Walsh RM Jr, Kim JJ, Hibbs RE: Structure of a human synaptic GABAA receptor. Nature. 2018 Jul;559(7712):67-72. doi: 10.1038/s41586-018-0255-3. Epub 2018 Jun 27. [Article]
Kind
Protein group
Organism
Humans
Pharmacological action
Yes
Actions
Ligand
Curator comments
Benzodiazepines modulate GABA(A) function by binding at the interface between alpha (α) and gamma (γ) subunits. Of the 6 α-subunits, only 4 (α-1, -2, -3, and -5) participate in the formation of this binding site. The above target is a collection of all α- and γ-subunits that are known to participate in the formation of the benzodiazepine binding site.
General Function
Inhibitory extracellular ligand-gated ion channel activity
Specific Function
Component of the heteropentameric receptor for GABA, the major inhibitory neurotransmitter in the vertebrate brain. Functions also as histamine receptor and mediates cellular responses to histamine...

Components:
References
  1. Sigel E, Steinmann ME: Structure, function, and modulation of GABA(A) receptors. J Biol Chem. 2012 Nov 23;287(48):40224-31. doi: 10.1074/jbc.R112.386664. Epub 2012 Oct 4. [Article]
  2. Zhu S, Noviello CM, Teng J, Walsh RM Jr, Kim JJ, Hibbs RE: Structure of a human synaptic GABAA receptor. Nature. 2018 Jul;559(7712):67-72. doi: 10.1038/s41586-018-0255-3. Epub 2018 Jun 27. [Article]

Enzymes

Kind
Protein
Organism
Humans
Pharmacological action
Unknown
Actions
Substrate
General Function
Vitamin d3 25-hydroxylase activity
Specific Function
Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It performs a variety of oxidation react...
Gene Name
CYP3A4
Uniprot ID
P08684
Uniprot Name
Cytochrome P450 3A4
Molecular Weight
57342.67 Da
References
  1. Miura M, Otani K, Ohkubo T: Identification of human cytochrome P450 enzymes involved in the formation of 4-hydroxyestazolam from estazolam. Xenobiotica. 2005 May;35(5):455-65. [Article]

Drug created at June 13, 2005 13:24 / Updated at February 21, 2021 18:51